JP2016179499A - Method and system for additive manufacture using high energy source and hot wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a system for additive manufacture using a high energy source and a hot wire.SOLUTION: A method and a system for manufacturing a workpiece use: a high-intensity energy source to form a molten pool through use of the high-intensity energy source; and at least one wire which is heated to a melting point or a temperature close thereto through resistive heating and accumulated in the melting pool as a droplet.SELECTED DRAWING: None

Description

This application is a continuation-in-part of US Patent Application No. 14 / 163,367, filed on January 24, 2014, and claims the priority thereof. See the full text of the application. Is incorporated herein by reference.

  Certain embodiments relate to additive manufacturing applications. More particularly, certain embodiments relate to systems and methods that use a combination filler wire delivery and energy source system for additive manufacturing applications.

  The use of additive manufacturing has grown in recent years using various methods. However, the known methods have various drawbacks. For example, some processes use metal powder, which is generally slow and can cause a significant amount of powder to be wasted. Other methods using arc welding are also slow and cannot produce highly precise molded products. Therefore, there is a need for an additional manufacturing process and system capable of high precision and high speed operation.

  Other limitations and shortcomings of the traditional, proposed schemes can be obtained by comparing such schemes with the embodiments of the present invention described in the remainder of this application with respect to the drawings. It will be clear to the contractor.

US patent application Ser. No. 13 / 212,025

  Embodiments of the present invention include systems and methods for additive manufacturing in which a high energy device irradiates a surface of a workpiece with a high energy discharge to form a molten pool on the surface of the workpiece. A wire feeder delivers the wire to the molten pool, and a power supply supplies a heating signal to the wire, which includes a plurality of current pulses, each of which has a droplet at the tip of the wire. Forming and depositing it in the molten pool. Each of the current pulses reaches a peak current level after the wire feeder has brought the tip of the wire into contact with the molten pool, and the heating signal has no current between the plurality of current pulses. The wire feeder controls the movement of the wire so that the tip of the wire is not in contact with the weld pool between successive peak current levels of the current pulse, and the power source provides heating current between the wire and the workpiece during the current pulse. Control to prevent arcing.

  These and / or other aspects of the invention will become more apparent from the detailed description of exemplary embodiments of the invention with reference to the accompanying drawings, in which:

FIG. 1 shows a schematic block diagram of an exemplary embodiment of the additive manufacturing system of the present invention. 2A-D illustrate a droplet deposition process according to an embodiment of the present invention. FIG. 3 shows another view of a droplet deposition process according to an exemplary embodiment of the present invention. 4A-B show typical current waveforms that can be used in embodiments of the present invention. FIG. 5 shows an exemplary embodiment of the voltage and current waveforms of the present invention. 6A-B illustrate the use of a laser to assist droplet deposition. FIG. 7 illustrates an exemplary embodiment of a wire heating system according to certain aspects of the present invention. FIG. 8A shows an exemplary embodiment of a current waveform that can be used in the system of FIG. FIG. 8B shows an exemplary embodiment of current, voltage, wire feed rate, and laser power waveforms for an embodiment of the present invention. FIG. 9 illustrates another exemplary embodiment of the wire heating system of the present invention. FIG. 10 illustrates another exemplary embodiment of the present invention that uses multiple wires. FIG. 11 illustrates another exemplary embodiment of the system of the present invention. FIG. 12 illustrates a power supply system according to an embodiment of the present invention. FIG. 13 illustrates an embodiment of a system that uses multiple welding materials at a time. FIG. 14 shows another embodiment of the system of FIG. FIG. 15 shows another exemplary embodiment of the system shown in FIG. FIG. 16 illustrates an exemplary embodiment of a non-adhesive manufacturing substrate. 17A-C show another exemplary embodiment of a non-adhesive manufacturing substrate. FIG. 18A shows an embodiment of a non-bonded substrate having a cooling system. FIG. 18B shows an exemplary embodiment of a manufacturing truss structure that can be used in an embodiment of an embodiment of the present invention. 19A-C illustrate an exemplary embodiment of a braided additive manufacturing weld material that can be used in the system described herein. FIGS. 20A-B illustrate an exemplary braided weld material after deformation, according to an embodiment of the present invention. FIG. 20C illustrates an embodiment of a dual wire deposited contact tip as described herein. FIG. 20D shows another exemplary embodiment of the dual wire contact tip of the present invention. FIGS. 21A-B illustrate certain exemplary contact tip assemblies of the present invention that can be used to deform the weld material for delivery during the deposition process. FIG. 22 shows another exemplary welding material of the present invention. FIG. 23 illustrates another exemplary embodiment of the additive manufacturing welding material described herein. Figures 24A-D illustrate another exemplary embodiment of an additive manufacturing welding material that can be used in embodiments of the present invention.

  Exemplary embodiments of the present invention will now be described below with reference to the accompanying drawings. The described exemplary embodiments are intended to aid the understanding of the present invention and are not intended to limit the scope of the invention in any way. Like reference numerals refer to like elements throughout.

  The term “additional manufacturing” is used herein in a broad sense and may refer to any application that involves the construction, construction, or creation of objects or components.

FIG. 1 shows a functional schematic block diagram of an exemplary embodiment of a combination filler wire feeder and energy source system 100 for performing additive manufacturing. System 100 includes a laser subsystem that can focus laser beam 110 onto workpiece 115 and heat workpiece 115. The laser subsystem is a high intensity energy source. The laser subsystem may be any type of high energy laser source, including but not limited to carbon dioxide, Nd: YAG, Yb-disk, YB-fiber, fiber transmission or direct diode laser systems. Not. Other embodiments of the system include an electron beam that functions as a high intensity energy source, a plasma arc welding subsystem, a gas tungsten arc welding subsystem, a gas metal arc welding subsystem, a flux cored wire arc welding subsystem, and a submerged arc welding. At least one of the subsystems may be included. In the following specification, reference will be made repeatedly to laser systems, beams and power supplies, but it should be understood that this reference is only an example as any high intensity energy source can be used. For example, high-strength energy source capable of supplying at least 500 W / cm ^2. The laser subsystem includes a laser device 120 and a laser power supply 130 that are operatively connected to each other. The laser power source 130 supplies power for operating the laser device 120.

  The system 100 also includes a hot filler wire feeder that can supply at least one resistive filler wire 140 to contact the workpiece 115 in the vicinity of the laser beam 110. Of course, it should be understood that when reference is made herein to the workpiece 115, the molten pool is also considered to be part of the workpiece 115, and thus any reference to contact with the workpiece 115 is referred to as a molten pool. Including contact with. The wire feeder subsystem includes a filler wire feeder 150, a contact tube 160, and a power source 170. During operation, the filler wire 140 is resistively heated by current from a power source 170 that is operatively connected between the contact tube 160 and the workpiece 115. According to some embodiments of the present invention, power supply 170 is a pulsed direct current (DC) power supply, although alternating current (AC) or other types of power supplies can also be utilized. The wire 140 is fed from the filler wire feeder 150 through the contact tube 160 toward the workpiece 115 and extends beyond the tube 160. The extension of wire 140 is resistively heated so that the extension approaches or reaches the melting point before it contacts the molten pool on the workpiece. The laser beam 110 serves to melt a portion of the base metal of the workpiece 115 to form a molten pool, and can also be used to melt the wire 140 onto the workpiece 115. The power source 170 supplies energy necessary for resistance melting of the filler wire 140. As will be described in detail later, in some embodiments, the power source 170 provides all of the required energy, while in other embodiments, a laser or other high energy heat source provides a portion of the energy. You can also. According to other particular embodiments of the invention, the feeder subsystem may be capable of supplying one or more wires simultaneously. This will be described in more detail later.

  The system 100 further includes a motion control subsystem that moves the laser beam 110 (energy source) and the resistive filler wire 140 along the workpiece 115 in the same direction 125 (at least in a relative sense) to provide a laser beam. 110 and resistive filler wire 140 may remain in a fixed relationship with respect to each other. According to various embodiments, the relative motion between the workpiece 115 and the laser / wire combination can be achieved by actually moving the workpiece 115 or by moving the laser device 120 and the wire feeder subsystem. It may be realized. In FIG. 1, the motion control subsystem includes a motion controller 180 operatively connected to a robot 190. The motion controller 180 controls the motion of the robot 190. The robot 190 is operably connected to the workpiece 115 (eg, mechanically fixed) and moves the workpiece 115 in the direction 125 so that the laser beam 110 and the wire 140 are effectively moved along the workpiece 115. To. According to an alternative embodiment of the present invention, the laser device 120 and the contact tube 160 may be integrated into a single head. The head may be moved along the workpiece 115 via a motion control subsystem operatively connected to the head.

  In general, there are several ways in which a high intensity energy source / wire can be moved relative to the workpiece. For example, if the workpiece is round, the high intensity energy source / wire may be stationary and the workpiece may be rotated under the high intensity energy source / wire. Alternatively, the robot arm or linear tractor may be moved parallel to the round workpiece, while the workpiece is rotated, the high-strength energy source / wire is moved continuously or moved one step at a time. For example, the surface of a round workpiece may be piled up. If the workpiece is flat or at least not round, the workpiece may be moved under a high intensity energy source / wire as shown in FIG. However, a robot arm or linear tractor or even a beam mounting carriage may be used to move the high energy source / wire relative to the workpiece.

The system 100 further includes a sensing and current control subsystem 195 that is operatively connected to the workpiece 115 and the contact tube 160 (ie, operatively connected to the output of the power source 170) and that connects the workpiece 115 and the wire 140. The potential difference (ie voltage V) between the currents (I) passing through can be measured. The sensing and current control subsystem 195 can further calculate a resistance value (R = V / I) and / or a power value (P = V ^* I) from the measured voltage and current. In general, when the wire 140 is in contact with the workpiece 115, the potential difference between the wire 140 and the workpiece 115 is zero volts or very close to zero volts. As a result, the sensing and current control subsystem 195 can sense that the resistive filler wire 140 is in contact with the workpiece 115 and is operatively connected to the power supply 170, as will be described in more detail later herein. It is further possible to control the flow of current through the resistive filler wire 140 in response to sensing. According to other embodiments of the present invention, the sense and current controller 195 may be an integral part of the power supply 170.

  According to certain embodiments of the invention, motion controller 180 may further be operatively connected to laser power supply 130 and / or sensing and current controller 195. In this way, motion controller 180 and laser power source 130 communicate with each other so that laser power source 130 knows that workpiece 115 is moving and motion controller 180 determines whether laser device 120 is in operation. I know if it's not. Similarly, in this manner, motion controller 180 and sensing and current controller 195 may be in communication with each other so that sensing and current controller 195 knows that workpiece 115 is moving and motion controller 180 Indicates whether the filler wire feeder subsystem is in operation. Such communication may be used to coordinate operation between the various subsystems of system 100.

  As is generally known, additive manufacturing is the process of depositing material on a workpiece to create the desired product. In some applications, the molded article can be very complex. However, known methods and systems used for additive manufacturing tend to be slow and have limited performance. Embodiments of the present invention address these areas by providing high speed and high accuracy additive manufacturing methods and systems.

  The system 100 shown in FIG. 1 is an exemplary system that creates the desired shape by repeatedly melting the wire 140 into droplets and depositing them on the workpiece. This process is exemplarily shown in FIGS. As shown in these drawings. As shown in FIG. 2A, the surface of the workpiece is irradiated with a laser beam 110 (or other heat source) while the wire 140 is not in contact with the workpiece. The beam 110 forms a weld pool A on the surface of the workpiece. In most applications, the weld pool A has a small area and the extent of penetration is not as great as necessary for other operations, such as welding or joining. Rather, the weld pool A brings the surface of the workpiece into a state where it can receive and sufficiently bond with the droplets from the wire 140. Therefore, the beam density of the beam 110 is such that only a small weld pool is formed on the work piece, so that a heat input to the work piece is not too large or too large. . When the molten pool is formed, a droplet D is formed at the tip of the wire 140 while the wire is advanced to the molten pool A, and comes into contact with the molten pool A (see FIG. 2B). After the contact, the droplet D is deposited on the molten pool A and the workpiece (see FIG. 2C). This process is repeated to form the desired workpiece. An optional step is shown in FIG. 2D, in which the beam 110 is directed to the droplet D after it has been separated from the wire 140. In such an embodiment, the beam 110 can be used to smooth the surface of the workpiece and / or to allow the droplet D to be fully integrated with the workpiece. In addition, the beam can be used to further shape the workpiece.

  FIG. 3 illustrates an exemplary deposition process for droplet D from wire 140. The image at the left end of FIG. 3 depicts the wire 140 in contact with the workpiece. This contact is detected by the power source 170, which then supplies a heating current to the wire 140 to heat the wire to or near the melting point of the wire 140. The detection circuit used to detect contact between the workpiece and the wire 140 is configured and can be operated similarly to known detection circuits used in welding power sources, and therefore the operation of the circuit A detailed description of the structure is not necessary here. The heating current from the power supply 170 is ramped up very rapidly to supply the energy necessary to melt the droplet D from the end of the wire 140. However, the current is carefully controlled so that no arcing occurs between the wire 140 and the workpiece. The occurrence of an arc can prove to destroy the workpiece and is therefore undesirable. Therefore, the current is controlled in such a way as to prevent arc formation (described further below).

  Returning to FIG. 3, the wire 140 is in contact with the workpiece and the power source 170 supplies the melt current (1). In some exemplary embodiments, an open circuit voltage OCV can be applied to the wire 140 prior to contact. After contact, the current is rapidly raised to melt the end of the wire 140 to form a droplet D to be deposited (2). The electric current causes the wire 140 to be constricted immediately above the droplet D, so that the droplet D can be separated from the wire 140 (3). However, the current is cut or greatly reduced when the wire 140 is constricted so that no arcing occurs between the wire 140 and the workpiece when the wire 140 separates from the droplet D. (4). In some exemplary embodiments, the wire 140 can be retracted from the workpiece during or shortly before disconnecting the droplet D and the wire 140. Since the droplet D is in contact with the molten pool, the surface tension of the molten pool helps to separate the droplet from the wire 140. When the droplet is separated from the wire 140, the wire 140 is unwound and the process is repeated, and another droplet is deposited. The wire 140 can be paid out at the same location and / or the next droplet can be deposited at any desired location.

  As described above, the laser beam 110 can also be used to deposit the droplet D on the workpiece, smooth the workpiece after deposition, or otherwise shape the workpiece. Furthermore, the beam 110 can be further utilized during the deposition process. That is, in some exemplary embodiments, the beam 110 can be used to further heat the wire 140 to help form a droplet and / or separate the droplet D from the wire 140. This will be further described later.

  Referring now to FIGS. 4A and 4B, each illustrates an exemplary current waveform that can be utilized in an exemplary embodiment of the invention. As can be seen in FIG. 4A, the waveform 400 has a plurality of pulses 401, each pulse representing the movement of the droplet D from the wire 140. Current pulse 401 begins when wire 140 contacts. The current is then increased using the rising portion 402 to the peak current level 403, which occurs just before the separation between the wire 140 and the droplet D. In this embodiment, the current continuously increases at the rising portion 402, forming droplets and constricting the wire before separation. Prior to the separation of the droplet D, the current is rapidly reduced at the falling portion 404 to prevent arcing during separation. In waveform 400 of FIG. 4A, the current is cut and drops to zero. However, in other exemplary embodiments of the present invention, it may be unnecessary to reduce the current to a lower isolation level and completely disconnect until isolation occurs. In such an embodiment, the lower separation current level continues to heat the wire 140, thus assisting in the detachment of the droplet D.

  FIG. 4B shows a current waveform 410 according to another exemplary embodiment. However, in this embodiment, the pulse 411 has a rising portion 402, which utilizes a plurality of different ramp rate portions as shown. In the illustrated embodiment, the rising portion 402 utilizes three different ramp plates 402A, 402B, and 402C prior to droplet D separation. The first ramp rate 402A is very steep and has a rapid current increase, heating the wire 140 quickly and starting the melting process as soon as possible. After the current reaches the first level 405, the current ramp rate is changed to a second ramp rate 402B that is lower than the first ramp rate. In some exemplary embodiments, the first current level is in the range of 35-60% of the peak current level 413 of the pulse. The ramp rate 402B is lower than the initial ramp rate 402A and assists in current control and prevents arc or micro arc formation. In the illustrated embodiment, the second ramp rate is maintained until droplet D begins to form at the tip of wire 140. In the illustrated embodiment, when the droplet D begins to form, the current ramp rate is changed again to the third ramp rate 402C, which is lower than the second ramp rate 402B. Again, the ramp rate reduction provides further control of the current to prevent unintentional generation of arcs. If the current increases too quickly, it can be difficult to prevent the generation of arcs by rapidly decreasing the current when separation is detected (due to various problems such as system inductance). In some exemplary embodiments, the transition point 407 between the second and third ramp rates is in the range of 50-80% of the peak current level 413 of the pulse 411. Similar to the pulse of FIG. 4A, the current is greatly reduced when droplet separation is detected, as will be described in more detail later. It should also be noted that other embodiments of the present invention can utilize different ramp rate profiles, which do not depart from the scope and spirit of the present invention. For example, the pulse may have two different ramp rate portions, or more than two. In addition, the pulses can take advantage of constantly changing rising edges. For example, the current may draw a reverse parabola to the peak current level, or a combination of different configurations may be utilized, in which case a constant ramp rate is used from wire contact to the first current level 405, then A reverse parabolic curve can be used from that point.

  As described herein, the peak current level of pulses 401/411 is lower than the arc generation level, but is assumed to be sufficient to melt droplet D during each pulse. Exemplary embodiments of the present invention can utilize different control methods for peak current levels. In some exemplary embodiments, the peak current level can be a peak current threshold, which is determined by various user input parameters that are entered prior to additional manufacturing operations. Such parameters include the type of wire material, the wire diameter, the type of wire (whether cored or solid), and the number of droplets per inch (DPI (droplets-per-inch)). Of course, other parameters can be used. Upon receiving this input information, the power supply 170 and / or the controller 195 can determine the peak current value for the operation using various control methods such as a lookup table. Alternatively, the power source 170 can monitor the output current, voltage, and / or power from the power source 170 to determine that isolation has occurred and control the current accordingly. For example, dv / dt, di / dt, and / or dp-dt can be monitored (using a prediction circuit or others), and if it is determined that separation has occurred, the current is cut or reduced. This will be described in more detail later.

  The following is a description of the use and operation of an exemplary embodiment of the present invention. At the start of the additive manufacturing process, the power source 170 can apply a sensing voltage between the wire 140 and the workpiece 115 via the power source 170. The sense voltage may be applied by power supply 170 under the command of sense and current controller 195. In some embodiments, the applied sense voltage does not provide enough energy to heat the wire 140 significantly. When the sensing voltage is applied, the tip of the wire 140 is drawn out toward the workpiece 115. The laser 120 then emits a beam 110 to heat the surface of the workpiece 115 and form a molten pool that receives the wire 140. The feeding is performed by the wire feeder 150, and the contact with the workpiece is detected when the tip of the wire 140 first contacts the workpiece 115. For example, the controller 195 may instruct the power supply 170 to provide a very low level of current (eg, 3-5 amps) into the wire 140. Sensing may be performed by sensing and current controller 195 measuring a potential difference of about zero volts (eg, 0.4V) between wire 140 (eg, via contact tube 160) and workpiece 115. When the tip of the filler wire 140 is shorted to the workpiece 115 (ie, in contact with the workpiece), there may not be a large voltage level (greater than zero volts) between the filler wire 140 and the workpiece 115.

  After contact, in response to sensing, the power source 170 can be disconnected for a predetermined time interval (eg, several milliseconds). Then, at the end of the predetermined time interval, the power supply 170 is turned on again so that the flow of the heating current is applied to the wire 140. Also, after contact is sensed, the beam 110 can be turned off to prevent the molten pool or workpiece 115 from being heated further. In some embodiments, the laser beam 110 can be left on to assist in heating and separating the droplet D. This will be described in more detail later.

  In some exemplary embodiments of the present invention, the steps include stopping wire unwinding in response to sensing and resuming wire 140 unwinding at the end of a predetermined time interval (ie, rewinding). And confirming that the tip of the filler wire 140 is still in contact with the workpiece 115 before applying the heating current flow or after the heating current is applied and the droplet D is formed. Can be included. The sense and current controller 195 may instruct the wire feeder 150 to stop feeding and may instruct the system 100 to wait (eg, several milliseconds). In such an embodiment, the sense and current controller 195 is operatively connected to the wire feeder 150 and commands the wire feeder 150 to start and stop. The sensing and current controller 195 may instruct the power supply 170 to apply a heating current pulse to heat the wire 140 as described above, and this process may be repeated to transfer a plurality of droplets to the workpiece. Can be deposited on top.

  In operation, a high intensity energy source (eg, laser device 120) and wire 140 can be moved along workpiece 115 to provide the desired droplets. Motion controller 180 commands robot 190 to move workpiece 115 relative to laser beam 110 and wire 140. The laser power source 130 supplies power for operating the laser device 120 to form the laser beam 110. In another embodiment, the laser device 120 includes optical components that can be adjusted to change the shape of the laser beam 110 on the impact surface of the workpiece. Embodiments can utilize the shape of the beam to control the shape of the deposition process, i.e., use a rectangular, oval, or elliptical beam to perform a relatively narrow deposition. Therefore, a thinner wall structure is possible. Furthermore, the shape of the beam can be used to shape the deposit after the droplets have been separated from the deposited material.

  As described above, the pulse current is cut or greatly reduced when it is determined that the wire 140 and the droplet D are about to be separated soon. This can be achieved in various ways. For example, such sensing may involve sensing and predicting circuitry in current controller 195 where the potential difference (dv / dt) between wire 140 and workpiece 115, the current through them (di / dt), the resistance between them ( It may be realized by measuring the rate of change of one of dr / dt) or the power passing through them (dp / dt). When the rate of change exceeds a predetermined number, the sense and current controller 195 formally predicts that contact loss is likely to occur. Such prediction circuits are well known in the arc welding industry and a detailed description of their structure and function is not necessary here.

  When the tip of the wire 140 is sufficiently melted by heating, the tip starts to be constricted from the wire 140 to the workpiece 115. For example, at that point, the potential difference or voltage increases because the cross-sectional area of the tip of the wire rapidly decreases as it narrows. Thus, by measuring such a rate of change, the system 100 can predict that the tip will soon be constricted and contact with the workpiece 115 will be lost.

  As previously described, when droplet separation is sensed, the current can be cut off or greatly reduced by the power source 170. For example, in some exemplary embodiments, the current is reduced to be in the range of 95-85% of the peak current value of the pulse. In the exemplary embodiment, this current reduction occurs before the separation between the wire and the weld pool.

  For example, FIG. 5 shows a pair of voltage and current waveforms, 510 and 520, respectively, in connection with the additive manufacturing process of the present application. The voltage waveform 510 is measured by the sensing and current controller 195 between the contact tube 160 and the workpiece 115. Current waveform 520 is measured in wire 140 and workpiece 115 by sensing and current controller 195.

  Each time the tip of the wire 140 is about to lose contact with the workpiece 115, the rate of change of the voltage waveform 510 (ie, dv / dt) exceeds a predetermined threshold, indicating that constriction will soon occur (waveform (See slope at 510, point 511). Alternatively, the rate of change of current through wire 140 and workpiece 115 (di / dt), the rate of change of resistance between them (dr / dt), or the rate of change of power through them (dp / dt) instead May be used to indicate that the constriction is about to occur. Such a prediction method based on the rate of change is well known in the art. At that point, the sensing and current controller 195 instructs the power supply 170 to cut (or at least significantly reduce) the flow of current through the wire 140.

  When the sense and current controller 195 senses that the tip of the filler wire 140 is again in full contact with the workpiece 115 after a certain time interval 530 (eg, the voltage level drops again to about zero volts at point 512), the sense and current Controller 195 commands power supply 170 to cause the current flow through resistive filler wire 140 to rise to a predetermined output current level 550. The time interval 530 can be a predetermined time interval. In one embodiment of the invention, the rise begins at a fixed point value 540. This process is repeated while the energy source 120 and the wire 140 are moving with respect to the workpiece 115 and as the wire 140 is unwound toward the workpiece 115 by the wire feeder 150 so that a plurality of droplets can be formed as desired. Accumulate in position. In this way, arc formation between the tip of the wire 140 and the workpiece 115 is prevented. The rise of the heating current helps to prevent the rate of voltage change from being interpreted unexpectedly when there are no constricted or arc conditions. Large current changes may cause false voltage readings due to inductance in the heating circuit. When the current rises gradually, the influence of inductance decreases.

  As described above, the power source 170 supplies a heating current to the filler wire 140. Current passes from contact tip 160 to wire 140 and then to the workpiece. This resistance heating current reaches a temperature at or near the melting point of the filler wire 140 where the wire 140 between the tip 160 and the workpiece is used. Of course, the heat required to reach the melting point of the filler wire 140 depends on the size and nature of the wire 140. Thus, the heat to reach the desired temperature of the wire during manufacture varies from wire 140 to wire 140. As described further below, the desired operating temperature of the filler wire can be used as a data input to the system so that the desired wire temperature is maintained during manufacturing. In any case, the temperature of the wire should be such that the wire 140 can deposit droplets in the molten pool.

  In an exemplary embodiment of the invention, the power source 170 supplies current, which causes at least a portion of the tip of the wire 140 to be at a temperature of about 90% or higher of its melting point. For example, when using a filler wire 140 with a melting point of about 2,000 ° F., the temperature of the wire when it contacts can be about 1,800 ° F. Of course, it will be appreciated that the respective melting point and desired operating temperature will depend at least on the filler wire 140 alloy, composition, diameter, and feed rate. In another exemplary embodiment, a portion of the wire is held at the temperature of the wire, which is 95% or higher of its melting point. Of course, in some embodiments, the wire tip is heated to at least 99% of its melting point by a heating current. Therefore, when the heated droplet contacts the molten pool formed by the laser, the heat from the molten pool further heats the wire 140 to sufficiently form a molten droplet at the end of the wire 140, and the wire 140 When pulled back, the droplets adhere to the molten pool so that they remain there. By holding the filler wire 140 at or near its melting point, the wire 140 is easily melted or taken into the molten pool formed by the heat source / laser 120. That is, the wire 140 is at a temperature that does not significantly quench the molten pool when the wire 140 contacts the molten pool. Since the wire 140 is hot, the wire melts quickly when it comes into contact with the molten pool. In other exemplary embodiments, the wire can be heated to 75% of its melting point or higher. However, when heated to a temperature close to 75%, further heating may be necessary to bring the droplets into a molten state sufficient for movement, which will be further described later.

  As described above, in some exemplary embodiments, complete melting of the wire 140 can only be facilitated by allowing the wire 140 to enter the molten pool. However, in other exemplary embodiments, the wire 140 can be completely melted by a combination of a heating current, a molten pool, and a laser beam 110 that impinges on a portion of the wire 140. That is, the laser beam 110 is used for heating / melting the wire 140, and the beam 110 contributes to the heating of the wire 140. However, since many filler wires 140 are made of a reflective material, when a reflective laser type is used, the wire 140 is heated to a certain temperature to reduce its surface reflection and the beam 110 is heated / heated to the wire 140. Should be able to contribute to melting. In an exemplary embodiment of this configuration, wire 140 and beam 110 intersect at the point where wire 140 enters the molten pool. This is illustrated in FIGS. 6A and 6B.

  As shown in FIG. 6A, in some exemplary embodiments, beam 110 can be used to help deposit droplet D on workpiece 115. That is, the beam 110 can be used to further heat the tip of the wire 140 and generate molten droplets. In such an embodiment, the heating current from the power source can be kept at a level well below the arc generation level, thus ensuring that no arc is generated and proper droplet movement can be achieved. In such embodiments, the beam can be directed so that it impinges only on droplet D, or in other embodiments, beam 110 can be directed to at least a portion of the droplet and the molten pool. The molten pool continues to be heated further by impacting at least a portion and is made large enough to receive the droplet D, shaped in such a way, or irradiated in a raster fashion in such a way. In the exemplary embodiment, the energy density of beam 110 at this stage in the process is generally lower than the energy density of the beam when used to form a weld pool on workpiece 115.

  FIG. 6B illustrates another exemplary embodiment of the present invention, in which the beam 110 impinges on the wire 140 just above the droplet and helps it separate from the wire. In such an embodiment, when the wire 140 is sensed or determined to be constricted on the droplet, the beam 110 is directed to the connection between the droplet D and the wire 140 of the wire, A beam 110 helps to separate these two. Such an embodiment helps prevent arc generation because it is not necessary to use a heating current to control the separation. In some exemplary embodiments, beam 110 may be emitted from the same laser 120 that was used to initially create the weld pool. However, in other embodiments, the beam of FIG. 6B may also be emitted from a second separate laser, which is also controlled by the controller 195. Thus, in such an embodiment, if the controller and / or power source detects that a droplet has formed or droplet D is about to separate, the output current of power source 170 can be reduced while the laser beam Is directed to the wire 140 and separated as desired.

  Referring now to FIG. 7, an exemplary embodiment of a heating system 700 and contact tip assembly 707 is shown. In general, embodiments of the present invention may utilize a contact tip 160 and a resistance heating system well known for hot wires or certain welding systems, which also does not depart from the spirit or scope of the present invention. To do. However, in other exemplary embodiments, the system 700 shown in FIG. 7 can be used. In this system 700, the contact tip assembly consists of two conductive portions 701 and 703, which are electrically isolated from each other by an insulating portion 705, which can be made of either dielectric material. Of course, in other embodiments, as long as the chip portions 701 and 703 are electrically isolated from each other, there may be no insulating portions. The system 700 also includes a switching circuit 710 that switches the current path to / from the power supply 170 between the contact tip portion 701 and the workpiece 115. In some embodiments, it may be desirable to maintain the wire 140 at a certain threshold temperature during the manufacturing process while the wire 140 is not in contact with the workpiece 115. If the wire 140 is not in contact with the workpiece 115 (eg, during a position change), no current will flow through the wire 140, so resistance heating stops. Of course, residual heat is still present, but can be quickly reduced. According to this embodiment, the wire 140 continues to be heated even if it is not in contact with the workpiece 115. As shown, one lead from the power source is coupled to the upper portion 703 of the contact chip assembly 707. In operation, when the wire 140 is in contact with the workpiece, the switch 710 is positioned so that the current path passes from the upper portion 703 through the wire 140 and the workpiece and back to the power source 170 (dashed line in the switch 710). . However, when the droplet D is separated from the wire 140 and disconnected from the workpiece 115, the switch 710 is switched so that the current reaches the contact tip portion 701 from the contact tip portion 703 and returns to the power source 170. This allows at least a portion of the heating current to pass through the wire and subsequently resistively heat the wire to some background heating level. With such a configuration, the wire can be heated more quickly to its desired deposition level. This is especially true when the period between droplet depositions is long, where the wire can cool. Thus, in the exemplary embodiment, when switch 710 is in a first position (first current path) that directs current through the work piece, power supply 170 causes a current pulse (s). (As generally described herein) and then the switch passes through both portions 701/703 of the contact tip and current to keep the wire heated between each droplet transfer Is in the second position (second current path), the power supply 170 supplies background or heating current (which can be, for example, a constant current). In some embodiments, the switch can be switched between each droplet transfer pulse, and in other embodiments, the switch can be switched after multiple droplet transfer pulses. In an exemplary embodiment, the background / heating current level is selected to be a level that maintains the wire at a desired, non-melting temperature. If the temperature is too high, it can be difficult to push the wire into the molten pool. In some exemplary embodiments, the background / heating current is in the range of 10-70% of the peak current level reached during the droplet transfer pulse.

  Note that in FIG. 7, switch 710 is shown outside power supply 170. However, this figure is for clarity only and the switch may be in the power source 170. Alternatively, the switch may also be in the contact tip assembly 707. Insulating portion 705 can be made of any type of insulating material or simply an insulating gap between components 701 and 703. The switch can be controlled by the controller 195 (as shown) or directly by the power supply 170, depending on the desired configuration.

  In other exemplary embodiments, a wire preheater can be positioned upstream of the assembly 707, which preheats the wire 140 before it enters the tip 707. For example, the preheating device can be an induction heating device, which does not require a current through the wire 140 to heat the wire 140. Of course, resistance heating systems can also be used. This preheating device can be used to keep the wire at a certain temperature, as described above. In addition, preheating can also be used to remove all of the unwanted moisture from the wire 140 before it is deposited (this is particularly important when using Ti). Such preheating systems are generally known and do not require detailed description. The preheater can be set to heat the wire 140 to a predetermined temperature before the wire enters the chip assembly 707, and therefore provides sufficient current to complete the deposition process using the current from the power source 170. it can. It should be noted that the preheater should heat the wire 140 to a level that will damage the wire 140 so that the wire 140 can be properly pushed through the tip 707. That is, if the wire 140 is too hot, it can become overly flexible, thereby reducing the responsiveness of the wire 140 when being pushed forward.

  FIG. 8A shows an exemplary manufacturing current waveform 800 that can be used in the system 700 of FIG. In FIG. 8A, a basic current waveform 800 is shown that includes two components: a pulse portion 801 and a background portion 803. The pulse portion consists of a current pulse that is used to deposit droplets as described herein. During these pulses, current is directed from the tip portion 703 through the workpiece 115. However, in the background portion, current is directed from tip portion 703 to portion 701 to heat wire 140 when it is not in contact with workpiece 115. Of course, it should be noted that the contact tip portions 701/703, as shown in FIG. 7, are examples connected to the positive and negative power supply terminals, and the connection depends on the desired system setup and performance. Can be reversed on the basis. As described above, the background current level 803 between pulses 801 is used to keep the wire at a sustained temperature between each droplet deposition. In some exemplary embodiments of the invention, the background current keeps the wire 140 at a temperature in the range of 40-90% of the melting point of the wire 140. In other exemplary embodiments, the current 803 keeps the wire 140 at a temperature in the range of 50-80% of the melting point of the wire 140.

  Furthermore, note that it may not be desirable or necessary to always switch to background current between each pulse 801. This is especially true during high speed droplet deposition. That is, during high speed droplet deposition, the wire 140 is held at a high temperature level between droplets. Therefore, in some exemplary embodiments, switching the background heating current (as described above) is performed only after a period of time has elapsed or when the period between droplet pulses exceeds the time threshold. Is called. For example, in some embodiments, if the time between pulses will exceed 1 s, the system 700 uses switching and background heating current as described above. That is, when the manufacturing method employed has a pulse frequency higher than a predetermined threshold frequency, the above switching is used. In an exemplary embodiment of the invention, this threshold is in the range of 0.5 to 2.5 s between pulses. In other embodiments, the system 700 can utilize a timer (which is internal to the controller 195 and / or power supply 170) that monitors the time between pulses and switches the above-described switching if the time exceeds a threshold amount. And background heating current is utilized. For example, if the system 700 determines that the latency between pulses exceeds a threshold time limit (eg, 1 s), a background heating current is utilized to hold the wire at a predetermined temperature. Such an embodiment may be utilized in embodiments where a set threshold time has elapsed, i.e., in real time, the system 700 determines that the time limit has elapsed, or the system 700 may It may be used when it is predicted that it will not occur before the time limit has passed. For example, if system 700 (eg, controller 195) determines that the next pulse will not occur before the time limit elapses (eg, due to movement of workpiece 115 and / or wire 140), system 700 may The switching and background heating currents described above can be started immediately. In an exemplary embodiment of the invention, this duration threshold is in the range of 0.5 to 2.5 seconds.

  FIG. 8B illustrates an exemplary waveform that can be used in an exemplary embodiment of the present invention to deposit droplets as described herein. The exemplary waveform relates to the movement of one droplet according to an embodiment of the present invention. The waveforms in the figure relate to laser output 810, wire feed rate 820, additional wire heating current 830, and voltage 840. It should be understood that the waveforms in the figure are for illustrative purposes, and other embodiments of the present invention are other waveforms that have different characteristics than those shown or described herein. Can also be used. As shown, the droplet transfer cycle begins at 811 where the laser power is directed to the workpiece and raised to a peak laser power level 813 (812). After a duration Tp, the laser forms a molten pool on the workpiece at point 814. At this point, the wire feeder starts driving the additional wire toward the molten pool. After the weld pool is formed at 814, the wire feed rate increases to the peak wire feed rate 822 (821). In an exemplary embodiment of the invention, the wire feed rate reaches its peak level 822 at approximately the same time as the wire tip contacts the molten pool (821 '). However, in other exemplary embodiments, the wire feed rate can reach its peak level 822 before the wire contacts. As shown, simultaneously with the beginning of the wire feeding process, an open voltage is applied to the wire (841), which reaches a peak voltage level 842 at some point before the wire contacts the molten pool. Also, when the wire comes into contact with the molten pool, the heating current 830 begins to flow (at point 831) and the voltage 840 begins to decrease (843). The voltage drops to a level 844 that is lower than the arc detection voltage 848 above which it is determined that an arc has been generated.

  After the wire comes into contact with the molten pool, the laser power 810, the wire feed rate 820, and the current 830 are held at their respective peak levels for a period of time Ta, during which time droplets of the wire accumulate in the molten pool. When the deposition period Ta, which can be a predetermined period controlled by the heating power source (at 815) elapses (eg, using a timer circuit), the laser output falls with the fall of the wire feed rate (823) ( 816). The heating current 830 is held at its peak level 833 for a period of time after the lapse of the period Ta (upper point 834), during which the laser power and wire feed rate decrease. This helps to separate the droplet from the wire. After the droplet addition period Ta, the wire pull-back period Tr starts. When current 830 begins its fall 835 (starting at point 834), the wire feed rate drops to zero (at point 827) and the wire feeder is controlled to pull back the wire at the peak retraction rate 825 (824). . Also, during the pullback period, the current 830 drops to a burnback current level 836, which is used to provide wire burnback as it is drawn from the molten pool. During the wire pullback period Tr, the current 830 causes the voltage to reach or pass the arc detection voltage level 848 at point 845 due to the wire being separated from the weld pool (which reduces the current and increases the voltage). Until then, the burnback current level 836 is maintained. When voltage level 848 is reached, arc suppression routine 847 begins and arc generation is prevented. During this period, the voltage rises to the peak level 846.

  Arc detection voltage level 848 is a predetermined level used by the power supply and / or system controller to ensure that no arcing occurs between the retracting wire and the workpiece. The arc detection voltage level 848 is set by the power supply and / or system controller based on various user inputs, including input of wire type, wire diameter, workpiece material type, number of droplets per inch. This includes, but is not limited to, entering the number of droplets per minute.

  When the arc detection voltage level 848 is reached (at 845), the current 830 is cut by the power source (837), the wire withdrawal is stopped (826), and the droplet transfer cycle is terminated at point 817, at which time the current 830 and The wire feeding speed 820 is 0 respectively. In the illustrated embodiment, laser power 810 is also shown to be disconnected at the end of the cycle at point 817. In another exemplary embodiment, the laser output 810 is disconnected when the arc voltage threshold 848 is reached (at point 845). This cycle is then repeated for multiple droplet depositions.

  In some exemplary embodiments, a laser output pulse (not shown) is initiated between each droplet transfer cycle (shown in FIG. 8B) to smooth the workpiece between each droplet transfer, or Besides that, it can help to add energy to the work piece. For example, a laser output pulse can be initiated between each droplet transfer cycle, or in other embodiments, a laser output pulse can be started after n droplet transfer cycles as needed.

  FIG. 9 illustrates another exemplary system 900 of the present invention. System 900 includes a background power supply 170 ′ and a pulse power supply 170. This system operates in a manner very similar to that described above, with the exception that background heating current is supplied by another power source 170 '. Thus, in some embodiments, the background power supply 170 'can provide a constant heating current during manufacture and need not provide the switching described above. The pulsed power supply 170 operates as described elsewhere in this specification, with the exception that additional heating / current is provided by the power supply 170 ', thus reducing the peak output current. . In such an embodiment, the control or precision level when using the pulse power supply 170 can be improved. In other words, the pulse power supply 170 can reach the peak pulse level at a higher speed because the demand for current to the power supply 170 becomes smaller. Of course, the same is true for the current drop. Each of the power supplies 170/170 'may be controlled by a controller 195 or configured in a generally known master / slave relationship. Further, although these power supplies are shown separately for clarity, they can also be stored in a single unit, which also does not depart from the spirit or scope of the present invention.

  Also shown in FIG. 9 is another contact tip assembly 900 having conductive portions 901 and 905 and an insulating portion 903. In this embodiment, the conductive portion 905 is configured so that the heating current is transmitted as close as possible to the exposed tip of the wire 140. Such a configuration helps to ensure that the heating of the wire is held as close as possible to the tip and that the effect of background heating is optimized. In another embodiment, the protrusion X at the tip of the wire 140 from the contact tip 910 is kept at a minimum distance. If the protrusion X is held too long, the heating effect from the background heating current may adversely affect it. Therefore, in some exemplary embodiments, the protrusion X is held in the range of 0.1 to 0.5 inches. In other exemplary embodiments, the protrusions are held in the range of 0.2 to 0.4 inches. Furthermore, in another exemplary embodiment, to further benefit from background heating, the wire 140 is pulled completely or nearly completely back into the contact tip 910 between droplet pulses, and the protrusion X is zero. Be in the range of ~ 0.15 inches. Such an embodiment may keep the tip of the wire 140 at a desired background heating temperature and avoid overheating other portions of the wire 140 that are not near the tip. In other exemplary embodiments, the protrusion distance can be longer, especially when using larger diameter weld materials. For example, in some exemplary embodiments, the protrusion distance can be in the range of 0.75 to 2 inches. Of course, in some other embodiments, longer protrusions can be utilized.

  Referring now to FIG. 10, another exemplary system 1000 is depicted in which the contact tip assembly 1010 can supply a plurality of wires 140/140 'to the workpiece 115. In some additive manufacturing operations, it may be desirable to utilize different wires for different parts of the manufacturing. The system 1000 can switch between different wires depending on what is desired for its manufacture. Although not shown, each wire 140/140 'can be coupled to a respective wire feeder so that the respective wire 140/140' can be unwound or pulled back as needed during manufacture. Thus, during manufacturing, the controller 195 can position the contact tip assembly 1010 such that the appropriate wire is used in manufacturing. For example, build a foundation with a first weld material 140 having a first characteristic, and then add to that foundation a layer made of wires 140 'having different characteristics to achieve the desired manufacturing result It may be desirable to do. For example, the wires 140/140 'can have different sizes, shapes, and / or compositions based on the desired manufacturing parameters. Although the contact tip assembly is shown with only two wires 140/140 ′, embodiments of the present invention may include a single contact tip assembly or separate contact tips to provide various types of welding materials. It should also be noted that it can be used. Embodiments of the present invention are not limited in this respect.

  Further, the contact tip assembly 1010 of FIG. 10 is shown such that the wires 140/140 'are not insulated from each other. In such an embodiment, a suitable wire is routed toward the workpiece 115 for deposition so that current from the power source 170 is directed into the wire and deposited. As the wire is changed, the other wire is unwound while the other is pulled back, this time through the current path through the other wire. In other exemplary embodiments, contact tip assembly 1010 can be configured such that wires 140/140 'are electrically isolated from each other. In such an embodiment, switching as described with respect to FIG. 7 may be utilized. In some exemplary embodiments, does the laser beam (not shown in FIG. 10) affect the energy distribution in the weld pool by scanning between the two wires 140 and 140 ′? Other than that, it can be changed.

  The positioning and movement of the contact tip assembly 1010 relative to the workpiece 115 can also be performed by various means. In particular, any known robot or motion control system can be used, which does not depart from the spirit or scope of the present invention. That is, the appropriate wire 140/140 'can be positioned and controlled by the controller 195 using any known means or method, including robotic systems. For example, the contact tip assembly 1010 can include three or more different wires, as well as known computer numerical control (CNC) machining heads that are rotated and positioned to utilize appropriate tooling. Configure and use. Such systems and control logic can be used in embodiments of the present invention to provide the desired positioning of the desired wires.

  The wire (ie, the welding material) used in the embodiments of the present invention will have the size and properties necessary for a particular manufacturing operation. Generally, the wire has a circular cross section, but in other embodiments it is not so limited. Other exemplary embodiments can utilize a wire having a non-circular cross-section based on the manufacturing method and manufacturing process. For example, the wire can have a polygonal shape, an elliptical shape, or an oval shape to achieve a desired manufacturing standard. The circular cross-section wire can have a diameter in the range of 0.010 to 0.045 inches. Of course, a larger range (eg, 5 mm maximum) can be used if desired, but droplet control becomes more difficult as the diameter increases. Through the use of the laser and heating control scheme described herein, embodiments of the present invention can provide very precise manufacturing. This is especially true for embodiments that utilize smaller diameter wires, such as those in the range of 0.010 to 0.020 inches. By using such a small diameter, a large DPI (Droplets Per Inch) ratio can be realized, thus providing high-precision detailed manufacturing. The nature of the wire will be selected to provide the desired properties for the component being manufactured. Furthermore, the wires utilized may be either solid or metal core type. The cored wire can be used to make a composite structure. For example, a cored wire having an aluminum jacket and an aluminum oxide core can be used.

  Further, since no arc is used in the processes described herein, no type of shielding gas is required in most applications of the present invention. However, in some applications it may be desirable to use a shielding gas for oxidation prevention or for other purposes.

  FIG. 11 illustrates yet another exemplary embodiment of the present invention. FIG. 11 shows an embodiment similar to that shown in FIG. However, specific components and connections are not drawn for clarity. FIG. 11 shows a system 1100 in which a thermal sensor 1110 is utilized to monitor the temperature of the wire 140. The thermal sensor 1110 can be of any known type that can detect the temperature of the wire 140. Sensor 1110 may be in contact with wire 140 or coupled to chip 160 to detect the temperature of the wire. In another exemplary embodiment of the present invention, sensor 1110 is of the type that uses a laser or infrared beam that can detect the temperature of the diameter of a small object, such as a filler wire, without contacting wire 140. In such an embodiment, the sensor 1110 is positioned so that the temperature of the wire 140 can be detected at some point between the protrusion of the wire 140, ie, the tip of the chip 160 and the molten pool. Sensor 1110 should also be positioned so that sensor 1110 for wire 140 does not detect the temperature of the weld pool.

  The sensor 1110 is coupled to a detection and control unit 195 (described with respect to FIG. 1), thereby providing temperature feedback information to the power supply 170 and / or the laser power supply 130 so that the control of the system 1100 can be optimized. It becomes possible. For example, the power or current output of the power supply 170 can be adjusted based at least on feedback from the sensor 1110. That is, in certain embodiments of the present invention, a user can enter a desired temperature setting (for certain manufacturing operations and / or wires 140) or the sensing and control unit 195 can receive other user input data ( The desired temperature can be set based on the electrode type, etc., and then the sensing and control unit 195 can control at least the power supply 170 to maintain that desired temperature.

  In such an embodiment, it is possible to account for the heating of the wire 140 that may be caused by the laser beam 110 impinging on the wire 140 before the wire enters the molten pool. In an embodiment of the present invention, the temperature of the wire 140 can only be controlled via the power source 170 by controlling the current in the wire 140. However, as described above, in other embodiments, at least a portion of the heating of the wire 140 is derived from the laser beam 110 impinging on at least a portion of the wire 140. Therefore, the temperature of the wire 140 may not be represented only by the current or power from the power source 170. Thus, the use of sensor 1110 can help control the temperature of wire 140 through control of power supply 170 and / or laser power supply 130.

  In other embodiments (also shown in FIG. 11), the temperature sensor 1120 is directed to sense the temperature of the molten pool. In this embodiment, the molten pool temperature is also coupled to a sensing and control unit 195. However, in other exemplary embodiments, sensor 1120 can be directly coupled to laser power supply 130. Feedback from sensor 1120 is used to control the output from laser power supply 130 / laser 120. That is, by adjusting the energy density of the laser beam 110, a desired molten pool temperature can be reliably realized.

  In yet another exemplary embodiment of the present invention, rather than directing the sensor 1120 to the molten pool, it can be directed to a region of the workpiece 115 adjacent to the molten pool. In particular, it may be desirable to ensure that the heat input of the workpiece 115 to the vicinity of the deposition position is minimal. The sensor 1120 can be positioned to monitor this temperature sensitive region so that the threshold temperature is not exceeded near the deposition location. For example, the sensor 1120 can monitor the temperature of the workpiece and reduce the energy density of the beam 110 based on the detected temperature. Such a configuration will ensure that the heat input near the deposition location does not exceed the desired threshold. Such an embodiment can be used in precision manufacturing operations where heat input to the workpiece is important.

  In another exemplary embodiment of the invention, the sensing and control unit 195 is coupled to a feed force detection unit (not shown) that is coupled to a wire feed mechanism (not shown—but see 150 in FIG. 1). it can. The feed force detection unit is known and detects the feed force applied to the wire 140 as it is fed to the workpiece 115. For example, such a detection unit can monitor parameters applied to the torque applied by the wire feed motor in the wire feeder 150 and hence the contact between the tip of the wire 140 and the workpiece 115. This can be coupled to a current and / or voltage monitor and can be used to stop the delivery of the wire after contact with the molten pool and allow the separation of the droplet D. Of course, as described above, the controller 195 can use voltage and / or current sensing only to detect contact between the wire 140 and the weld pool, and this information alone can be used to deliver the wire as desired upon contact. Can be stopped.

  In another exemplary embodiment, sensor 1120 can be used to detect the size of the molten pool on the workpiece. In such embodiments, sensor 1120 can be used to monitor the weld pool edge and monitor the size and / or position of the weld pool, either with a heating sensor or a visual sensor. Controller 195 then controls the operation of the system as described above using the detected information about the molten pool.

  The following further describes control of the heating pulse current that can be used in various embodiments of the present invention. As described above, when the tip of the wire 140 contacts the weld pool / workpiece 115, the voltage between the two can be at or near zero volts. However, in other exemplary embodiments of the invention, it is possible to provide a level of current that can be at a voltage level higher than 0 volts without forming an arc. By utilizing higher current values, it is possible to cause the wire 140 to reach a higher temperature near the melting point of the electrode faster. Thereby, a manufacturing process can be advanced at higher speed. In an exemplary embodiment of the invention, the power supply 170 monitors the voltage and when the voltage reaches or approaches a voltage value at any point above 0 volts, the power supply 170 stops flowing current to the wire 140. , So that no arc is formed. The voltage threshold level generally depends, at least in part, on the type of wire 140 being used. For example, in some exemplary embodiments of the invention, the threshold voltage level is 6 volts or less. In other exemplary embodiments, the threshold level is 9 volts or less. In another exemplary embodiment, the threshold level is 14 volts or less, and in another exemplary embodiment, the threshold level is 16 volts or less. For example, when using mild steel wire, the threshold level of voltage is of the lower type, and wires intended for stainless steel production can handle higher voltages before the arc is formed. Therefore, such a system can control the heating current by monitoring the voltage and comparing the voltage to the voltage set point, thereby predicting that the voltage exceeds or exceeds the voltage set point. And the current is cut or reduced.

  In another exemplary embodiment, as described above, the voltage is held in the operating range rather than holding the voltage level below a threshold. In such an embodiment, a certain voltage is used to keep the voltage above the minimum value, i.e., to ensure a sufficiently high current to hold the wire at or near its melting point and to avoid arcing. It is desirable to keep it below the level. For example, the voltage can be held in the range of 1-16 volts. In another exemplary embodiment, the voltage is held in the range of 6-9 volts. In other examples, the voltage can be held between 12-16 volts. Of course, the desired operating range may be affected by the wires 140 used in the manufacturing operation, so that the range (or threshold) used for a certain operation is used at least in part. Selected based on the characteristics of the wire to be used or used. In using such a range, the lower limit of the range is set to a voltage that allows the wire to be sufficiently deposited in the molten pool, and the upper limit of the range is set to a voltage that avoids arc generation. The

  As described above, when the voltage exceeds the desired threshold voltage, the heating current is cut by the power source 170 and no arc is generated. Thus, in such an embodiment, the current can be driven based on a predetermined or selected rise rate (s) until a voltage threshold is reached, after which the voltage prevents arcing. To be cut or reduced.

  In many of the embodiments described above, the power supply 170 includes circuitry utilized to monitor and maintain the voltage as described above. Such types of circuit configurations are known to those skilled in the art. Conventionally, however, such circuits are utilized to maintain the voltage above a certain threshold for arc welding.

  As described above, the heating current can also be monitored and / or adjusted by the power supply 170. This can alternatively be done in addition to monitoring certain levels of voltage, power, or voltage / amperage characteristics. That is, the current is driven to or maintained at a desired level to ensure that the wire 140 is properly deposited in the weld pool and at a temperature below the arc forming current level. it can. For example, in such embodiments, the voltage and / or current is monitored to ensure that either or both are within a specified range or below a desired threshold. The power source 170 then adjusts the supplied current so that no arc is generated and the desired operating parameters are maintained.

  In yet another exemplary embodiment of the present invention, the heating power (V × I) can also be monitored and adjusted by the power supply 170. Specifically, in such an embodiment, the voltage and current for the heating power is monitored and held at a desired level or range. Thus, the power supply can not only adjust the voltage or current to the wire, but can adjust both current and voltage. In such embodiments, the heating power to the wire can be set to an upper threshold level or an optimal operating range, so that the power is below the threshold level or within a desired range (with respect to voltage). As described above). Again, the threshold or range setting can be based on the characteristics of the wire and the manufacturing being performed, and at least in part on the selected filler wire. For example, an optimal power setting for a 0.045 "diameter mild steel electrode may be determined to be in the range of 1,950-2,050 watts. The power supply adjusts the voltage and current so that power is driven to this operating range. Similarly, if the output threshold is set to 2,000 watts, the power supply will adjust the voltage and current so that the power level does not exceed this threshold but is close to it.

  In another exemplary embodiment of the present invention, power supply 170 includes circuitry that monitors the rate of change of heating voltage (dv / dt), current (di / dt), and / or power (dp / dt). Such a circuit is often called a prediction circuit, and its general configuration is known. In such an embodiment, the rate of change of voltage, current and / or power is monitored and the heating current to wire 140 is cut when the rate of change exceeds a certain threshold.

  In other exemplary implementations of the invention, changes in resistance (dr / dt) are also monitored. In such an embodiment, the resistance between the contact tip in the wire and the molten pool is monitored. As previously mentioned, when a wire is heated, it begins to constrict, which can cause a tendency to form an arc, during which time the resistance in the wire increases in order. When this increase is detected, the output of the power source is cut as described herein and no arc is generated. Embodiments adjust the voltage, current, or both to ensure that the resistance in the wire is held at the desired level.

  FIG. 12 shows an exemplary system 1200 that can be used to supply heating current to the wire 140. (It should be noted that the laser system is not shown for the sake of clarity.) System 1200 includes a power supply 1210 (which can be of a type similar to that shown as 170 in FIG. 1). Shown to have. The power source 1210 can be a known welding / heating power source configuration, such as an inverter type power source. The design, operation and configuration of such power supplies are known and will not be described in detail herein. The power supply 1210 includes a user input 1220 that allows the user to enter data, including the type of wire, wire diameter, desired power level, desired wire temperature, voltage and / or current level. However, it is not limited to these. Of course, other input parameters can be used as required. User interface 1220 is coupled to CPU / controller 1230, which receives input data from the user and uses this information to determine the operational set points or ranges required for power module 1250. The power module 1250 can be of any known type or configuration, including an inverter or transformer type module. Note that some of these components, such as user input 1220, may also be on the controller 195.

  The CPU / controller 1230 can determine the desired operating parameters in a variety of ways, including a look-up table. In such an embodiment, the CPU / controller 1230 utilizes input data, eg, wire diameter and wire type, to produce the desired current level for output (to properly heat the wire 140) and threshold voltage or power. Determine the level (or acceptable operating range of voltage or power). This is because the current required to heat the wire 140 to the appropriate temperature is based at least on the input parameters. That is, the aluminum wire 140 may have a lower melting point than the mild steel electrode, and therefore less current / power is required to melt the wire 140. In addition, the smaller diameter wire 140 requires less current / power than the larger diameter wire. Also, as the production rate (and hence the deposition rate) increases, the current / power level required to melt the wire may increase.

  Similarly, input data is used by CPU / controller 1230 to determine voltage / power thresholds and / or ranges of operation (eg, power, current, and / or voltage) such that arc generation is avoided. Is done. For example, the voltage range setting for a 0.045 inch diameter mild steel electrode can be 6-9 volts, and the power module 1250 is driven to hold the voltage at 6-9 volts. In such embodiments, the current, voltage, and / or power is held at a minimum of 6 volts to ensure that the current / power is high enough to properly heat the electrode, and the voltage is 9 volts or less. It is held so that no arc is generated reliably and the melting point of the wire 140 is not exceeded. Of course, other set point parameters, such as voltage, current, power, or resistivity change, can also be set by the CPU / controller 1230 as desired.

  As shown, the positive terminal 1221 of the power source 1210 is coupled to the system contact chip 160 and the negative terminal of the power source is coupled to the workpiece W. Thus, the heating current is supplied to wire 140 through positive terminal 1221 and returns through negative terminal 1222. Such a configuration is generally known.

  Feedback sensing lead 1223 is also coupled to power supply 1210. The feedback sensing lead can monitor the voltage and provide the detected voltage to the voltage detection circuit 1240. The voltage detection circuit 1240 communicates the detected voltage and / or detected voltage change rate to the CPU / controller 1230, which controls the module 1250 accordingly. For example, if the detected voltage is lower than the desired operating range, the CPU / controller 1230 sends the output (current, voltage, and / or power) to the module 1250 until the detected voltage is within the desired operating range. Instruct to increase. Similarly, if the detected voltage is at or above the desired threshold, the CPU / controller 1230 instructs the module 1250 to cut off current flow to the chip 160 and not generate an arc. When the voltage drops below the desired threshold, the CPU / controller 1230 instructs the module 1250 to supply current and / or voltage to continue the manufacturing process. Of course, the CPU / controller 1230 can also instruct the module 1250 to maintain or supply the desired power level. Of course, a similar current detection circuit can be utilized, but is not shown for clarity. Such a detection circuit is generally known.

  The detection circuit 1240 and the CPU / controller 1230 can have the same configuration and operation as the controller 195 shown in FIG. In an exemplary embodiment of the invention, the sampling / detection rate is at least 10 KHz. In other exemplary embodiments, the detection / sampling rate is in the range of 100-200 KHz.

  In each of FIGS. 1 and 11, laser power supply 130, power supply 170, and sensing and control unit 195 are shown separately for clarity. However, in an embodiment of the invention, these components can be integrated into a single system. In aspects of the invention, the components individually described above need not be held as separate physical units or freestanding structures.

  In some exemplary embodiments described above, the system can be used in a manner that combines cladding and droplet deposition as described above. That is, it is not always necessary to have a highly precise configuration during the construction of the workpiece, such as during the production of a support base. A hot wire cladding process can be used during this configuration phase. Such a process (and system) is described in Patent Document 1, and the entire text thereof is incorporated herein by reference. More specifically, the application describes a system, method of use, control method, etc. that is used to deposit material using a hot wire system in cladding or other types of overlay welding operations. As long as they are fully incorporated herein by reference. Thereafter, when a more accurate deposition method is desired for the workpiece configuration, the controller 195 switches to the droplet deposition method described above. The controller 195 can control the system described herein to utilize the droplet deposition and cladding deposition processes as needed to achieve the desired configuration.

  The above-described embodiments can perform high-speed droplet deposition. For example, embodiments of the present invention can achieve droplet deposition in the range of 10-200 Hz. Of course, other ranges can also be realized depending on the operating parameters. In some embodiments, the droplet deposition frequency can be higher than 200 Hz, depending on some of the operating parameters. For example, large diameter wires typically use deposition frequencies below 200 Hz, while small diameter wires, for example in the range of 0.010 to 0.020 inches, can achieve faster frequencies. Other factors that affect droplet deposition frequency include laser power, workpiece size and shape, wire size, wire type, travel speed, and others.

  FIG. 13 illustrates another exemplary embodiment of the present invention in which a plurality of welding materials can be deposited simultaneously. In the illustrated embodiment, four welding materials are deposited. However, since any number can be used, embodiments are not limited in this respect. In such embodiments, workpiece construction can be accelerated because multiple weld materials can be deposited in a single pass. Other advantages to such a configuration are also obtained, as will be described further below.

  As shown in exemplary system 1300, contact tip assembly 1305 stores a plurality of contact tips 1303, 1303 ′, 1303 ″, 1303 ″ ″, each of which is (respectively) welded material 140, 140 ′, 140 ″, 140 ″ ′ are fed to the workpiece being formed. In the illustrated embodiment, each of the contact tips is electrically isolated from each other so that each contact tip can receive a separate current waveform used for deposition. For example, as shown in exemplary system 1300, a power source is electrically coupled to each contact chip to provide and control the current waveform for each welding material separately. Note that the system controller 195 is not shown in this figure. However, system 1300 can include a controller 195 as previously described herein, which controls the operation and operation of each of the power supplies. In the illustrated embodiment, the power supply system 1310 includes individual power supply modules P.A. S. # 1 to P.I. S. # 4 (1311, 1312, 1313 and 1314), each of which can output a different current for depositing the weld material. Each of the currents can be similar to the exemplary waveforms described herein having different parameters and the like. Further, each of the power supplies 1311-1314 can be configured and operated similarly to the power supplies described herein with respect to FIGS. In some exemplary embodiments, each of the power supplies 1311-1314 can be a separate power supply module in a single power supply system 1310, eg, in a single enclosure. In other exemplary embodiments, each of the power supplies 1311-1314 can be separate and different power supplies, which can be interconnected to synchronize their operation and otherwise control.

  In operation, the system 1300 can form a workpiece on the substrate S by depositing multiple layers in a single pass. In the embodiment of FIG. 13, each welding material 140-140 ′ ″ forms a separate layer L # 1, L # 2, L # 3, L # 4, with each following welding material being A layer is formed on the preceding layer. This is realized by arranging the chips 1303 to 1303 ″ ″ in a line in the moving direction as shown in the figure. During deposition, the preceding welding material 140 is deposited on the substrate S to form the first layer L # 1, and the following welding material 140 ′ is deposited on the previous layer L # 1 to form the second layer L # 1. Layer L # 2 is formed, and so on. The contact chip assembly 1305 can position the contact chip at different heights with respect to the surface of the substrate S so that the layers can be formed at different heights. As shown in FIG. 13, the contact tips are staggered or stepped to allow for layer stacking. In other exemplary embodiments, the contact tip can be level with respect to its surface, in which case the protrusion distance of the welding material can be adjusted appropriately to achieve the desired stacking.

  In an exemplary embodiment of the invention, the spacing between the weld materials (in the direction of movement) is such that subsequent layers can be appropriately configured over previously deposited layers. In the exemplary embodiment, the spacing is such that the weld material does not deposit in the same molten pool. That is, the following welding material does not contact the preceding molten pool. However, each molten pool is adjacent to each other on the workpiece. That is, in the exemplary embodiment, the weld pools are adjacent to or close to each other, while the molten portions do not contact each other. Of course, the molten pools can be at different height levels (see, eg, FIG. 13), and the temperature of the deposit between the molten pools is very high, but the molten portions do not contact each other.

  Although not shown in FIG. 13, the system 1300 can also use a laser or heat input system as described in the exemplary embodiment above. In particular, the system 1300 can use a laser to form a weld pool and / or help melt the weld material. In some exemplary embodiments, a separate beam can be directed to each separate deposition material deposition step and individually controlled for each respective deposition step. The individual beams can be generated from separate laser generators or can be generated from a single laser generator, but are split into separate beams via optical components, laser splitters, and the like. The deposition of each individual weld material 140-140 "" can be controlled as described above. Alternatively, in other exemplary embodiments, a single laser / heat source can be used, which is irradiated in a raster fashion between the weld materials during the deposition process to provide the desired heat input for each weld material deposition process. provide. For example, a laser beam can be applied to the deposits of each welding material 140-140 ′ ″ in a raster fashion so that the interaction time at each welding material location provides the desired amount of heat input for each deposition operation. To be controlled.

  Within the exemplary embodiments of the present invention, the type, size, and composition of the welding materials 140-140 "" are selected based on the desired properties of the workpiece. In some embodiments, each of the welding materials 140-140 "" is the same and has the same diameter and composition. However, in other exemplary embodiments, the welding material may have different properties. For example, the welding materials 140-140 "" may have different diameters so that the layers L # 1-L # 4 can be formed with different widths by using different diameter welding materials. Further, the welding material can have different compositions to allow the formation of workpieces having different physical / compositional characteristics from place to place. In such embodiments, the composition of the workpiece being manufactured can be changed “in place”. That is, the first material is used to form a specific part of the workpiece (using several contact tips) and then the system can deposit different or additional materials as desired without stopping. Can do.

  For example, exemplary embodiments of the present invention can be used to produce a structure or workpiece using a mixture of stainless steel and mild steel. Furthermore, such a structure can be constructed by adding nickel material. Of course, these are only examples, and embodiments of the present invention allow a desired structure to be constructed from a mixture of materials. In other exemplary embodiments, non-magnetic material / metal bands or layers can be added to the workpiece for a variety of reasons, including workpiece measurements. Different materials can also be used to convert the material to austenitic stainless steel.

  In addition to changing the properties / kinds of the welding material, embodiments of the present invention can supply the welding material 140-140 "" at different wire feed rates. That is, in some embodiments, all wire feed rates of the welding material are the same. However, in other embodiments, it may be desirable to change the wire feed rate. This can be done via the controller 195 and the respective wire delivery system of the weld material (not shown for clarity). By changing the respective wire feed speeds, the physical properties of the workpiece being formed can be affected. For example, it may be desirable to make at least one of the layers L # 1-L # 4 thinner than the remaining layers. In such an embodiment, the wire feed rate of each of the thinner layers of the welding material can be reduced to a thinner layer.

  Further, in the exemplary embodiment, different current waveforms can be provided to the welding materials 140-140 "". In the illustrated system 1300, there are separate power modules 1311-1314 that supply respective deposition currents to the weld material. In some embodiments, each of the currents can be the same, and in other embodiments, the current waveforms can be different to have different frequencies, peak current levels, etc. This is true when ensuring proper deposition using different wire feed rates and / or different welding materials.

  By changing the deposition aspect of any of the welding materials 140-140 "", the system 1300 can greatly increase the formation of the layers L # 1-L # 4. That is, in an exemplary embodiment, any one or combination of the type, composition, diameter, wire feed rate, and deposition current waveform of the welding material can be changed from the other welding materials to achieve the desired layer or deposition process. The characteristics can be realized. Thus, embodiments of the present invention allow a workpiece to be rapidly configured or constructed and yet have great flexibility and accuracy in the configuration or deposition of any layer of the welding material. That is, different layers can have different thicknesses, widths, shapes, etc. based on the use of different composition / weld material properties.

  FIG. 14 shows another view of the system 1300 shown in FIG. As shown and as described above, contact tips 1303 and 1303 'are attached to a contact tip assembly 1305, which directs, holds and moves the contact tips as desired. Further, as described above, the contact tips can be held in a staggered or stepped fashion to form layers up as shown. In such an embodiment, each protrusion X of each welding material 140, 140 'is held at approximately the same distance. However, in other embodiments this may not be the same. In other words, the desired deposition performance can be realized by changing the protrusion distance X for each of the welding materials 140 and 140 ′. Indeed, in some embodiments, the contact tips 1303, 1303 'are coplanar with respect to the surface of the substrate S, respectively. In such a configuration, the protruding distance X of the following welding material (for example, 140 ′) is smaller than each preceding welding material (for example, 140) when the layers L # 1 and L # 2 are configured as shown in the figure. It will be.

  Further, as shown, in some embodiments, contact tips 1303, 1303 ′ are movable within contact tip assembly 1305. In such an embodiment, the desired protrusion of the workpiece being constructed is achieved by moving the contact tips 1303, 1303 ′ out of and into the contact tip assembly 1305 using a roller, actuator, or other actuator mechanism 1320. And / or shapes can be provided. Actuator 1320 can also be controlled by controller 195 (not shown in FIG. 14) to move the contact tip “in place” during the deposition process. For example, during deposition, the relative height of the contact tips and / or the protrusion distance X of the weld material can be adjusted to achieve the desired shape of the workpiece being manufactured. This movement can occur in various ways as described above. For example, the contact chip can be moved as desired using a servo, a motor control roller, a linear actuator, or the like. Such control increases the flexibility of the manufacturing capabilities of the system 1300.

  Although FIGS. 13 and 14 depict the contact tip assembly 1305 such that the welding material is in line in the movement / deposition direction, the contact tip assembly 1305 can also be positioned in a lateral configuration, so that the contact tip Note that is a straight line perpendicular to the direction of movement. That is, the contact tips can be arranged side by side and a wide material can be deposited. In such an embodiment, the welding material is deposited adjacent to each other, rather than upwards as shown in FIGS. Of course, in other exemplary embodiments, the contact tip assembly 1305 can be oriented so that the contact tip is oriented obliquely with respect to the direction of travel. Embodiments of the present invention are not limited in this respect.

  FIG. 15 illustrates another exemplary embodiment in which the contact tip assembly 1305 is also rotatable with respect to the direction of travel of the deposition process. As shown in this top-to-bottom view, at a first location A, the weld material is deposited in a row as shown in FIGS. The contact tip assembly 1305 is rotated to a new position B while continuing to move, so that the layer deposition changes shape as shown. The contact tip assembly 1305 may be any device, such as using a step motor, motor, or any other known system (eg, a system used to control / facilitate movement and rotation in robotic welding). It can also be controlled and rotated by known devices and methods. Controller 195 can be used to control rotation / movement of contact tip assembly 1305 relative to substrate S. By making the assembly 1305 rotatable, the shape of the workpiece can be made as needed. For example, the wall thickness of the workpiece can be increased or decreased as necessary. Further, during rotation of assembly 1305, any one or combination of any of the wire feed rates, current waveforms, protrusions and / or contact tip positions of the weld material can be adjusted. For example, as shown in FIG. 15, before position A, only one of the welding materials is deposited as shown to form layer L # 1. This can be the leading weld material in the assembly. As the assembly 1305 is rotated, the second weld material 140 'begins to be deposited for the second layer L # 2, and the deposit L # 2 is coupled to the first layer L # 1 and above it Added. This can be done to increase only the width of the workpiece being formed without adding an undesirable height. Similarly, as the assembly 1305 is rotated to the desired position B, subsequent weld materials 140 "and 140" "begin to be deposited sequentially as well. Similarly, this motion can be used to form a ledge or overhang on the workpiece, and no additional support for the overhang is required. In such an embodiment, the overhang can be formed relatively easily by rotating the assembly 1305 and adjusting the deposition of any one or all of the welding materials (as described above). For example, a ledge can be made relatively easily by adjusting the feed rate and / or positioning of the protrusion / contact tip depth.

  Thus, the system 1300 significantly increases the manufacturing flexibility of the additive manufacturing processes and systems described herein.

  16, 17A-C, and 18A illustrate an exemplary embodiment of a substrate 1600 that can be used in the methods and systems described herein. The substrate 1600 is conductive and provides a current path for the deposition current / waveform, but also has a non-bonded surface 1610 that facilitates removal of the workpiece from the substrate 1600 for comparison after the manufacturing process is complete.

  In general, in additive manufacturing, the workpiece being constructed is placed on a substrate or surface that is conductive and provides a proper current path for the welding material heating current. However, since the substrate is conductive (ie, metal), the workpiece is bonded to the substrate. That is, during the initial fabrication of the workpiece, the initially formed layer adheres to the substrate through a deposition process. As such, additional processing steps are required to remove the workpiece from the substrate and possibly remove some of the substrate material from the final workpiece. This not only adds additional processing, but also creates a risk of damage to the workpiece. As will be appreciated by those skilled in the art, the bond between the workpiece and the substrate generally occurs when there is a fusion between the workpiece and the substrate, thereby causing material from the workpiece in the contaminated area on the substrate. Is mixed with the substrate material, which is the same as the bonding technique. Embodiments of the present invention address this issue.

FIG. 16 shows an exemplary substrate 1600 made of a conductive material, which allows current to pass therethrough but prevents the work piece 110 from being coupled thereto. For example, in some exemplary embodiments, the substrates can be made from copper or graphite, which are electrically conductive but do not bond to an aluminum or steel workpiece. In other exemplary embodiments, the substrate 1600 can be made as a matrix of many different materials. For example, the substrate 1600 can be made from a matrix material of a non-conductive ceramic or clay material, which has a conductive (eg, metal) material dispersed within the ceramic or clay matrix to create a conductive path. As shown in FIG. 16, the non-conductive matrix 1603 has conductive particles 1605 dispersed throughout it, creating a current path from the surface 1610 to the ground point 1625, to which leads from the power source are connected. it can. In some exemplary embodiments, the substrate 1600 may be primarily a ceramic having copper particles 1605 dispersed therein, from the workpiece surface of the substrate, to the other of the substrate to which the ground or current cable is secured. A sufficient amount of copper to provide a copper concentration capable of transmitting current to The conductive material 1605 can be copper and can be either powder, granular, thread-like, or ribbon-like. However, the conductive material should be distributed so that a conductive path is formed from the substrate 1600 to the ground point 125. The ground point 125 can be located anywhere on the substrate 1600. In some exemplary embodiments, the conductive material need not be evenly distributed throughout the substrate structure 1600, but the workpiece surface 1610 may be positioned on or initiated on the workpiece surface 1610. Note that it should be well distributed to provide a current path from the location. The matrix material 1603 can be any material or combination of materials that does not bond to the workpiece. The material can be non-conductive and have a high melting point so that the surface of the matrix 1603 does not melt during the formation of the workpiece on the substrate. As described above, the matrix material may be any one of clay, ceramic, or a combination thereof. Other materials can include cast iron with a high carbon content or any other alloy that becomes brittle when an additional step is performed on the substrate. As mentioned above, the contamination in the addition process is at a relatively low level (if any), so that the propagation of the alloy from the substrate to the construction is minimal. However, the propagation can be such that the first layer of the structure becomes brittle while at the same time maintaining electrical conductivity. When the structure is complete, the user can easily bend and break the fragile interface and separate the structure from the substrate. As described above, a ceramic material can be used for the substrate. Such ceramics should have a high melting point, such as Al ₂ O ₃ or other similar ceramics. In other examples, an aluminum material or alloy can be used as a substrate for a mild steel construction.

  In another exemplary embodiment, the substrate can be made from a concentration of metal powder such that the substrate provides the desired electrical conductivity and physical support for the build workpiece. In such embodiments, the powder can be easily removed from the construction part after completion. In yet another exemplary embodiment, the substrate is a conductive layer (eg, copper) that is placed on a foundation of a non-conductive material, such as a ceramic, that may or may not have a conductive material in the base material. , Carbon, iron, etc.). By using a thin layer on the base material, bite into the substrate can be minimized, and therefore bonding to the substrate does not occur reliably.

  As shown in FIG. 16, in some exemplary embodiments, the substrate 1600 can have a contact region 1620 with conductive material present therein and no conductive material present outside thereof. , To a lesser extent, the substrate 1600 is less conductive or non-conductive outside the contact region 1620. In such an embodiment, the workpiece 110 is initiated on or placed on the surface 1610 to make contact with the contact area 1620 to ensure sufficient electrical contact, which is the contact area. This is because there is little or no conductivity outside the 1620. In such an embodiment, the area of contact region 1620 is less than the area of surface 1610. Further, the contact area 1620 can be formed in any desired shape. Thus, in the exemplary embodiment, to begin the additive manufacturing process, the process begins with the contact area 1620 of the surface 1610 to ensure that a current path for the workpiece is obtained. In constructing the workpiece 110, a portion of the workpiece can also be formed outside the contact area 1620 on the surface 1610 as long as the workpiece is an integral part and thus has a continuous current path. Therefore, a current path for the manufacturing process is always provided and the workpiece 110 can be formed on a conductive surface 1610 that does not couple to the workpiece 110, thereby facilitating removal and processing of the workpiece.

  FIG. 17A illustrates another exemplary embodiment, in which substrate 1600 has a grid 1630 of conductive material that forms a grid structure on surface 1610 of substrate 100. A grid 1630 made of a conductive material such as copper is embedded in the material of the substrate 1600, which can be a ceramic, clay or other non-conductive material. The grid 1630 has a grid structure formed on the surface 1610 so that the work piece contacts at least a portion of the grid 1630 to provide the necessary conductive path regardless of the size or orientation of the work piece 110 to be formed. Can be configured as provided. The grid 1630 will have a mesh size that provides the desired spacing for the size of the workpiece to be made on the substrate 1600. In some embodiments, the grating 1630 can have a depth that penetrates the substrate 1600, and in other embodiments, the depth of the grating 1630 does not span the entire substrate 1600. Further, the grid structure 1630 is formed such that the entire structure is conductive and an electrical path is provided to the ground point 1625 regardless of where the workpiece contacts the grid structure 1630. Further, in the exemplary embodiment, the lattice structure 1630 can exist only in contact areas on the substrate 1600, similar to that described with respect to FIG. That is, the grid structure exposed at surface 1610 is only in the discrete portions (ie, contact areas) of surface 1610 and the grid is coupled to ground point 1625. In such an embodiment, as long as a portion of the workpiece is in the contact area and contacts a portion of the grid 1630, a current path exists and the workpiece can be manufactured. However, again, because most of the surface 1610 is non-conductive and non-bonding, removal and processing of the workpiece is easier compared to known substrates.

  FIG. 17B shows another exemplary embodiment of a substrate 1600 that can be used in the apparatus described herein. In this embodiment, the substrate 1600 includes a plurality of individual ground points 1651/1652/1653, etc. distributed over the entire area of the substrate 1600. The points can be distributed in a pattern, such as a grid pattern, so that their respective positions are visible to the controller of any system that uses the substrate. The ground point can be made of a conductive material and can be a wire, pin, or the like, and can penetrate through the substrate 1600 and expose each of them on the other surface of the substrate 1600. In the embodiment shown in FIG. 17B, the ground point penetrates the substrate 1600 and its opposite end is exposed on the bottom surface of the substrate 1600. In other embodiments, the opposite end can be extended from the side as desired. The ground points 1651, 1652, 1653, etc. are electrically connected to the switching circuit 1660, which is also electrically connected to the system and a controller that controls the operation of the earth switch in the circuit 1660 as described below. The Since the location of the ground point is known, the additional process can begin at one of the ground points (eg, point 1651) that serves as the initial ground path for the additional process. When the process begins, the weld pool can move along the surface 1610 until it reaches the next ground point 1652. The switching circuit 1660 allows the controller to switch the ground point of the construction process to the ground point closest to the continuous additional process. That is, as the process contact tip is moved, the ground point can be switched to provide the ground path closest to the job. Furthermore, in other exemplary embodiments, the switching circuit 1660 can open multiple ground paths through multiple ground points to increase the amount of current available for the process. Further, in the exemplary embodiment, switching circuit 1660 can be used to drive the ground current path to a different position to control the deposition process. For example, as the build process approaches the edge of the substrate 1600, the switch 1660 can switch to a ground point that is closer to the center of the substrate 1600 to help control the deposition process and the weld pool. It can also be used to help control the direction of the arc if any arc is formed during the deposition process.

  FIG. 17C illustrates another exemplary embodiment of the present invention in which the substrate 1600 further includes a conductor 1670 that electrically connects all of the ground points 1651, 1652, 1653, etc. Connected to the power supply, the ground path for the deposition current is completed. In such an embodiment, it is not necessary to use the switching circuit 1660 described above. In the illustrated embodiment, conductor 1670 is a conductive plate or layer attached to the surface of substrate 1600 to which all ground points are coupled. Of course, the conductor 1670 may not be on the bottom surface and may be on another surface of the substrate 1600. In use, when the construction structure contacts multiple ground points 1651, etc., an additional ground path is provided to the conductor 1670, which also allows more current to be used during the process. In any of the above embodiments, the controller / power supply used in the deposition process can control the deposition current level so as not to exceed an acceptable current level for any ground point. That is, if only one ground point 1651 is used at the start of the build process, the current is controlled such that the current level does not exceed an acceptable level for one ground point 1651. Doing so causes damage to the grounding point. However, as construction proceeds to other ground points, the controller can increase the current level because it contacts other ground points, ie, the number of ground paths to conductor 1670 increases. Thus, in such an embodiment, the controller knows the location of each ground point, so the controller can increase the current when multiple ground points are utilized. In such embodiments, the deposition current can be increased in steps for each contact of each ground point, or it can be increased once when it contacts the appropriate number of ground points. For example, for a 200 amp deposition current, the controller can determine (using stored information) that such a current level requires a minimum of four ground points. The controller / power supply can utilize the first, lower current level (eg, 50 amps) until at least four ground points touch, at which point the deposition current is increased to an optimal level. In other embodiments, the current can be increased in steps each time a new ground point touches, until the minimum required ground point touches. For example, the current can be increased by 50 amperes for each successive ground point until the desired deposition current level is reached. The current increase step can be pre-set / pre-programmed in the system controller.

  In an exemplary embodiment of the invention, the ground point is a wire or pin having an average diameter that is greater than that of the wire diameter used. In an exemplary embodiment, the ground point is a pin having an average diameter that is at least 20% greater than the largest wire diameter used. In some exemplary embodiments, the diameter is 20-80% greater than the diameter of the largest diameter wire. Further, as shown in FIG. 17C, the pins can have a larger head area as shown to further increase contact with the workpiece. That is, the pin can have a larger head area (eg, a nail or the like) at the contact surface of the substrate, see for example FIG. 17C. As long as the pins 1651 and others have the shape shown in FIG. 17C, the larger head area is not considered in determining the average pin diameter described above.

  In another exemplary embodiment, ground point 1651 etc. (eg, pins, wires, rods, etc.) are removable and replaceable within substrate 1600. For example, as shown in FIG. 17C, the pins simply fit into holes in the substrate and function as the ground point described above. Through mixing, the pins are fixed to the work piece at the time of construction, and after completion, the work piece is removed together with the fixed pins. The pins / rods, etc. can then be removed via a machining process and new pins can be replaced in the substrate 1600 for the next process. The removable pins 1651 and the like should be long enough to contact the workpiece being built on the substrate and the contact plate 1670 to form a proper ground current path.

  FIG. 18A illustrates another exemplary embodiment of the present invention in which the substrate 1600 includes at least one cooling channel 1640 where the coolant is present during manufacture of the workpiece, or at least during initial manufacture of the workpiece. You can pass through it. The refrigerant can be a gas or a liquid and is used to keep the substrate at a temperature so that none of the surface 1610 melts or otherwise adheres to the workpiece. By cooling the substrate 1600 through the use of a cooling manifold / channel 1640, the substrate 1610 can be held at a low temperature, keeping all of the conductive material (eg, lattice structure, conductive particles, etc.) on the surface 1610 at a low temperature. Thus, any layer of the workpiece formed on the surface 1610 may not melt or otherwise bond to conductive components on the substrate 1610. Other embodiments may use other cooling methods / steps, which do not depart from the scope or spirit of the invention. For example, a passive heat pipe can be used.

  Thus, in an exemplary embodiment, a substrate is provided that provides the necessary electrical conductivity, but provides a non-bonded surface so that removal and processing of the workpiece after fabrication is easier.

  FIG. 18B shows yet another structure that can be used in the exemplary additive manufacturing process described herein. The additive manufacturing process described herein can be used to produce complex and delicate workpieces. Easy manufacture of such components is aided by starting the manufacturing process from a non-horizontal conventional substrate or workbench surface. For example, it may be advantageous to manufacture the workpiece in a suspended manner. That is, an initial layer / deposit of the workpiece may be suspended, which may be easier to manufacture with a workpiece that extends from the bottom of the substrate, as opposed to a conventional flat surface substrate from bottom to top. The embodiment shown in FIG. 18B shows an exemplary truss structure 1800 that can be used in such a situation. The truss structure 1800 can have a plurality of support components 1810 and 1820 that are electrically connected to each other to conduct current. The truss structure 1800 can begin at any point on the structure 1800 where the work piece is desired for the work piece. For example, if it is easier to manufacture the workpiece upside down or in a top-down process, the part can be removed from a point on one of members 1810 and 1820 by the process described herein. You can start and build down. Of course, the truss structure and torch / contact tip used should be designed so that the tip can be properly positioned within the truss structure 1800. This part can then be built down from the structure 1810/1820 as needed toward the surface of the substrate 1600. As shown, the truss structure 1800 can have its own ground contact 1825 or can simply be entirely conductive. Further, in some exemplary embodiments, the truss structure may have a contact projection 1830 on which the starting portion of the part or workpiece is secured and the building operation begins. These protrusions 1830 function as contact nodes, from which the starting part of the workpiece is started. These protrusions can facilitate the start of the manufacturing process, can facilitate the separation of the final part from the truss structure, and do not damage the manufactured part. The protrusion 1830 can be made integral with the part 1810/1820 of the structure 1800. In other embodiments, the protrusion 1830 can be made of a material different from the structure and / or can be easily separated therefrom. For example, the protrusion 1830 can be a pin or other fixture-type component having a head or protrusion portion on which a part for performing a manufacturing process can be fixed and started. After completion, the pin can be removed from the truss structure, thereby facilitating removal of the manufactured part. The truss structure 1800 can take any shape or configuration desirable for a manufacturing process.

  In the exemplary embodiment, truss structure 1800 can be a metal structure, whereby current can be transferred to substrate 1600, which can be any of the previous embodiments. In other exemplary embodiments, the truss structure is non-bonded but can be made of a conductive material, as generally described above with respect to FIGS. In any case, structure 1800 should be configured such that it provides a current path to either substrate 1600 or ground point 1825 so that the heating current can flow properly.

  19A, 19B, and 19C illustrate an exemplary embodiment of an additive manufacturing welding material 1900 that can be used in the embodiments of the invention described herein. It is generally understood that large diameter solid weld materials require more current / energy to melt the weld material. However, smaller diameter welding materials may require less current / energy for melting, thereby collectively having multiple cross-sectional areas having the same cross-sectional area as a single larger diameter solid wire. The amount of current / energy required to melt the small diameter welding material may also be small. Therefore, the welding material used in some embodiments of the present invention is a braided welding material made from a braid of a plurality of wires 1903. In some embodiments, the wires 1903 are the same and have the same diameter and composition. However, in other exemplary embodiments, the wires 1903 may be different from each other. For example, in some embodiments, two different wire types can be used to make braided weld material 1900. In such embodiments, the wires may vary based on diameter and / or composition. For example, the central wire can have a first diameter and composition, and the peripheral wires 1903 both have a second diameter and composition that is different from the first diameter and composition. This allows the use of a weld material 1900 having properties customized for a particular manufacturing process. It should be noted that the method and system for depositing a solid or cored weld material described herein can be used to deposit a braided weld material as shown in FIG. 19A.

  Further, in the embodiment shown in FIG. 19A, the central wire 1903 'is a non-braided wire and the outer periphery of the wire 1903 is braided around the central wire 1903'. The braid can be made in a generally spiral pattern along the length of the weld material 1900.

  In some exemplary embodiments, a braid of welding material 1900 can be used to increase the relative wire delivery speed of a type of welding material. For example, as shown in FIG. 19A, the central welding material 1903 can be of the first type / material, and the surrounding wire 1903 can be of a different type / material. Because the length of the surrounding (outer) wire is longer than the center wire, for a length of welding material 1900, the effective deposition rate of each of the respective wire types is different. The effective relative deposition rate of different wire types can also be affected by the relative number of wire types in a bundle. Therefore, embodiments of the present invention can increase the flexibility of the nature of the deposition.

  19B and 19C illustrate other exemplary embodiments of welding materials that can be used in embodiments of the present invention. However, unlike the welding material 1900 of FIG. 19A, the welding material 1900 of FIGS. 19B and 19C has a void 1910 in the core of the welding material, and the core 1910 is surrounded by a plurality of braided wires 1903. This hollow weld material configuration allows the weld material 1900 to be compressed and “shaped” during deposition, allowing the deposition process to be customized. This will be described in more detail later.

  The braiding of the wire 1903 forming the outside of the welding material 1900 is performed in a generally spiral pattern, similar to known wire braiding methods, but the void 1910 is retained in the core of the welding material 1900. Similar to FIG. 19A, the wire 1903 can have the same diameter and composition in some embodiments, and in other embodiments, the wire 1903 can have different properties. An example of this is shown in FIG. 19C, in which the braid is a first type of wire 1903 having a first diameter and composition, and a second type of wire 1905 having a second diameter and composition. including. Of course, in some embodiments, the wire 1903/1905 can have the same composition even though the diameters are different. As shown in FIG. 19C, different wires 1903/1905 alternately cover the periphery of the cross-section of the weld material 1900. In another exemplary embodiment, the wires 1903/1905 can have different melting points so that the deposition shape and layer formation can be customized as needed.

  The void 1910 should be dimensioned such that the weld material 1900 'remains relatively stable during the deposition process. If the voids are too large, the weld material becomes unstable and does not maintain its integrity during the deposition process. In the exemplary embodiment, the diameter of void 1910 is in the range of 5-40% of the effective diameter of weld material 1900 '. “Diameter of gap 1910” is the diameter of the largest circular cross-section that fits into gap 1910, as shown by the dashed circle in FIG. 19C. The “effective diameter” of the welding material 1900 ′ is the diameter of a circle having the same cross-sectional area as the total cross-sectional area of all the wires 1903/1905 constituting the welding material 1900 ′.

  As described above, the welding material 1900 having the central void 1910 can be shaped such that the deposition characteristics of the welding material can be changed during the deposition process. This is shown generally in FIGS. 20A and 20B, in which the weld material 1900 is compressed in a direction that can achieve the desired width of the volume with respect to the direction of movement of the weld material. As described herein, the process and system of the present invention can be used to create complex shapes through additive manufacturing. Therefore, workpieces and shapes with varying thicknesses and the like can be made. According to the welding material 1900 shown in FIGS. 19B and 19C, these complex shapes and different thicknesses can easily be created by the voids. In FIG. 20A, the welding material is compressed in a direction perpendicular to the moving direction, and the welding material 1900 becomes narrower with respect to the moving direction. By doing this, the resulting deposit is narrower than the original diameter of the weld material. Similarly, FIG. 20B shows that the same weld material 1900 is compressed in a direction along the direction of movement, which causes the weld material 1900 to be wider with respect to the direction of movement. Therefore, such compression allows more extensive deposition as needed. As described above, the void 1910 should be sized / diametered such that deformation of the weld material 1900 can change its relative width compared to its uncompressed state.

  In some exemplary embodiments, the void 1910 can be filled with a desired property of flux or powder required for deposition. This can help deliver the desired material to the construct that is difficult to wire or move through melting of the wire. For example, an abrasion resistant powder can be added as a flux.

  FIG. 20C illustrates another exemplary embodiment of a contact tip assembly 2000 and welding material supply system and method that can be used in embodiments of the present invention. In this embodiment, at least two welding materials 2010 and 2020 are directed to contact tip assembly 2000 and contact tip 2040, which has a hole 2030 through which both welding materials can pass. Unlike the embodiments described above, the welding materials 2010 and 2020 are not braided. They can be supplied from the same welding material source (spool, reel, etc.) or from different sources. Further, they can be the same weld material having the same dimensions and composition, or they can be different as desired for certain manufacturing operations. In another exemplary embodiment, the welding materials 2010 and 2020 can be delivered at different rates, and in some embodiments, the delivery rate can be changed “in place” during the deposition process. Such an embodiment allows the alloy to be customized to the construct during the deposition process. For example, in the first part of the process, the welding materials 2010 and 2020 are delivered at the same rate, but at another stage of the build process, the desired deposition rate can be increased by increasing or decreasing the speed of the welding material 2010 as needed. Give nature.

  In addition, although two welding materials are shown, other embodiments can use three or more as needed. In the illustrated embodiment, the welding materials 2010 and 2020 are fed into holes 2030 (which can be oval or any other shape that can accommodate the welding material), followed by a known welding material feed. Directed to the workpiece using the system. During deposition, the contact tip 2040 is oriented such that the welding material provides the desired deposit profile. In addition, the contact tip 2040 is rotatable (similar to the embodiment described above) and the deposition material can be oriented as designed to change the shape or contour of the deposition process as desired. For example, as shown, the left orientation indicates a single row orientation, which provides a narrow deposit on the workpiece, but the height is higher because the weld material is in a row in the direction of travel. Then, the contact tip 2040 can be rotated to the position shown on the right side as necessary. Rotation can be performed by the controller 195, motor, etc., and can be used during the change of the deposition direction, without changing the torch orientation. The right position can be used when it is desirable to increase the width of the deposit in the direction of travel. Note also that in some embodiments, both welding materials 2010 and 2020 may not be delivered simultaneously. In such an embodiment, the welding materials 2010 and 2020 are fed by separate wire feeders (not shown) and the controller 195 feeds which of the welding materials is being fed or they are fed simultaneously. Can be controlled. In such an embodiment, undelivered weld material need not be extracted from hole 2030 and can therefore be used to hold the position of the weld material being delivered. In such an embodiment, the delivery of the welding material can be controlled by the controller 195, which delivers one or both of the welding materials as needed at a certain moment in the process.

  Further, in the embodiment shown in FIG. 20C, each of the welding materials 2010 and 2020 shares the same current because they are directed through one hole 2030. In such an embodiment, the current can be supplied from a single power source and the current is shared by each welding material. However, FIG. 20D shows a different exemplary embodiment. In the embodiment shown in FIG. 20D, contact tip assembly 2000 includes two contact tip portions 2015 and 2025 that are electrically isolated. Tip portions 2015 and 2025 supply welding materials 2010 and 2020, respectively. However, assembly 2000 includes a switching device or mechanism 2050 that can electrically connect tip portions 2015 and 2025 to each other so that they share current or electrically isolate the tip portions from each other. it can. In an exemplary embodiment, each of chip portions 2015 and 2025 are coupled to separate power supplies (PS # 1 and PS # 2). When the switch 2050 is in the open position, each power source can each supply a different heating current to its respective welding material. In such embodiments, the welding material can be deposited at different rates or can be different in size and composition. This can be controlled and used as an embodiment similar to that described above using a plurality of welding materials. However, in this embodiment, if desired, the controller 195 can close the switch, at which time the contact tip portions 2015 and 2025 are electrically coupled and the power supply P.P. S. # 1 or P.I. S. A single current signal from one of # 2 can be shared. In such embodiments, it may be sufficient to operate a single power supply for certain tasks to reduce power usage and / or eliminate the need for signal synchronization. In such an embodiment, the switch 2050 can be closed, which in turn allows each of the tip portions 2015 and 2025 to be interconnected, with the welding materials 2010 and 2020 sharing the same signal from a single source. When switch 2050 is opened, the chip portions are electrically isolated from each other (through dielectric material or other suitable means) and if they are to deposit both deposited materials, they receive separate signals from separate power sources. Alternatively, a single weld material may be deposited at some point during the deposition operation. Therefore, while only one power supply is operating, switch 2050 opens for safety and insulates the other weld material. The switching mechanism 2050 can be any switch structure that can insulate and connect the chip portions 2015 and 2025 and can be integrated into the chip assembly 2000 or separated from the assembly 2000 as desired.

  Referring now to FIGS. 21A and 21B, there is shown a schematic diagram of a representative contact tip assembly 1950 that uses the welding material 1900 of FIG. 19B. FIGS. 21A and 21B show views of the exit portion of contact tip assembly 1950, FIG. 21A shows the weld material in an uncompressed state, and FIG. 21B shows the weld material 1900 in a compressed state. . It should be noted that the following description of the contact tip assembly 1950 is for illustrative purposes, and those skilled in the art will be able to shape the welding material 1900 as desired to achieve the desired deposition during the additive manufacturing process. It will be appreciated that other configurations and designs can be used.

  As shown, the contact tip assembly 1950 has a welding material opening 1951 through which the welding material passes. Although the opening 1951 is shown as a square, embodiments of the present invention are not limited in this regard, as long as the weld material 1900 can pass through either in its compressed state or in its uncompressed state. Can also be used. In the illustrated embodiment, the assembly 1950 has two pairs of contact plungers 1953 and 1955. The plungers are movable with respect to the opening 1951 as shown, so that they extend into the opening and therefore a compressive force can be applied to the welding material 1900. Contact plungers 1953 and 1955 are oriented such that a pair of plungers 1953 can move in a direction perpendicular to the direction of movement of the other set of plungers 1955. Therefore, as shown in FIG. 21B, the plunger 1953/1955 can compress the weld material 1900 in the desired direction to achieve the desired shape. Each set of plungers can be moved through a known actuator device 1956, such as a linear actuator, and can be controlled by a controller 195 (not shown in these figures). Further, each of the plungers 1953/1955 is configured to supply a heating current waveform to the welding material 1900, whereby a heating current is supplied to the welding material 1900 via the plunger. Note that although one actuator 1956 and bias 1957 are shown in the figure, the exemplary embodiment will have similar components for each of the plungers.

  As shown in FIG. 21A, in the uncompressed state, each of the plungers 1953/1955 contacts the welding material 1900 to provide a heating current. The plunger 1953/1955 is held in a position that ensures that the welding material 1900 is held in its natural state with respect to the opening 1951. It is then determined that during deposition, the width of the weld material should be changed to achieve the desired deposition configuration (eg, by the controller), ie, the weld material should be wider or narrower as needed. Is done. Based on this information, the controller 195 activates the plunger 1955 (via the actuator 1956) and moves inward to compress the weld material 1900 as shown in FIG. 21B. In addition to this, the plunger 1953 is pulled back so that the shape of the welding material 1900 can be changed so as to cope with the change in the shape of the welding material 1900. However, in the exemplary embodiment, the retracted plunger 1953 is still in contact with the weld material 1900, holding the weld material 1900 in place and providing a heating current.

  During the deposition process, the shape of the weld material 1900 can be changed “in place” by moving the plunger to achieve the desired shape. For example, the controller 195 controls the plunger 1953/1955 during deposition to retract and extend as necessary to change the shape of the weld material 1900 from wide to narrow and vice versa. You can change without stopping.

  As described above, movement / actuation of the plungers 1953/1955 can be achieved by any known actuator, and the moving device causes the desired movement. In some exemplary embodiments, each plunger (not shown here) of each pair of plungers is mechanically coupled to each other so that their relative motion is kept consistent with each other. can do. In such an embodiment, rather than having a separate actuator for each plunger, a single actuator can be used for each respective pair, and each of the plungers is moved appropriately by mechanical coupling.

  Further, as described above, the controller 195 can control the operation of the plunger based on the desired shape to be constructed. In another exemplary embodiment, assembly 1950 can be rotated as desired during the deposition operation to achieve the desired shape. That is, the assembly 1950 can be coupled to a rotary motor and / or a robotic arm (or other similar motion device), and the controller 195 (or other system controller) can rotate the assembly as needed and either of the plungers Can be activated to achieve the desired welding material, and hence the deposit, shape.

  FIG. 22 illustrates another exemplary embodiment of a welding material 2000 that can be used in an exemplary embodiment of the present invention. The welding material 2000 includes a braided structure of a wire 2003 having a space 2010 similar to that described above, but also includes a jacket 2015. The jacket 2015 can be configured and formed in the same manner as known jacket structures used for welding materials for welding or brazing. As shown, in this embodiment, the jacket 2015 completely surrounds the wire 2003 and has a seam 2017, which is a butt seam. The jacket 2015 can be made of any material that is desired to be deposited on the workpiece. In some embodiments, the jacket 2015 can be the same material as the wire 2003, and in other embodiments, the jacket can be made of a different material / have a different composition. The jacket 2015 can also help maintain the shape of the weld material 2000 after being deformed by the plunger in the contact tip assembly of FIGS. 21A and 21B. Specifically, by compressing the wire passing through the hole 1951, the jacket 2015 is plastically deformed, and therefore the welding material 2000 is more easily maintained in a desired shape. Thereby, the protrusion part of the welding material 2000 can be enlarged during a deposition process.

  FIG. 23 illustrates another exemplary welding material 2100 that can be used in embodiments of the present invention. The welding material 2100 includes a jacket 2110 and a core 2120, and the melting point of the jacket 2110 is lower than that of the core 2120. By having such different melting points, embodiments of the welding material 2100 can better control the manufacture of the components. In embodiments where the weld material is generally melted generally at the same temperature, the dynamics of the weld pool formed plays an important role in the deposition and build process. In certain instances, control of the weld pool can be difficult, especially during high precision manufacturing processes or when the thickness of the workpiece being constructed is very thin. In such applications, the molten pool dynamics can be difficult to control and explain. However, when the welding material 2100 is used, the outer cover 2110 is melted before the core 2120. The melted jacket material then provides a molten matrix to adhere the core material to the workpiece. In such applications, the importance of the weld pool is reduced, and in some cases the weld pool can be eliminated. In addition, in an alternative embodiment, the size and / or depth of the weld pool can be reduced because the weld pool and molten jacket material cooperate to adhere the core material to the workpiece. is there. Therefore, when the welding material 2100 is used, the importance of the dynamics of the weld pool can be further reduced.

  In the exemplary embodiment, core 2120 can be a solid core, and in other embodiments, core 2120 can be a powder or particles of the desired material. In such an embodiment, the welding material 2100 can be shaped to achieve the desired deposition (as described above). That is, since the core 2120 can be powdered or granular, the outer side of the welding material 2100 can be molded and compressed to achieve a desired welding material profile. In other embodiments, the welding material can be configured at least as shown in FIG. 22, in which a jacket surrounds a plurality of individual wires and at least some (or all) of the wires 2003. The melting point of is higher than that of the jacket 2015. In fact, in some of such embodiments, the wires 2003 can have different melting points with respect to each other. For example, the first number of wires 2003 can have a first melting point (which is higher than the melting point of the jacket), and is the second number of wires 2003 higher than the melting point of the first number of wires 2003? Can have a low melting point. Such an embodiment can improve the flexibility in melting and construction profile of the weld material. Further, in some embodiments, the heat source (eg, laser) and / or current is controlled such that at least some of the core 2120 melts during the deposition process. However, in other embodiments, the core 2120 material does not melt during the deposition process. That is, the jacket 2110 is melted and the liquid jacket material is used to fix the unmelted core material to the workpiece. In such an embodiment, the workpiece is formed in a layered manner in which the melted jacket material and core material alternate. Although FIG. 23 depicts the welding material 2100 as having a circular cross-section, it is noted that embodiments of the present invention are not limited in this respect. The weld material 2100 can also have any desired shape that favors the configuration of the workpiece, as desired. For example, the welding material 2100 can have a square, rectangular, polygonal, or oval cross section. Of course, other shapes can be used.

  In the exemplary embodiment, the material of the jacket 2110 and the core 2120 is selected such that the jacket 2110 melts at a temperature 5 to 45% lower than that of the core material. In another exemplary embodiment, the melting point of the jacket 2110 is 10-35% lower than that of the core material. Of course, the exact composition of the jacket and core materials will be selected based on the desired composition and configuration of the workpiece being built.

  FIG. 24A shows another exemplary embodiment in which the weld material 2200 has a non-circular cross-section and the jacket material 2210 does not extend along the entire circumference of the weld material 2200. That is, the welding material 2200 has an asymmetric cross section. For example, in the illustrated embodiment, the jacket material 2210 is only on one side of the core material 2220 of the welding material. FIG. 24B illustrates another such exemplary embodiment, in which the overall shape of the weld material is hexagonal and the jacket material 2210 ′ is only five sides of the hexagonal cross section of the core 2220 ′. Coating. Of course, other shapes and coverages can be used based on the desired performance and deposition characteristics of the weld material. FIG. 24C shows another exemplary embodiment, which shows a weld material 2200 ″ that has a symmetric cross-section, but the distribution of jacket material 2210 ′ and core material 2220 ″ is not symmetric. This configuration allows the weld material to be used with contact tips and equipment designed for general symmetric weld materials, but the weld material itself is asymmetric. In such an embodiment, the jacket material 2210 melts to provide an adhesive means for the core portion 2220 of the weld material, but does not melt from the entire circumference of the weld material. In such embodiments, the welding material can be oriented in a desired manner prior to bonding during the deposition process. The jacket material functions as an adhesive material, which adheres or bonds the core material to the workpiece. Further, in such an embodiment, the current input / heat input is controlled such that the desired melting of the jacket material can be achieved without completely melting the core material.

  FIG. 24D is another exemplary embodiment of a welding material 2200 '' that can be used in embodiments of the present invention. The welding material 2200 '' is similar to that described above, with the exception that the envelope layer 2210 '' has a layered structure. In such an embodiment, the envelope layer 2210 ″ may be a solid material or a flux. In practice, in any of the embodiments described above, the jacket layer can be a flux. In these embodiments, in some applications, it may be desirable to place material in the flux jacket that should not melt (or minimize melting) during the deposition process. To accomplish this, in some embodiments, a layered envelope / flux 2210 '' 'is used, in which the flux composition relative to the surface S of the core 2220' '' is at the outer edge of the flux. Different from the nature of the flux. This is shown in FIG. 24D as layers A and B, where layer A has a first composition and layer B has a second composition. For the formation of these layers, known deposition methods can be used, the description of which is not necessary here. This type of configuration allows the material of layer B to be removed from the direct heat of the core 2220 ′ ″ that would otherwise melt the components in layer B. For example, it may be desirable to deposit tungsten carbide in the molten pool, which may be susceptible to melting when they are in direct contact with the core 2220 '' '. In this embodiment, layer A functions as a thermal barrier, allowing the material of layer B to be deposited with little or no melting. Of course, it should be understood that the boundary between the two layers A and B need not be a clear and precise line, but can be a transition from one component to another. Further, the shape and relative cross-sectional area of layer B relative to layer A can be determined based on the configuration desired for the application. FIG. 24D is shown as an exemplary embodiment, and other shapes and configurations may be used, without departing from the spirit or scope of the present invention.

  A user interface coupled to a computer illustrates one possible hardware configuration configured to support the systems and methods described herein, including the controller 195 or the present specification. Similar systems used to control and / or operate the systems described therein are included. In order to further illustrate various aspects of the present invention, the following description provides a brief general description of a suitable computing environment in which various aspects of the invention may be implemented. As will be appreciated by those skilled in the art, the present invention may be implemented in combination with other program modules and / or as a combination of hardware and software. Generally, program modules include routines, programs, components, data structures, etc. that perform particular tasks or implement particular abstract data types.

  Furthermore, as will be appreciated by those skilled in the art, the method of the present invention is applicable to single processor or multiprocessor computer systems, minicomputers, mainframe computers, and personal computers, handheld computing devices, microprocessor-based or programmable consumer electronics. It may be implemented in other computer system configurations, including devices, and others, each of which may be operatively coupled to one or more associated devices. The described aspects of the invention may also be practiced in distributed computing environments where certain tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be in both local and remote memory storage devices.

  The controller 195 can utilize an exemplary environment for implementing various aspects of the invention, including a computer, in which the computer includes a processing unit, a system memory, and a system bus. The system bus couples system components, including but not limited to system memory, to the processing unit. The processing unit may be any of various commercially available processors. Dual microprocessors and other multiprocessor architectures are also available as processing units.

  The system bus can be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of commercially available bus architectures. The system memory can include a read only memory (ROM) and a random access memory (RAM). A basic input / output system (BIOS) including a basic routine for supporting information transmission between elements in the computer at the time of startup or the like is stored in the ROM.

  The controller 195 is for reading from or writing to a hard disk drive, for example, a magnetic disk for reading from or writing to a removable disk, for example, a CD-ROM disk, or from other optical media. An optical disk drive can be further included. The controller 195 can include at least some form of computer readable media. Computer readable media can be any available media that can be accessed by a computer. For example, computer readable media may include, but is not limited to, computer storage media and communication media. Computer storage media include volatile and nonvolatile, removable and non-removable media implemented in any method or technique for storing information such as computer readable instructions, data structures, program modules or other data. . Computer storage media stores RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, Digital Versatile Disk (DVD), or other magnetic storage device, or any desired information and is coupled to controller 195 Including, but not limited to, any other medium that can be accessed by a customized user interface.

  Communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes some information delivery media. The term “modulated data signal” means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. For example, but not limited to, communication media includes wired media such as a wired network or straight-line connection, and wireless media such as acoustic, RF, infrared and other wireless media. Combinations of any of the above should also be included within the scope of computer-readable media.

  A number of program modules may be stored in the drive and RAM, including the operating system, one or more application programs, other program modules, and program data. The operating system in the computer or user interface 300 can be any of various commercially available operating systems.

  In addition, the user may input commands and information into the computer through a keyboard or a pointing device such as a mouse. Other input devices may include a microphone, IR remote controller, trackball, pen input device, joystick, game pad, digitizing tablet, satellite TV receiving antenna, scanner, or others. These and other input devices are often connected to the processing unit through a serial port interface coupled to the system bus, eg, parallel port, game port, Universal Serial Bus (“USB”), IR interface, and / or various It may be connected by other interfaces such as wireless technology. A monitor or other type of display device may also be connected to the system bus via an interface, such as a video adapter. Video output may also be implemented through Remote Desktop Protocol, VNC, X-Window System, and other remote display network protocols. In addition to video output, computers typically include other peripheral output devices such as speakers, printers, and the like.

  The display can be used with a user interface coupled to the controller 195 to display data received electronically from the processing unit. For example, the display can be an LCD, plasma, CRT, or other monitor that electronically displays data. Alternatively or additionally, the display can display received data in a hardcopy format, such as a printer, facsimile, plotter, etc. The display can display data in any color and can receive data from the user interface by any wireless or hardwire protocol and / or standard.

  The computer can operate in a network environment using logical or physical connections with one or more remote computers, such as a remote computer. The remote computer can be a workstation, server computer, router, personal computer, microprocessor-based entertainment device, peer device or other common network node, and generally includes many or all of the elements described with respect to the computer. The logical connections in the figure include a local area network (LAN) and a wide area network (WAN). Such network environments are commonplace in offices, corporate computer networks, intranets, and the Internet.

  When used in a LAN network environment, the computer is connected to the local network through a net winder fader or adapter. When used in a WAN networking environment, the computer typically includes a modem or is connected to a communication server on the LAN or has other means for establishing communications over the WAN, such as the Internet. In a network environment, program modules written for a computer, or portions thereof, may be stored on a remote memory storage device. Of course, the network connections described herein are exemplary and any other means for establishing a communication link between the computers may be used.

  Although the invention has been described with respect to particular embodiments, it will be appreciated by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the scope thereof. Accordingly, the invention is not limited to the specific embodiments disclosed, but is intended to include all embodiments that fall within the scope of the appended claims.

DESCRIPTION OF SYMBOLS 100 Energy source system 110 Laser beam 115 Work piece 120 Laser apparatus 130 Laser power supply 140 Filler wire 150 Filler wire feeder 160 Contact tube 170 Power supply 195 Current controller 700 Heating system 707 Contact chip assembly 710 Switch 800 Manufacturing current waveform 900 Contact chip assembly 910 Contact chip 1000 system 1010 contact chip assembly 1200 system 1210 power supply 1230 CPU / controller 1240 voltage detection circuit 1250 power module 1300 system 1305 contact chip assembly 1600 substrate 1610 substrate surface 1900 welding material 2000 contact chip assembly, welding material 2010 welding material 2020 adhesion material 2040 contact tip 2050 switch 2100 adhesion material

Claims (18)

A high energy device that irradiates a surface of the workpiece with a high energy discharge to form first and second molten pools on the surface of the workpiece;
A first power supply for supplying a first heating signal to a first wire, wherein the first heating signal includes a plurality of first current pulses, and the first current of the first heating signal. A first power source such that each pulse forms a molten drop at the tip of the first wire, which is deposited in the first molten pool;
A second power supply for supplying a second heating signal to the second wire, wherein the second heating signal includes a plurality of second current pulses, and the second current of the second heating signal. A second power source such that each pulse forms a molten drop at the tip of the second wire, which is deposited in the second molten pool;
In addition manufacturing system including
Each of the first current pulses reaches a peak current level after the tip of the wire contacts the first molten pool;
The first heating signal has no current between the plurality of first current pulses,
The tip of the first wire does not contact the first molten pool between successive peak current levels of the first current pulse;
The first power source controls the first heating current so that no arc is generated between the first wire and the workpiece during the first current pulse;
The additive manufacturing system, wherein the first and second molten pools are different molten pools.   The system of claim 1, wherein each of the different weld pools is adjacent to each other on the workpiece.   2. The system of claim 1, wherein the first and second wires are arranged in a line in the direction of movement, the second wire follows the first wire, and the second wire is A system positioned to deposit on a layer formed by the first wire.   The system of claim 1, wherein the first wire has a different composition than the second wire.   The system of claim 1, wherein the first wire has a first wire feed rate and the second wire is a second wire feed that is different from the first wire feed rate. A system characterized by having a speed.   The system of claim 1, further comprising a first contact tip for the first wire and a second contact tip for the second wire, wherein the first and second contact tips are A system for supplying said first and second heating signals to said first and second wires, respectively, wherein said first and second contact tips are movable relative to each other.   The system of claim 1, further comprising a first contact tip for the first wire and a second contact tip for the second wire, wherein the first and second contact tips are Supplying the first and second heating signals to the first and second wires, respectively, wherein the first wire has a first protruding distance different from a second protruding distance of the second wire; A system characterized by comprising.   The system of claim 1, wherein the first contact tip for the first wire and the second contact tip for the second wire are the first and second heating signals, respectively. First and second contact tips for supplying the first and second wires, and a contact tip assembly for interconnecting the first and second contact tips, the first and second wires A contact tip assembly that is rotatable with respect to the direction of wire movement.   The system of claim 1, wherein the first power source monitors the voltage of the first heating signal when the first wire is in contact with the first molten pool and arcs the voltage. A system characterized by comparing with a detected voltage level. Irradiating a surface of the workpiece with a high energy discharge to form first and second molten pools on the surface of the workpiece;
Supplying a first heating signal to the first wire, wherein the first heating signal includes a plurality of first current pulses, each of the first current pulses of the first heating signal; Forming a molten droplet at the tip of the first wire, which is deposited in the first molten pool;
Supplying a second heating signal to a second wire, wherein the second heating signal includes a plurality of second current pulses, each of the second current pulses of the second heating signal. Forming a molten droplet at the tip of the second wire, which is deposited in the second molten pool;
In an additive manufacturing method including:
Each of the first current pulses reaches a peak current level after the tip of the wire contacts the first molten pool;
The first heating signal has no current between the plurality of first current pulses,
The tip of the first wire does not contact the first molten pool between successive peak current levels of the first current pulse;
The first heating current is controlled so that no arc is generated between the first wire and the workpiece during the first current pulse;
The additive manufacturing method, wherein the first and second molten pools are different molten pools.   11. The method of claim 10, wherein each of the different weld pools is adjacent to each other on the workpiece.   11. The method of claim 10, wherein the first and second wires are arranged in a line in the direction of movement, the second wire follows the first wire, and the second wire is A method characterized in that it is positioned to deposit on a layer formed by said first wire.   11. The method of claim 10, wherein the first wire has a different composition than the second wire.   12. The method of claim 10, wherein the first wire is fed at a first wire feed rate and the second wire is a second wire feed different from the first wire feed rate. A method characterized by being fed at a speed.   11. The method of claim 10, wherein the first wire is passed through a first contact tip and the second wire is passed through a second contact tip, the first and first A second contact tip further comprising: supplying the first and second heating signals to the first and second wires, respectively; and moving the first and second contact tips relative to each other. A method characterized by comprising.   11. The method of claim 10, wherein the first wire is passed through a first contact tip and the second wire is passed through a second contact tip, the first and first The second contact tip further includes supplying the first and second heating signals to the first and second wires, respectively, wherein the first wire is a second protrusion of the second wire. The method is characterized in that the first protrusion distance is different from the distance degree.   11. The method of claim 10, wherein the first wire is passed through a first contact tip and the second wire is passed through a second contact tip, the first and first A second contact tip for supplying the first and second heating signals to the first and second wires, respectively, and the second contact tip with respect to the first contact tip during the additional manufacturing. And further comprising the step of rotating.   11. The method of claim 10, wherein monitoring the voltage of the first heating signal when the first wire is in contact with the first molten pool and comparing the voltage to an arc detection voltage level. And further comprising the step of:

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