CN113695592A

CN113695592A - Additive manufacturing device based on resistance heating wire material and laser compounding and test method

Info

Publication number: CN113695592A
Application number: CN202110997107.8A
Authority: CN
Inventors: 李素丽; 马恺悦; 杨来侠
Original assignee: Xian University of Science and Technology
Current assignee: Xian University of Science and Technology
Priority date: 2021-08-27
Filing date: 2021-08-27
Publication date: 2021-11-26

Abstract

The invention provides a material increase manufacturing device and a test method based on resistance heating wire material and laser compounding, wherein resistance heating and laser are used as heat sources, the material increase manufacturing is carried out by adopting the resistance heating and laser compounding material increase method, the material increase manufacturing device comprises a laser deposition system, an electric heating system, a wire feeder, a substrate, a movable machine tool and a controller, the material increase manufacturing device is effectively monitored and controlled through the controller, a current sensor and a voltage sensor display real-time current and voltage in the deposition process on the controller through an acquisition card, the current and voltage condition in the printing process is effectively controlled, and the intelligence of material increase manufacturing is effectively improved.

Description

Additive manufacturing device based on resistance heating wire material and laser compounding and test method

Technical Field

The invention relates to the field of additive manufacturing and rapid prototyping, in particular to an additive manufacturing device and a test method based on compounding of resistance heating wire materials and laser.

Background

As a new processing technology, compared with the traditional material reduction processing technology, the additive manufacturing technology has the advantages of short product manufacturing period, high production efficiency, no need of a die, low cost, high material utilization rate and the like. In the existing additive manufacturing method for the metal material, the metal material is heated mainly by adopting methods such as laser, electron beam heating, electric arc heating and the like, so that the rapid forming and additive manufacturing of parts are completed. However, in all of these molding methods, the material melting amount is small, and the molding efficiency is low.

At present, laser additive manufacturing technologies are mainly divided into two mainstream technologies, namely selective laser melting based on powder spreading and direct laser melting deposition based on powder feeding, but sample pieces formed by the two technologies have large residual stress, so that the sample pieces are cracked and warped and deformed, and in the laser additive manufacturing technologies, the parts have large residual stress due to high cooling rate and uneven temperature field distribution.

Disclosure of Invention

The invention provides a device and a test method for additive manufacturing based on compounding of resistance heating wire materials and laser, aiming at the problem that the laser additive manufacturing technology in the prior art is mainly divided into two main technologies of selective laser melting based on powder laying and direct laser melting deposition based on powder feeding, which have larger residual stress and cause cracking and buckling deformation of a sample.

The invention is realized by the following technical scheme:

a material increase manufacturing device based on compounding of resistance heating wire materials and laser comprises a laser deposition system, an electric heating system, a wire feeder, a substrate, a movable machine tool and a controller, wherein the controller is respectively connected with a power supply of the laser deposition system, the electric heating system and the wire feeder; the laser deposition system and the wire feeder are respectively connected to the movable machine tool through a fixed connecting rod;

the electric heating system comprises a heating device, a programmable power supply, a current sensor, a voltage sensor, a collecting card and a heating power supply; the heating device is assembled at the bottom end of the substrate, one electrode of the programmable power supply is connected to the substrate, the other electrode of the programmable power supply is connected to the wire feeder, a metal wire is arranged in the wire feeder, and when the metal wire contacts the substrate through the wire feeder, a loop is formed after the programmable power supply is electrified; the acquisition card is connected to a circuit of a programmable power supply through a current sensor and a voltage sensor, and the heating power supply is connected to a heating device;

the laser deposition system and the wire feeder synchronously move on the substrate through the mobile machine tool, laser output by the laser deposition system is arranged towards the metal wire, and the metal wire is printed on the substrate to form an additive sample through heating of the heating device;

the input end of the controller is connected with the signal input module, and the output end of the controller is respectively connected with the power supply control module and the switch control output module; the signal input module is respectively connected with the current sensor and the voltage sensor through the acquisition card; the power supply control module is respectively connected with a programmable power supply and a heating power supply; and the switch control output module is connected with the laser deposition system.

Preferably, still include the argon gas device, the argon gas device is connected to on the removal lathe through fixed link, and argon gas device and laser deposition system and send a quick-witted synchronous motion on the base plate, and the metal silk material on the base plate is aimed at to the output of argon gas device for the metal silk material is deposited.

Preferably, the laser deposition system comprises a laser and a hydro-energy device, wherein the hydro-energy device is connected with the laser through a pipeline.

Furthermore, a laser head is assembled on the laser, and the laser head is aligned with the metal wire conveyed by the wire feeder on the substrate.

Furthermore, a high-speed camera is arranged on the laser, and a camera of the high-speed camera is aligned with the deposition process of shooting the metal wire.

Preferably, the output end of the controller is further connected with a human-computer interaction module for displaying the information acquired in the acquisition card.

A test method for additive manufacturing based on combination of resistance heating wire materials and laser comprises the following steps:

polishing and flatly placing the substrate on a heating device, and starting a heating power supply through a controller to preheat;

moving the fixed connecting rod through the movable machine tool to enable the wire feeder to move to the substrate, conveying the metal wire to the substrate through the wire feeder, setting a current and voltage value of the programmable power supply when the distance between the metal wire and the substrate is 0.5-1 mm, and starting the laser deposition system to be in a preparation state;

the controller starts a printing process, the wire feeder and the laser deposition system move synchronously, and a first layer of additive sample is deposited on the substrate;

and modifying a track movement program on a controller or manually re-determining an initial point of the platform, starting the printing process again, enabling the wire feeder and the laser deposition system to move synchronously, depositing on the substrate to form a second layer of additive test sample, and sequentially circulating until a formed part is printed, wherein the additive manufacturing test is finished.

Preferably, the output power P of the laser deposition system is 400W-600W; the scanning speed V of the laser deposition system is 350 mm/min-500 mm/min.

Preferably, the one-side descending height of the movable machine tool is 0.2 mm-0.6 mm.

Compared with the prior art, the invention has the following beneficial technical effects:

the invention provides an additive manufacturing device based on compounding of resistance heating wire materials and laser, which is used for additive manufacturing by taking resistance heating and laser as heat sources and adopting a resistance heating and laser compounding additive method.

Furthermore, the argon device can protect the heated metal wire material in a molten pool formed by irradiation of a laser, and deposition is facilitated.

Furthermore, the laser deposition system comprises a laser and a water energy device, wherein the water energy device is connected with the laser through a pipeline and used for water cooling when the laser is heated, and the laser is prevented from being damaged by high temperature.

Furthermore, a laser head is assembled on the laser, and the laser head is aligned with the metal wire conveyed by the wire feeder on the substrate, so that the metal wire can be irradiated and heated to form a molten pool.

Furthermore, a high-speed camera is arranged on the laser, and a camera of the high-speed camera is aligned to the deposition process of the shot metal wire, so that the deposition process of the metal wire can be shot conveniently in real time.

A test method for additive manufacturing based on resistance heating wire material and laser compounding is characterized in that a pulse wire feeding mechanism and a programmable heating power supply are adopted to short circuit a metal wire material and a substrate, the wire material is melted by resistance heating, and the pulse behavior and the output current of the wire material in the feeding process are matched in a coordinated mode, so that the quantitative melting of the end part of the wire material is realized, and the additive manufacturing of parts is realized in the laser auxiliary heating process. The image change and the change monitoring of the electric signal of the wire heating process are realized by utilizing a high-speed camera system CCD and a voltage and current acquisition system. The invention takes resistance heating as a main heat source and laser as an auxiliary heat source, establishes an electric-laser composite fuse wire additive manufacturing model based on minimum energy constraint and proves the feasibility of the process. Aiming at the problems of difficult control of forming quality and the like, the forming mechanism and the forming process need to be deeply researched. Therefore, the project researches the interaction of the composite heat source, the heat and mass transfer mechanism, the deposition and molding quantity-effect relationship in the additive manufacturing of the electro-laser composite fuse wire, the influence rule of process parameters and the like, and has important research value for improving the precision and the quality of parts.

Drawings

FIG. 1 is a schematic structural diagram of an additive manufacturing device based on compounding of resistance heating wire material and laser.

In the figure: 1-a substrate; 2-a heating device; 3-a programmable power supply; 4-a wire feeder; 5-metal wire; 6-moving the machine tool; 7-a laser; 8-a current sensor; 9-a voltage sensor; 10-acquisition card; 11-a controller; 12-a high-speed camera; 13-a laser head; 14-a heating power supply; 15-a water cooling device; 16-fixed connecting rod, 17-argon device; 18-additive test sample; 19-molten pool.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

The invention is described in further detail below with reference to the accompanying drawings:

referring to fig. 1, in one embodiment of the present invention, a material increase manufacturing device based on resistance heating wire material and laser compounding is provided, the device has a simple structure, low equipment cost, high energy conversion efficiency, high forming efficiency and small deformation of formed parts, and can solve the neck clamping problems of large stress, large deformation, easy cracking and the like of existing parts.

Specifically, the device comprises a laser deposition system, an electric heating system, a wire feeder 4, a substrate 1, a mobile machine tool 6 and a controller 11, wherein the controller 11 is respectively connected with a power supply of the laser deposition system, the electric heating system and the wire feeder 4; the laser deposition system and the wire feeder 4 are respectively connected to the mobile machine tool 6 through a fixed connecting rod 16;

the electric heating system comprises a heating device 2, a programmable power supply 3, a current sensor 8, a voltage sensor 9, a collecting card 10 and a heating power supply 14; the heating device 2 is assembled at the bottom end of the substrate 1, one electrode of the programmable power supply 3 is connected to the substrate 1, the other electrode of the programmable power supply is connected to the wire feeder 4, a metal wire 5 is filled in the wire feeder 4, and when the metal wire 5 contacts the substrate 1 through the wire feeder 4, a loop is formed after the programmable power supply 3 is electrified; the acquisition card 10 is connected to a circuit of the programmable power supply 3 through a current sensor 8 and a voltage sensor 9, and the heating power supply 14 is connected to the heating device 2;

the laser deposition system and the wire feeder 4 synchronously move on the substrate 1 through the mobile machine tool 6, laser output by the laser deposition system is arranged towards the metal wire 5, and the metal wire 5 is printed on the substrate 1 through heating of the heating device 2 to form an additive sample 18;

the input end of the controller 11 is connected with the signal input module, and the output end of the controller 11 is respectively connected with the power supply control module and the switch control output module; the signal input module is respectively connected with a current sensor 8 and a voltage sensor 9 through a collection card 10; the power supply control module is respectively connected with the programmable power supply 3 and the heating power supply 14; the switch control output module is connected with the laser deposition system; the output end of the controller 11 is also connected with a human-computer interaction module for displaying the information acquired in the acquisition card.

Specifically, the argon gas device 17 is connected to the movable machine tool 6 through a fixed connecting rod 16, the argon gas device 17 and the laser deposition system and the wire feeder 4 move synchronously on the substrate 1, and the output end of the argon gas device 17 is aligned with the metal wire 5 on the substrate 1, so that the metal wire 5 is deposited.

Specifically, the laser deposition system comprises a laser 7 and a hydro-energy device 15, which is connected with the laser 7 through a pipeline. Wherein, a laser head 13 is assembled on the laser 7, and the laser head 13 is aligned with the metal wire 5 conveyed on the substrate 1 by the wire feeder 4; the laser 7 is provided with a high-speed camera 12, and a camera of the high-speed camera 12 is aligned with the deposition process of the shot metal wire 5.

The anode and the cathode of a programmable power supply 3 are respectively connected to a conductive wire feeder 4 and a substrate 1, and wires are electrically heated between the programmable power supply and the substrate; the current sensor 8 and the voltage sensor 9 display the real-time current and voltage in the deposition process on the controller 11 through the acquisition card 10, and the high-speed camera 12 simultaneously shoots the deposition process, so that the real-time monitoring is facilitated.

The invention provides a test method for additive manufacturing based on compounding of resistance heating wire materials and laser, and the test method for additive manufacturing based on compounding of the resistance heating wire materials and the laser comprises the following steps:

polishing and flatly placing the substrate 1 on a heating device, starting a heating power supply 14 through a controller 11 to preheat to enable the temperature to reach 400 DEG C

Moving the fixed connecting rod 16 through the movable machine tool 6, so that the wire feeder 4 moves to the substrate 1, the metal wire 5 is conveyed to the substrate 1 through the wire feeder 4, when the distance between the metal wire 5 and the substrate 1 is 0.5 mm-1 mm, the current and voltage value of the programmable power supply is set, and the hydroenergy device 15 is started, so that the laser 7 is in a ready state;

the controller 11 starts a printing process, the wire feeder 3 and the laser deposition system move synchronously, and a first layer of additive sample 18 is deposited on the substrate 1;

and modifying a track motion program on a controller or manually re-determining an initial point of the platform, starting the printing process again, synchronously moving the wire feeder 3 and the laser deposition system, depositing a second layer of additive test sample 18 on the substrate 1, and sequentially circulating until a formed part is printed, wherein the additive manufacturing test is finished.

The additive manufacturing test method adopts a pulse wire feeding mechanism and a programmable heating power supply to short circuit a metal wire and a substrate (the step is carried out when the metal wire is in contact with the substrate at the beginning of printing), utilizes resistance heating to melt the wire, and cooperates with the pulse action and the output current in the wire feeding process (the process is finished under the cooperative work of a wire feeder, a numerical control platform and a laser), so that the quantitative melting of the end part of the wire is realized, and the additive manufacturing of parts is realized in the laser auxiliary heating process. The image change and the change monitoring of the electric signal of the wire heating process are realized by utilizing a high-speed camera system CCD and a voltage and current acquisition system.

The programmable power supply 3 can change the magnitude of voltage and current in real time, the power supply can be automatically interrupted if problems occur in the deposition process, the anode and the cathode of the programmable power supply 3 are respectively connected to the conductive substrate 1 and the wire feeder 4, after the power supply is electrified, the programmable power supply 3, the substrate 1, the metal wire 5, the wire feeder 4 and the programmable power supply 3 form a loop, the local high temperature is generated at the contact point of the substrate 1 and the metal wire 5 by joule heat to heat the end part of the metal wire 5 to the temperature close to the melting point, then the heated metal wire 5 is sent into a molten pool 19 formed by irradiation of a laser 7 by the movement of a mobile machine tool 6, and the molten pool 19 is cooled under the protection of an argon device 17 and then deposited to form a material increase sample 18.

The laser additive manufacturing process has the following parameter ranges: the output power P of the laser 7 is 400W-600; the scanning speed V of the laser head 7 is 350 mm/min-500 mm/min; the single-layer descending height of the movable machine tool 6 is 0.2 mm-0.6 mm; the lap joint rate between adjacent additive sample layers is 35-45%. The high-speed camera 12 and the laser head 13 are offset by 30-60 degrees, wherein the high-speed camera 12 has an infrared temperature detection function. According to the metal wire materials with different properties, different main heat sources can be selected, for example, aluminum is used as the metal wire material, the reflectivity to laser is higher, so that resistance heating is used as the main heat source, and laser is used as an auxiliary heat source.

Compared with metal powder, the metal wire 5 adopted by the invention needs higher temperature for completely melting the metal wire 5, thereby undoubtedly reducing the deposition efficiency in the manufacturing process and increasing the energy consumption. The metal wire 5 is heated before being sent into the molten pool, so that the dependence of wire melting on laser power can be reduced, and the fuse wire is more efficient. The electric-laser composite heat source fuse material additive manufacturing technology utilizes joule effect generated by current flowing through metal wire materials when the wire materials are in contact with a substrate, and converts electric energy into heat energy of the wire materials.

The invention adopts the pulse wire feeding mechanism and the programmable heating power supply to short circuit the metal wire and the substrate, melts the wire by resistance heating, and cooperates with the pulse action and the output current in the wire feeding process to realize the quantitative melting of the end part of the wire and the additive manufacturing of parts in the laser auxiliary heating process. The image change and the change monitoring of the electric signal of the wire heating process are realized by utilizing a high-speed camera system CCD and a voltage and current acquisition system. The invention takes resistance heating as a main heat source and laser as an auxiliary heat source, establishes an electric-laser composite fuse wire additive manufacturing model based on minimum energy constraint and proves the feasibility of the process. Aiming at the problems of difficult control of forming quality and the like, the forming mechanism and the forming process need to be deeply researched. Therefore, the project researches the interaction of the composite heat source, the heat and mass transfer mechanism, the deposition and molding quantity-effect relationship in the additive manufacturing of the electro-laser composite fuse wire, the influence rule of process parameters and the like, and has important research value for improving the precision and the quality of parts.

Compared with the existing mainstream high-energy beam additive manufacturing technology, the additive manufacturing and forming method of the invention comprises the following steps: the forming method has the advantages that the equipment cost is low, the energy conversion efficiency is high, the forming efficiency is high, the deformation of formed parts is small, the problem that many parts have necks with large stress, large deformation, easy cracking and the like at present can be solved, some simple parts are formed and some performance tests are carried out, the forming energy consumption is half of that of pure laser/electron beam additive manufacturing, the forming efficiency is improved by nearly 4 times compared with that of the pure laser additive manufacturing, the stress deformation of the parts is nearly zero, and the defect volume ratio of the parts is nearly zero. Has great research value and application prospect.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting the same, and although the present invention is described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications and equivalents may be made to the embodiments of the invention without departing from the spirit and scope of the invention, which is to be covered by the claims.

Claims

1. The additive manufacturing device based on resistance heating wire material and laser compounding is characterized by comprising a laser deposition system, an electric heating system, a wire feeder (4), a substrate (1), a mobile machine tool (6) and a controller (11), wherein the controller (11) is respectively connected with a power supply of the laser deposition system, the electric heating system and the wire feeder (4); the laser deposition system and the wire feeder (4) are respectively connected to a mobile machine tool (6) through a fixed connecting rod (16);

the electric heating system comprises a heating device (2), a programmable power supply (3), a current sensor (8), a voltage sensor (9), a collection card (10) and a heating power supply (14); the heating device (2) is assembled at the bottom end of the substrate (1), one electrode of the programmable power supply (3) is connected to the substrate (1), the other electrode of the programmable power supply is connected to the wire feeder (4), a metal wire (5) is arranged in the wire feeder (4), and when the metal wire (5) contacts the substrate (1) through the wire feeder (4), the programmable power supply (3) is electrified to form a loop; the acquisition card (10) is connected to a circuit of a programmable power supply (3) through a current sensor (8) and a voltage sensor (9), and the heating power supply (14) is connected to the heating device (2);

the laser deposition system and the wire feeder (4) synchronously move on the substrate (1) through the mobile machine tool (6), laser output by the laser deposition system is arranged towards the metal wire (5), and the metal wire (5) is printed on the substrate (1) through heating of the heating device (2) to form an additive sample (18);

the input end of the controller (11) is connected with the signal input module, and the output end of the controller (11) is respectively connected with the power supply control module and the switch control output module; the signal input module is respectively connected with a current sensor (8) and a voltage sensor (9) through an acquisition card (10); the power supply control module is respectively connected with a programmable power supply (3) and a heating power supply (14); and the switch control output module is connected with the laser deposition system.

2. The additive manufacturing device based on resistance heating wire and laser compounding of claim 1, further comprising an argon gas device (17), wherein the argon gas device (17) is connected to the mobile machine tool (6) through a fixed connecting rod (16), the argon gas device (17) moves synchronously with the laser deposition system and the wire feeder (4) on the substrate (1), and the output end of the argon gas device (17) is aligned with the metal wire (5) on the substrate (1) so that the metal wire (5) is deposited.

3. The additive manufacturing device based on the combination of the resistance heating wire material and the laser according to claim 1, wherein the laser deposition system comprises a laser (7) and a water energy device (15), and the water energy device is connected with the laser (7) through a pipeline.

4. An additive manufacturing device based on resistive heating wire and laser compounding according to claim 3, characterized in that the laser (7) is equipped with a laser head (13), the laser head (13) is aligned with the metal wire (5) transported by the wire feeder (4) on the substrate (1).

5. The additive manufacturing device based on resistance heating wire and laser compounding of claim 3, wherein a high-speed camera (12) is arranged on the laser (7), and a camera of the high-speed camera (12) is aligned to shoot a deposition process of the metal wire (5).

6. The additive manufacturing device based on the compounding of resistance heating wire materials and laser light as claimed in claim 1, wherein the output end of the controller (11) is further connected with a human-computer interaction module for displaying the information collected in the collection card.

7. A test method for additive manufacturing based on compounding of resistance heating wire materials and laser, which is based on the additive manufacturing device based on compounding of resistance heating wire materials and laser in any one of claims 1-6, and is characterized by comprising the following steps:

polishing and flatly placing the substrate (1) on a heating device, and starting a heating power supply (14) through a controller (11) to preheat;

moving the fixed connecting rod (16) through the movable machine tool (6), so that the wire feeder (4) is moved to the substrate (1), the metal wire (5) is conveyed to the substrate (1) through the wire feeder (4), when the distance between the metal wire (5) and the substrate (1) is 0.5-1 mm, the current and voltage value of the programmable power supply is set, and the laser deposition system is started to be in a preparation state;

the controller (11) starts a printing process, the wire feeder (3) and the laser deposition system move synchronously, and a first layer of additive sample (18) is deposited and formed on the substrate (1);

and modifying a track motion program on a controller or manually re-determining an initial point of the platform, starting the printing process again, synchronously moving the wire feeder (3) and the laser deposition system, depositing and forming a second layer of additive test samples (18) on the substrate (1), and sequentially circulating until a formed part is printed, wherein the additive manufacturing test is finished.

8. The experimental method for additive manufacturing based on combination of resistance heating wire material and laser according to claim 7, wherein the output power P of the laser deposition system is 400W-600W; the scanning speed V of the laser deposition system is 350 mm/min-500 mm/min.

9. The test method for additive manufacturing based on resistance heating wire and laser compounding of claim 7, wherein the one-side descent height of the moving machine tool (6) is 0.2mm to 0.6 mm.