JP4080716B2 - Pulse current welding method for small joint surface - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a pulse current joining method using the principle of pulse current sintering method, a joining apparatus thereof, and a joined body joined by such a joining method, and more specifically, a thin-walled pipe, a tube, or a small chip (small size). (Chips with circular, polygonal, or other shapes) or thin rods or wires, or the joining of small members such as those with large areas. The present invention relates to a bonding method, a bonding apparatus, and a bonded body that are used.
[0002]
[Prior art]
Joining members with small joint surfaces to each other, such as when joining the ends of thin pipes and joining them at the abutting end, or joining the end face of a thin bar, wire, or small chip to another member As a conventional method, (1) a method in which the end portions to be joined are locally heated and melted and the welding auxiliary material is also melted, thereby joining them with the welding auxiliary material interposed therebetween, and (2) joining together. A method of locally irradiating a high energy beam such as a laser beam or an electron beam around the power part to locally melt the part and thereby joining the members to each other; and (3) different from the above welding auxiliary material Commonly used is a method in which a brazing material (an alloy such as Cu or Ag or an amorphous metal) made of a material different from the member to be joined is melted and joined between the joining surfaces in a vacuum atmosphere or an inert atmosphere. There was.
[0003]
However, in the joining method of the above (1), (a) a problem that a welding auxiliary material must be used, (b) a problem that the base material of the member changes in quality because the member to be joined is locally dissolved, and (C) There is a problem that the material of members that can be joined to each other is limited. Further, in the joining method of (2), the problem of requiring a welding auxiliary material as in (a) is eliminated, but the members to be joined are dissolved locally as in (b) and (c). Therefore, there is a problem that the base material of the member is deteriorated, and there is a problem that the material of the members that can be bonded to each other is limited. Furthermore, (d) a high bonding strength can be obtained because the bonding is locally performed in the peripheral portion. There is a problem that cannot be done. Furthermore, in the joining method (3), since the joining is performed through the above (a) to (c) and the wax material, not only the material of the member that can be joined is limited, but also sufficient heat resistance and joining strength are obtained. There is a problem that can not be.
[0004]
[Problems to be solved by the invention]
By the way, the development of various devices and the miniaturization of such devices have progressed due to the advance of technology, and new fields of use of materials have been developed. In addition, it has been required to be firmly bonded with a small bonding area such as a small chip (a small area circular, polygonal, or other shape chip). For example, when connecting to a thin-walled stainless steel pipe of sufficient length with a sufficient sealing strength, a non-magnetic pipe, solid bar (circular cross section, polygon, other shapes) In the same way, when connecting thin magnetic pipes, solid bars (bars with circular, polygonal or other shapes), tungsten carbide, cobalt carbide For example, when the material and the iron-based material are used in combination, or when the copper-based material and the iron-based material are used in combination.
[0005]
In recent years, using the principle of pulse-current pressure sintering (including discharge plasma sintering, discharge sintering, or plasma activated sintering) performed by applying a pulsed current, the powder has a predetermined bulk rather than powder. A technique for joining members having large joining surfaces is being developed. However, in a joining apparatus using this pulse current pressurization and sintering method, it is necessary to carry out with a relatively large pressure applied to the material. For this reason, for example, when the end surfaces of the thin-walled pipes are brought into contact with each other and joined, the joining surfaces of the members to be joined together are small, and when a large force is applied, the members cannot be used. In order to solve such a problem, an outer shape, a core type or a jig for preventing buckling must be used.
However, when using a mold or jig, each time the shapes and dimensions of the members to be joined are different, a die or jig that matches the shape and dimensions of the members to be joined must be prepared. There are major problems with mass production and practicality, such as the problem of complicated work, the need to energize the mold or jig, the problem of long joining time and power consumption, and the problem of high joining cost.
[0006]
The problem to be solved by the present invention is based on the principle of pulsed current pressure sintering including discharge plasma sintering, discharge sintering or plasma activated sintering, and is suitable for joining members having small joint surfaces. Another object of the present invention is to provide a pulse current joining method.
Another problem to be solved by the present invention is that mass production and high practicality can be achieved by controlling the pressure applied to the members to be joined with high precision by a pressing device to prevent the occurrence of buckling, bending, etc. of the members to be joined. It is to provide a pulse current joining method.
[0007]
[Means for Solving the Problems]
In one aspect of the present invention, a plurality of members having small joining surfaces to be joined to each other are placed in a chamber maintained in a desired atmosphere. small It is sandwiched between a pair of energizing electrodes in a state where the joint surfaces are in contact with each other, and a pulse current of a desired voltage and current is supplied to the plurality of members via the pair of energizing electrodes. small In the pulse energization joining method for small joint surfaces that join at the joint surface,
Pressing the plurality of members with a desired first pressing force before starting energization,
After the start of energization, the temperature in the chamber reaches a temperature determined by the material and dimensions of the plurality of members to be joined, and then presses the plurality of members with a second pressing force determined by the material and dimensions,
The plurality of members Solid layer diffusion bonding without causing buckling, bending deformation, etc. Temporary joint In Is configured to do. The second pressing force may be a variable pressing force that changes as appropriate.
In the above-described pulse energization joining method for small joining surfaces, the pressing with the second pressing force may be controlled by always detecting the pressing force applied to the member with a pressure sensor and feeding it back. Above small The joining surface may be polished to a mirror surface. In addition, the pulse joining method for small joining surfaces may further include subjecting the temporarily joined member to heat treatment at a temperature and time determined by the material and dimensions of the member.
Furthermore, in the pulse energization joining method for small joining surfaces, the heat treatment may be performed by passing a heat treatment current through the energizing electrode in the chamber subsequent to the temporary joining, or a plurality of temporarily joined temporary works. The joined body may be put together by a heat treatment furnace.
[0009]
【Example】
Next, with reference to the drawings, an embodiment of a joining apparatus for carrying out the pulse current joining method for small joining surfaces according to the present invention will be described.
1 to 3, a pulse energization joining device for small joint surfaces (hereinafter simply referred to as an energization joining device) 1 according to the present embodiment is shown. This energization joining apparatus 1 uses the principle of pulse electric current sintering method including discharge plasma sintering, discharge sintering or plasma activated sintering, etc. Do not use a sintering die (die, punch, etc.). The energization joining device 1 is attached to the frame device 10, the movable table device 20 supported so as to be movable in the vertical direction (in FIG. 1) with respect to the center portion (in FIG. 1) of the frame device 10, and the movable table device 20. The lower energizing electrode assembly 31, the pressing device 40 for moving the movable table device up and down, the upper energizing electrode assembly 32 attached to the upper part of the frame device 10, And a housing assembly 50 that defines a chamber that creates a desired atmosphere (for example, a vacuum atmosphere or an inert gas atmosphere) around the member. The overall operation of the energization joining device of this embodiment is controlled by the control device 60 (FIG. 3), and a DC pulse current for joining is supplied from the power supply device 70 (FIG. 3).
[0010]
The frame device 10 includes a box-shaped lower frame 11, a lower support plate 12 fixed to the upper portion of the lower frame 11, and a plurality of (in this embodiment, lower support plate) attached to the lower support plate 12 by a known method. 4) of support columns 13 disposed in the vicinity of the four corners, and an upper support plate 14 attached to the upper end of the support column 13 by a known method. The lower support plate 12 is formed with four through holes, and a bearing member 121 is mounted in the through holes. In each bearing member 121, guide shafts 22 attached to the four corners of the movable table 21 of the movable table device 20 by a known method and extending downward are slidably inserted. Therefore, the movable table 21 is guided by the guide shaft 22 and the bearing 122 so as to be movable only in the vertical direction.
[0011]
A pressing device 40 is disposed and fixed in the lower frame 11. The pressing device 40 includes a ball screw device 41 having a known structure and function extending in a vertical direction in a vertical direction, an electric motor 42 as a drive source for supplying an input to an input shaft (not shown) of the ball screw device 41, And a transmission mechanism 43 that gives the rotation output of the electric motor 42 to the ball screw device 41. The electric motor 42 is preferably a stepping motor capable of controlling a minute rotation angle with high accuracy. The electric motor 42 is connected to a control device 60 and its rotation is controlled under the control of the control device. A guide plate 24 is attached to the vicinity of the upper end (in FIG. 1) of the output shaft 411 of the ball screw device 41, and a plurality of guide rods 25 attached to the movable table 21 and extending downward are movable relative to the guide plate 24. It is guided to. The axis of the ball screw device 41 and the axis of the lower energizing electrode assembly 31 are made to coincide with the axis 0-0 of the entire device. Between the movable table 21 and the output shaft 411, a pressure sensor 61 of a control device 60 that controls the operation of the energization joining device is disposed. The pressure sensor 61 may have a known structure and function. Therefore, the axial pressing force applied to the movable table 21 by the pressing device 40 is detected by the pressure sensor 61. The output shaft 411 of the ball screw device is prevented from rotating by the action of the guide plate and the guide rod.
[0012]
A lower energizing electrode assembly 31 is insulated and fixed on the upper surface of the movable table 21 with respect to the movable table via an insulating mounting plate 35. The attachment plate 35 and the lower end of the lower energizing electrode assembly 31 are fixed by a plurality of known set screws, and the attachment plate 35 is fixed to the movable table 21 by a known set screw. The lower energizing electrode assembly 31 includes a cylindrical lower energizing electrode 33 made of a hard and tough material, for example, stainless steel. The lower energizing electrode 33 can be connected to the power supply device 70 (FIG. 3) via a cable and switch device 71 (FIG. 3). The switch device 71 may constitute a part of the power supply device, or may have the same structure as the switch mechanism disclosed in Japanese Patent Application No. 2000-284771 “Current Supply Device for Pulsed Current Sintering Machine” by the present applicant. A cooling passage (not shown) for flowing a cooling fluid is formed in the lower energization electrode 33, and the cooling fluid is circulated through the cooling passage via a pair of supply / discharge pipes (only one shown in FIG. 1) 331. It has become so. The attachment plate 35 may be entirely made of an insulating material, or may be a metal plate whose surface is subjected to an insulation treatment.
[0013]
A lower housing portion 51 of the housing assembly 50 is provided outside the lower energizing electrode 33 so as to be relatively movable with respect to the lower energizing electrode 33. The lower housing portion 51 includes a bottom wall member 511 slidably attached to the outer periphery of the lower energizing electrode, an inner peripheral wall member 512 and an outer peripheral wall member fixed to the bottom wall member so as to be separated from each other and sealed with respect to the bottom wall member. 513 and an annular end plate 514 fixed to the upper ends of the inner and outer peripheral wall members. A contact surface of the bottom wall member 511 with respect to the lower energization electrode is provided with a seal member (not shown) having a known structure, and seals a gap between them. A drive rod 53 is attached to the bottom wall member 511 so as to be slidably supported by a bearing 123 mounted in a through hole of the lower support plate 12. The drive rod is driven by a rack and pinion device and an electric motor (not shown) for rotating the pinion. Thus, the lower housing portion 51 can be moved relative to the lower energizing electrode. Reference numeral 55 denotes a stopper which is attached to the movable table and restricts the lowering of the lower housing portion 51, and is provided at two locations in the diametrical direction about the axis 0-0. Reference numeral 57 denotes an observation window made of heat-resistant glass.
[0014]
A lower energizing electrode assembly 32 is fixed to the lower surface of the upper support plate 14 via a mounting plate 36 and an insulating plate 38. The fixing between the insulating plate 38 and the upper end of the lower energizing electrode assembly 32, the fixing between the insulating plate 38 and the mounting plate 36, and the fixing between the mounting plate 36 and the upper support plate 14 are performed by a plurality of known set screws. The upper energizing electrode assembly 32 has a cylindrical upper energizing electrode 34 made of stainless steel. The upper energizing electrode 34 can be connected to the power supply device 70 via a cable. A cooling passage (not shown) for flowing a cooling fluid is formed in the upper energizing electrode 33, and the cooling fluid is circulated through the cooling passage via a pair of supply / discharge pipes (only one shown in FIG. 1) 341. It has become so.
[0015]
An upper housing portion 52 of the housing assembly 50 is disposed outside the upper energizing electrode 34. The upper housing portion 52 includes a top wall member 521 that is sealed and attached to the outer periphery of the lower energizing electrode by a known method, and an inner peripheral wall member that is fixed to the top wall member 521 in a sealed manner with respect to the bottom wall member. 522 and an outer peripheral wall member 523, and an annular end plate 524 fixed to the lower ends of the inner and outer peripheral wall members. The top wall member 521 is fixed to the upper support plate 14 via a plurality of connecting rods 54 (four in this embodiment, but only one is shown) fixed to the upper support plate 14. Reference numeral 56 denotes a pipe attached to the inner peripheral wall member 522 and the outer peripheral wall member 523, and is connected to an atmosphere control device (not shown) for making a vacuum atmosphere or an inert gas atmosphere via a conduit (not shown). An annular groove is formed in at least one of the upper surface of the end plate 514 of the lower housing portion 51 and the lower surface of the end plate 524 of the upper housing portion 52, and an O-ring seal is provided in the groove. Air leakage between them can be prevented. As shown in FIG. 3, a pressure sensor 62 and a temperature sensor 63 are provided in the upper housing portion 52, and are defined by the lower housing portion 51 and the upper housing portion 52 by the pressure sensor and the temperature sensor. The gas pressure and temperature in the chamber C can be detected. The pressure sensor 62 and the temperature sensor 63 are connected to the control device 70 so that detection signals can be input to the control device. Note that pressure control combined with temperature feedback may be performed.
[0016]
[Example 1]
Next, the case where the thin-walled pipes M1 and M2 as shown in FIG. 4 [A] are joined with their end faces butted using the above-described current joining apparatus 1 will be described. Here, the pipe M1 is a pipe made of non-magnetic stainless steel (SUS304), and the pipe M2 is a pipe made of magnetic stainless steel (SUS430), both of which have a length L. ₁ = 30 mm, inner diameter d ₁ = 8 mm, outer diameter d ₂ = 10mm, thickness is t ₁ = 1 mm. In this case, the end surfaces of the pipes M1 and M2, which are joined to each other, that is, the upper end surface M1e of the pipe M1 and the lower end surface M2e of the pipe M2, are cut so as to be in uniform contact over the entire surface. Preferably, it is polished to a mirror surface. After the two pipes prepared in this way and having the end faces abutted are set on the upper end face of the lower energizing electrode 33 using, for example, a V-groove structure alignment jig or the like, the control device 60 operates the pressing device 40. Thus, the movable table 12 is raised, and a pipe is sandwiched between the lower energizing electrode assembly 31 and the upper energizing electrode assembly 32. At this time, the pressing force of the pressing device 40 is adjusted so that the initial pressing force is pressed with a force of, for example, 1 to 3 megapascals so that the contact surface can be easily adjusted. In this state, the lower housing portion 51 is raised to bring the end plate 514 into contact with the end plate 524 of the upper housing portion 52, and the chamber C sealed from the outside around the M1 and M2 members to be joined is defined by the housing. To do.
[0017]
In this state, the atmosphere control device is operated to make the chamber C have a desired atmosphere. In this case, the chamber is evacuated to a vacuum state, for example, about 6.7 Pascals (Pa) (5 × 10 5 ^-2 torr). After the evacuation of the chamber is completed, the switch device 71 is turned on by a command from the control device 60, and 300 to 800 at 6 to 12 volts (V) is applied to the pipes M1 and M2 from the power supply device 70 through the vertical conduction electrode assembly. An ampere (A) DC pulse current is passed. As the current flows, the pipe generates heat and becomes hot, and since the upper and lower sides are mechanically fixed, distortion in the axial direction occurs due to thermal expansion, the applied pressure gradually increases, and the pipe is axially moved with high pressing force. The pipe will buckle when pressed against. For this reason, after fixing the pipe, the pressing force applied to the pipe by the pressing device 40 is reduced to, for example, 0.5 to 1.0 megapascal (MP), and energization of the pulse current is started. Thereafter, the pressing force is feedback-controlled based on the detection signal from the pressure sensor 61 to hold the pressing force. The feeding mechanism of the energizing and pressing shaft may incorporate a program that fast-forwards to about 1 to 2 mm before the upper end surface of the pipe and decelerates until it comes into contact with the rear end surface. Since both pipes are joined in a short time of about 2 to 5 minutes from the start of energization to the pipe, the switch device is turned off to stop energization. The principle of this joining is as follows. When a direct current pulse current is passed, the contacting interface portion having a high contact resistance is heated to a high temperature by Joule heating. Further, the whole is Joule-heated by the resistance value of the material itself. In addition, high pressure is generated at the contact interface of the members stacked one above the other due to plastic deformation and thermal expansion caused by the vertical uniaxial pressure. Furthermore, an electric field is generated along the direction of on-off pulse current flow, and electric field diffusion occurs. It is considered that this electric field diffusion effect and the above-described mechanical pressure of thermal diffusion contribute to the solid phase diffusion bonding and bring about the orientation of the metal crystal structure. Since this joining is not necessarily performed with sufficient joining strength, it is called temporary joining here, and what was temporarily joined is called a temporary joined body. After energization is stopped, the chamber is returned to atmospheric pressure, and the lower housing part is lowered so that the temporary joined body sandwiched between the upper and lower energized electrodes can be taken out. Thereafter, the movable table is lowered, the temporary joined body is taken out between the upper and lower energized electrodes, and the temporary joining is completed. In the above case, the temporary joined body is cooled by natural cooling. However, when forced cooling is desired, the cooled inert gas is supplied into the chamber after the energization is stopped, or the cooling having the endothermic structure member is performed. A stage may be separately provided and cooled. In addition, although Example 1 is the case of the member piled up and down, you may join a some pipe and a solid round bar inside and outside a coaxial cylinder pile shape (Baumkuchen shape or concentric circle shape).
[0018]
If the area of the joint surface is small, such as joining thin pipes as described above, joining rods or wires having a small diameter, or joining rods, wires or thin pipes and plates, a large force is required. If it is added, the member to be joined will buckle, bend, etc. even at room temperature, and if the member to be joined generates heat and becomes high temperature, it will buckle with a smaller pressing force. For this reason, various control programs (control programs that determine the pressing force decrease start temperature, pressing force, energization time, etc.) according to the dimensions (length, outer diameter, thickness, etc.) and material of the members to be joined are created in advance. In addition, the pressure device increases / decreases feedback control by the pressing device 40 in accordance with the control program. The pressing force by the pressing device can be controlled with a value as close to zero as possible. A flowchart of such feedback control is shown in FIG.
[0019]
The joining of the two pipes performed by the energization joining device is a temporary joining. Depending on the purpose of use of the pipe, there may be a case where the joining strength is about the temporary joining. In that case, the temporarily joined pipes M1 and M2 are taken out from the energization joining apparatus as a temporarily joined body M3 shown in FIG. When the two pipes are joined with high joining strength, heat treatment is performed under the following conditions.
Heat treatment temperature 900 ° C-1000 ° C
Heat treatment time 30 minutes to 90 minutes
The heat treatment conditions are for a temporary joined body in which the thin stainless steel pipe is temporarily joined as a member to be joined, and varies depending on the size and material of the member to be joined.
[0020]
Next, the case where the pipes M1 and M2 temporarily joined as described above (and hence the temporary joined body M3 here) is subjected to heat treatment using the above-described electrical joining apparatus will be described. After energization for temporary bonding is completed, the vacuum atmosphere in the chamber C is kept as it is, or the temperature in the chamber C is suitable for the heat treatment temperature by flowing an inert gas into the chamber and cooling it. After the temperature is lowered, a DC current of 500 to 1000 amperes is applied for about 10 to 30 minutes from the power supply device 70 at a heat treatment current for maintaining the heat treatment temperature, that is, 5 to 20 volts. In this case, the current value is feedback-controlled by a temperature sensor provided in the chamber so that the temperature in the chamber is maintained at the heat treatment temperature. By this heat treatment, both pipes are completely joined (main joining). After the heat treatment is completed, after waiting for cooling in the chamber C (either natural cooling or forced cooling), the lower housing part is lowered and the movable table is lowered to take out the main joined pipe for use. Usually, since the heat treatment time is much longer than the temporary bonding time, it is inefficient to perform the heat treatment using the energization bonding apparatus as described above. Therefore, performing such heat treatment is suitable for single items or small-scale production.
[0021]
In FIG. 6, another embodiment of the current bonding apparatus of the present invention is shown. This energization joining apparatus further includes a heat treatment unit 80 for performing heat treatment. This heat treatment section may be a heat treatment furnace having a known structure available on the market. When heat treatment is performed in this heat treatment furnace, when a plurality of pipes temporarily joined by the current-carrying joining apparatus 1 are collected, the pipes are collectively put into a heat treatment furnace and heat treatment is performed at once. This is because the temporary bonding can be performed in a few minutes, but the heat treatment takes several tens of minutes. Therefore, by performing the heat treatment on a plurality of temporarily bonded bodies collectively, the efficiency can be improved. Suitable for mass production.
[0022]
The energization joining apparatus may further include a conveying device 90 that automatically supplies the temporarily joined member, that is, the temporarily joined body, to the heat treatment unit 80. The transfer device is configured such that a robot apparatus 91 having a known structure for taking out a temporary joined body from between upper and lower energized electrodes on the energizing joining apparatus 1 and a plurality of temporary joined bodies taken out by the robot apparatus 91 are collected in the heat treatment unit 80. And a conveyor 92 to be sent to the vehicle. The robot device 91 includes an arm 911 that can swing within a range of an angle θ, and a chuck 912 attached to the tip of the arm. By performing a heat treatment on the separately provided heat treatment portion, a plurality of temporary joined bodies can be heat-treated in a batch manner, so that they can be joined efficiently. Therefore, it is suitable for manufacturing a large number of joined bodies made of the same product. Although not shown in the drawing, the members to be joined are supplied in a state of being stacked one above the other by a supply conveyor provided in the middle of the swing range of the arm 911, and are gripped by the chuck and automatically between the upper and lower energizing electrodes. It may be supplied automatically and pressed by these energizing electrodes while being held by the chuck.
Although not shown, an apparatus may be provided that performs automatic conveyance from the TP magazine to the bonding apparatus, from the bonding apparatus to the heat treatment furnace, and further from the heat treatment furnace to the cooled or processed bonded article magazine.
[0023]
[Example 2]
A case where the end face of the thin wire N1 and one surface of the plate N2 as shown in FIG. 7A will be described. Here, the wire N1 is made of molybdenum and has a length L. ₂ = 25 mm, outer diameter d _Three = 5 mm, the plate material N2 is made of tungsten, and the diameter d _Four = 30mm and wall thickness is t ₂ = 5 mm disk. In this case, the end surface of the wire N1 and the surface of the plate N2 that are in contact with each other are processed so as to be in uniform contact. Preferably, it is polished to a mirror surface. The wire material and the plate material thus prepared and butted against each other were first temporarily joined by the energization joining apparatus 1 in the same manner as in Example 1. At that time, it was pressed by the upper and lower energizing electrodes with an initial pressing force of 5 megapascals.
[0024]
In this state, the atmosphere control device is operated to evacuate the chamber C to obtain a vacuum state (5 × 10 5 ^-2 Torr), the preset pressure set by the pressing device was set to 2 megapascals, and a DC pulse current of 200 to 600 amperes (A) was applied to the wire and plate through the vertical conducting electrode assembly at 3 to 12 volts (V). As the current flowed, the pipe heated up and became hot, so we measured it with a non-contact infrared radiation thermometer. The pressing force was maintained by feedback control of the pressure between 1 and 2 megapascals until the temperature of the joined portion reached 1350 ° C. The energization was stopped 5 minutes after the energization started. As a result, a temporary joined body N3 of wire and plate as shown in FIG. 7B was completed. This temporary joined body N3 was heat-treated using a vacuum heat treatment furnace of the heat treatment part 80 for a heat treatment temperature of 1180 ° C. and a heat treatment time of 40 to 60 minutes. By this heat treatment, the joining of the wire and the plate became complete.
In the above embodiment, only the joining of the stainless steel thin pipe and the joining of the molybdenum wire and the tungsten plate have been described, but in addition to joining of various members having a small joining area, joining of members of various materials. It is possible to use the method and apparatus of the present invention. For example, as shown in FIG. 8A, when joining a plurality of small-diameter columnar or cylindrical chips O2 to the substrate O1, as shown in FIG. 8B, the small gear P2 is connected to the disk P1. As shown in FIG. 8C, when the cam member Q2 is joined to the substrate Q1, as shown in FIG. 8D, a plurality of small cams R1 to R8 having a plurality of different shapes are joined. When R3 is joined adjacently, as shown in FIG. 8E, there is a case where a small part S2 is joined to the block material S1.
[0025]
【The invention's effect】
According to the present invention, the following effects can be obtained.
(B) The members of small joint areas, such as thin pipes, can be easily buckled in a fully sealed state over the entire contact surface by the pulse current welding method in which solid phase diffusion bonding is used to join the members. It is possible to mass-produce high-quality bonded parts without causing bending deformation and the like and having the same strength as the base material.
(B) Members of different or similar materials that cannot be joined by conventional joining methods can be easily joined together.
(C) Since pedestal-shaped parts can be manufactured by pulse-electrically joining small-piece members to the substrate material without cutting into complex shapes by cutting (milling, electrical discharge machining, etc.) from block-shaped materials, Significant process reduction and cost reduction.
(D) It can be easily made with an integral shape or undercut shape of a flat part and a protruding part that have a right angle or acute angle that cannot be cut with an end mill edge, and the shape design is more than that produced by cutting from an integral member. Increases freedom.
(E) Solid phase diffusion bonding parts can be easily mass-produced in a short time at a low cost.
(F) Compared to brazed and welded parts, it is possible to produce parts that are more reliable in terms of organization and mechanical properties.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a pulse current welding apparatus for small joint surfaces according to the present invention.
FIG. 2 is a cross-sectional view of a small-junction-surface pulse energization bonding apparatus viewed along line AA in FIG.
FIG. 3 is a diagram showing a connection relationship between electricity and a control system of the pulse energization joining device for a small joining surface in FIG. 1;
4 is a perspective view showing a member and a temporary joined body of the first embodiment that are joined using the pulse current joining apparatus for small joining surfaces of FIG. 1; FIG.
5 is a flowchart showing feedback control of the pressing force of the pulsed joining apparatus for small joining surfaces of FIG. 1. FIG.
FIG. 6 is a view showing a modification of the pulse energization bonding apparatus for small bonding surfaces according to the present invention.
7 is a perspective view showing a member and a temporary joined body of a second embodiment that are joined by using the pulse energization joining device for small joining surfaces of FIG. 1. FIG.
FIG. 8 is a schematic perspective view showing another example of joining using a pulse energization joining device for small joining surfaces.
1 Pulse current welding equipment
10 frame device 20 movable table device
21 movable table 30 energizing electrode device
31 Lower conducting electrode assembly 32 Upper conducting electrode assembly
33 Lower conducting electrode 34 Upper conducting electrode
40 pressing device 50 housing
51 Lower housing part 52 Upper housing part
60 control device 61 pressure sensor
62 Pressure sensor 63 Temperature sensor
70 Power supply device 71 Switch device
80 Heat treatment section 90 Transport device

Claims (6)

A plurality of members having small joining surfaces to be joined to each other are placed in a chamber maintained in a desired atmosphere and sandwiched by a pair of energizing electrodes in a state where the small joining surfaces are in contact with each other, and the pair of members are sandwiched between the plurality of members. In the pulse energization joining method for small joint surfaces in which a pulse current of a desired voltage and current is passed through the energizing electrode and joined at the small joint surface,
Pressing the plurality of members with a desired first pressing force before the start of energization of the pulse current,
After energization of the pulse current, after the temperature in the chamber reaches a temperature determined by the material and dimensions of the members to be joined, the members are pressed with a second pressing force determined by the material and dimensions. And
A pulse energization joining method for small joining surfaces, characterized in that the plurality of members are bonded by solid phase diffusion bonding without causing buckling, bending deformation or the like to form a temporary joined body. In the pulse energization joining method for small joint surfaces according to claim 1,
The pulse energization joining method for small joining surfaces, in which the pressing with the second pressing force is detected by a pressure sensor that is constantly applied to the member and fed back to control.   The pulse energization joining method for small joint surfaces according to claim 1 or 2, wherein the small joint surface is polished into a mirror surface. In the pulse energization joining method for small joint surfaces according to claim 1, 2, or 3,
A pulse energization joining method for small joining surfaces, characterized in that the temporarily joined member is heat-treated at a temperature and time determined by the material and dimensions of the member. In the pulse energization joining method for small joint surfaces according to claim 4,
A pulse energization joining method for small joining surfaces, wherein the heat treatment is performed by passing a heat treatment current through the energizing electrode in the chamber following the temporary joining. In the pulse energization joining method for small joint surfaces according to claim 4,
A pulse energization joining method for small joint surfaces, wherein the heat treatment is performed in a heat treatment furnace by combining the plurality of temporarily joined temporary joined bodies.

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