Electric and magnetic field coupling assisted laser-electric arc hybrid welding device and method for welding rare earth aluminum alloy through electric and magnetic field coupling assisted laser-electric arc hybrid welding device

Abstract

The invention discloses an electric and magnetic field coupling auxiliary laser hybrid welding device and a rare earth aluminum alloy welding method thereof.The electric and magnetic field coupling auxiliary laser hybrid welding device comprises an electric field power source, a magnetic field power source, a magnetic field coil, a controller of the magnetic field coil, a laser transmitter, a welding gun, a connecting plate, a bolt and a workpiece to be welded; the laser beam penetrates through the center of the magnetic field coil, the magnetic field coil is fixedly connected with the laser transmitter through the connecting plate, the positive electrode of the electric field power supply is connected with a workpiece to be welded, and the negative electrode is connected with the tail end of the laser transmitter; an electric field and a magnetic field are additionally arranged, the electric field accelerates movement of charged particles, then Lorentz force of the charged particles in the plasma under the action of the magnetic field is increased, the charged particles are promoted to move towards a workpiece, the shielding effect is reduced, and the fusion depth is increased; and meanwhile, the electromagnetic force can stir the molten pool to enhance heat transfer and convection of liquid metal in the molten pool, so that a temperature field and solute in the molten pool are homogenized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of laser welding, in particular to an electric and magnetic field coupling assisted laser-arc hybrid welding device and a welding rare earth aluminum alloy method thereof. BACKGROUND

[0002] Aluminum alloy is the first choice for automobile lightweight, energy saving and emission reduction due to its high specific strength, good thermal conductivity, good corrosion resistance, easy processing and forming, good regeneration and low price. Welding is the most important processing method for automobile aluminum alloy structure manufacturing, among which fusion welding is the most widely used and most important aluminum alloy welding technology. However, aluminum alloy welding is different from steel welding, and there are still many problems.

[0003] Aluminum alloy laser-arc hybrid welding technology has the advantages of large penetration, high efficiency and small deformation of laser welding, and good bridging and strong adaptability of arc welding. However, the conventional Al-Si alloy welding wire used at present is unstable in quality, which easily leads to the hydrogen in the welding wire being left in the weld, resulting in a large number of pores (metallurgical type) in the joint, affecting the weld quality and mechanical properties. The addition of rare earth elements La and Ce in the welding wire can achieve good hydrogen removal effect, but how to make the two kinds of rare earth elements uniformly distributed in the welded joint becomes a big difficulty in laser-arc hybrid welding of aluminum alloy.

[0004] In addition, during laser-arc hybrid welding, the high energy density laser causes the metal vapor to ionize, forming a plasma cloud above the workpiece. This plasma cloud absorbs, scatters and reflects the incident laser energy, significantly reducing the effective utilization of the laser, resulting in shallow welding penetration and unstable process. This phenomenon is particularly serious in high-power laser welding.

[0005] Therefore, the present application provides an electric and magnetic field coupling assisted laser-arc hybrid welding rare earth aluminum alloy method to solve the above problems. SUMMARY

[0006] The primary object of the present application is to provide an electric and magnetic field coupling assisted laser-arc hybrid welding device, which solves the problems of uneven distribution of rare earth elements and weakening of plasma in the process of laser-arc hybrid welding of rare earth aluminum alloy, and has the characteristics of reasonable structure and easy operation.

[0007] Another object of the present application is to provide a related welding rare earth aluminum alloy method, which has the characteristics of scientific and reasonable process and easy operation, and effectively improves the internal quality of the weld and the mechanical properties of the welded joint.

[0008] The technical scheme for solving the primary technical problem of the present application is: an electric and magnetic field coupling assisted laser-arc hybrid welding device, comprising:

[0009] a laser emitter arranged in front of the welding direction for emitting a laser beam for welding;

[0010] a magnetic field coil arranged below the laser emitter for allowing the laser beam to pass through the center of the magnetic field coil;

[0011] a magnetic field controller connected to the output of the magnetic field coil for providing alternating current to the magnetic field coil;

[0012] a magnetic field power supply connected to the input of the magnetic field controller for providing power to the magnetic field controller;

[0013] an electric field power supply with its positive pole connected to the workpiece to be welded and its negative pole connected to the end of the laser emitter;

[0014] a welding torch arranged behind the welding direction.

[0015] Further, the magnetic field coil is fixedly connected to the laser emitter through two side connecting plates and bolts.

[0016] Further, the upper part of the connecting plate is designed as two sliding holes and the lower part is designed as a through hole, and the magnetic field coil and the laser emitter are connected through the connecting plate, and the height of the magnetic field coil is adjusted by adjusting the position of the sliding hole.

[0017] Further, the magnetic field coil and the laser emitter are coaxially arranged; and the laser emitter is fixedly connected to the welding torch through a clamp.

[0018] Further, the welding wire used for welding is a rare earth aluminum alloy welding wire, and La and Ce two rare earth elements are added to the welding wire.

[0019] Further, the material of the workpiece to be welded used for welding is 6061 aluminum alloy, and the thickness is 10±1mm.

[0020] Further, the welding method is butt joint, the groove form is Y-type groove, and the assembly gap of the workpiece to be welded is 0-1mm.

[0021] Finally, the electric field power supply provides voltage by using a voltage continuously adjustable (0-220V) DC power supply.

[0022] The technical solution of the present application solves another technical problem, which is a method for electric and magnetic field coupling assisted laser-arc hybrid welding of rare earth aluminum alloy, characterized in that any one of the electric and magnetic field coupling assisted laser-arc hybrid welding devices described above is used, and the method comprises the following steps:

[0023] S1, the to-be-welded workpiece and the rare earth aluminum alloy welding wire are placed in an oven for drying for 2-4 hours, the temperature is set to 80±5 DEG C, after taking out, the butt joint position of the welding seam is mechanically polished, and the butt joint surface is wiped clean with alcohol;

[0024] S2, the to-be-welded workpiece is fixed, and the front end and the rear end position are spot welded by a welding gun;

[0025] S3, set the laser working parameters, the laser power is 2-5kW, the laser galvanometer swing amplitude is 1-1.2mm, and the swing frequency is 200-300Hz;

[0026] S4, set the arc working parameters, the current is 180-220A, and the welding speed is 0.6-1m / min;

[0027] S5, set the electric field parameters, the electric field power supply provides voltage by using a continuously adjustable (0-220V) DC power supply;

[0028] S6, set the magnetic field working parameters, the magnetic field strength is 60-90mT;

[0029] S7, set the running track of the welding mechanical arm, the mechanical arm swing amplitude is 0-9mm;

[0030] S8, turn on the electric field power supply, start the magnetic field power supply and its magnetic field controller, the laser and the arc start to emit light and arc according to the mechanical arm program, and the mechanical arm welds according to the preset track;

[0031] S9, after welding, the electric field power supply, the magnetic field power supply and its magnetic field controller are turned off.

[0032] Finally, the welding environment humidity is controlled below 40%.

[0033] Compared with the prior art, the present application has the following beneficial technical effects:

[0034] 1. Rare earth elements La and Ce are added in conventional Al-Si alloy welding wire, the purification, refinement, modification, solid solution and beneficial second phase generation effects of rare earth elements are utilized, so that the welding wire hydrogen content is reduced, the organization is refined, and the joint mechanical property is improved.

[0035] 2. The electromagnetic force can produce stirring effect on the molten pool, which can strengthen the heat transfer and convection of the liquid metal in the molten pool, and homogenize the solute including rare earth elements La, Ce and the like in the molten pool.

[0036] 3. The external electric field and magnetic field accelerate the movement of charged particles, and then increase the Lorentz force of charged particles in the plasma under the action of the magnetic field, so as to make the charged particles move to the workpiece direction, reduce the shielding effect, and increase the penetration depth.

[0037] The process is scientific and reasonable, and convenient to operate, which not only effectively inhibits the shielding effect of laser-induced plasma on laser, improves the energy transmission of laser, increases the penetration depth, but also improves the internal quality of the weld and the mechanical properties of the welded joint, which is particularly important for industries with strict requirements on welding efficiency, such as automobile manufacturing, aerospace and electronic equipment manufacturing. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 It is a schematic diagram of the working principle structure of the application;

[0039] Figure 2 It is a schematic diagram of the connecting plate structure of the application;

[0040] Figure 3 It is a schematic diagram of the structure of the workpiece to be welded of the application;

[0041] Figure 4 It is a comparison diagram of pores; it is a comparison between welding without power supply and magnetic field coupling and welding with power supply and magnetic field coupling. DETAILED DESCRIPTION

[0042] The technical solutions of the application will be described in detail below in combination with the drawings and specific embodiments. The technical solutions in the embodiments of the application are described clearly and completely, obviously, the described embodiments are part of the embodiments of the application, not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor should belong to the protection scope of the application.

[0043] All other embodiments obtained by those skilled in the art without creative labor should belong to the protection scope of the application.

[0044] In this application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrated; it can be mechanical connection, or electrical connection, or communication; it can be directly connected, or indirectly connected through intermediate medium, or the communication or interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0045] The embodiments of the application will be described in detail below, and the examples of the embodiments are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary, only for explaining the application, and cannot be understood as limiting the application

[0046] Reference Figures 1 to 3The application discloses an electric and magnetic field coupling assisted laser-arc hybrid welding device which can be used for welding rare earth aluminum alloy.

[0047] With reference to Figure 1 The application comprises main components such as an electric field power supply 5, a magnetic field power supply 3, a magnetic field coil 2, a magnetic field controller 4, a laser emitter 1, a welding torch 6, a connecting plate 7, a bolt 8 and a workpiece 9 to be welded.

[0048] The welding mode is a laser-in-front-arc-behind welding mode, that is, the laser emitter 1 serving as a laser welding head is arranged in front of the welding direction, and the arc welding torch 6 is arranged behind the welding direction, and the laser welding head and the arc welding torch are fixedly connected through a clamp.

[0049] The magnetic field device is composed of the magnetic field coil 2, the magnetic field power supply 3 and the magnetic field controller 4, the magnetic field power supply 3 is connected to the magnetic field coil 2 through the magnetic field controller 4, the magnetic field controller 4 generates alternating current to periodically change the magnetic field direction generated by the current, and the maximum magnetic induction intensity is 280 mT. The laser beam passes through the center of the magnetic field coil 2, the magnetic field coil 2 is fixedly connected with the laser emitter 1 through the connecting plate 7 by the bolt 8, and is coaxially arranged.

[0050] With reference to Figure 2 The upper part of the connecting plate 7 is designed as two sliding holes 71 and 72, and the lower part is designed as a through hole 73, the magnetic field device and the laser welding head are connected together through the connecting plate 7, and the height of the magnetic field coil 2 is adjusted by adjusting the positions of the sliding holes 71 and 72.

[0051] The electric field device adopts the electric field power supply 5 which is provided with a voltage continuous adjustable (0-220V) direct current power supply, the positive pole of the electric field power supply 5 is connected with the workpiece 9 to be welded, and the negative pole is connected with the tail end of the laser emitter 1.

[0052] With reference to Figure 3 The workpiece 9 to be welded is a 6061 aluminum alloy test plate, the welding mode is butt joint, the size of the test plate is 300*150*10mm, the blunt edge of 4-5mm is reserved on the butt joint side, the groove is Y-shaped, the groove angle is 65-70°, and the gap between the butt joint welds is 0-1mm.

[0053] Before welding the workpiece by using the electric and magnetic field coupling assisted laser-arc hybrid welding method for rare earth aluminum alloy in the application, the workpiece to be welded and the rare earth aluminum alloy welding wire are placed in an oven and dried for 2-4 hours, the temperature is set to 80 DEG C, after taking out, the butt joint position of the weld is mechanically polished, the butt joint surface is cleaned with alcohol, and then the workpiece is placed in a welding station and fixed by a pressing device.

[0054] Spot weld the first and last ends of the workpiece to be welded with an arc welding gun. Set the spot welding current to 140-160A. After spot welding, use an angle grinder to re-grind the first and last ends into the above-mentioned bevel shape. Then, mechanically grind the first and last ends and wipe them with alcohol.

[0055] Reference Figure 3 The dimensions and bevel type of the workpiece to be welded are determined by a single-pass, multi-layer welding method, including a root pass, an intermediate pass, and a cover pass.

[0056] After the above-mentioned preliminary welding work is completed, the present invention will be further described in conjunction with the accompanying drawings and embodiments.

[0057] Example 1

[0058] A method for electro-magnetic field coupled assisted laser-arc hybrid welding of rare earth aluminum alloys, including the method and steps for the root pass welding:

[0059] Step 1: Set the laser operating parameters: laser power of 4-5kW, laser galvanometer swing amplitude of 1-1.2mm, and swing frequency of 200-300Hz.

[0060] Step 2: Set the arc working parameters: current 180–190A, welding speed 0.8–1m / min.

[0061] Step 3: Set the electric field parameters to 100-200V.

[0062] Step 4: Set the magnetic field operating parameters, with the magnetic field strength set to 60–90 mT.

[0063] Step 5: Set the trajectory of the welding robot arm, with the swing amplitude of the robot arm ranging from 0 to 9 mm.

[0064] Step 6: Turn on the electric field power supply, start the magnetic field power supply and its magnetic field controller. The laser and electric arc start to emit light and arc according to the robot arm program. The robot arm performs welding according to the preset trajectory.

[0065] Step 7: Welding complete. Turn off the electric field power supply, magnetic field power supply, and their magnetic field controller.

[0066] Example 2

[0067] A method for electro-magnetic field coupled assisted laser-arc hybrid welding of rare earth aluminum alloys, including the intermediate layer welding method and steps:

[0068] Step 1: Set the laser operating parameters: laser power of 2-2.5kW, laser galvanometer swing amplitude of 1-1.2mm, and swing frequency of 200-300Hz.

[0069] Step 2: Set the arc working parameters: current of 200-220A and welding speed of 0.8-1m / min.

[0070] Step 3, set the electric field parameters, 100-200V.

[0071] Step 4, set the magnetic field working parameters, the magnetic field strength is 60-90mT.

[0072] Step 5, set the welding mechanical arm running track, the robot swing amplitude is 4-6mm.

[0073] Step 6, open the electric field power supply, start the magnetic field power supply and its magnetic field controller, the laser and electric arc start to emit light and arc according to the mechanical arm program, and the mechanical arm welds according to the preset track.

[0074] Step 7, after welding, turn off the electric field power supply, the magnetic field power supply and its magnetic field controller.

[0075] Example 3

[0076] A method of laser-arc hybrid welding of rare earth aluminum alloy assisted by electric and magnetic field coupling, a cover layer welding method and steps:

[0077] Step 1, set the laser working parameters, the laser power is 2-2.5kW, the laser galvanometer swing amplitude is 1-1.2mm, and the swing frequency is 200-300Hz.

[0078] Step 2, set the arc working parameters, the current is 200-220A, and the welding speed is 0.6-0.7m / min.

[0079] Step 3, set the electric field parameters, 100-200V.

[0080] Step 4, set the magnetic field working parameters, the magnetic field strength is 60-90mT.

[0081] Step 5, set the welding mechanical arm running track, the robot swing amplitude is 7-9mm.

[0082] Step 6, open the electric field power supply, start the magnetic field power supply and its magnetic field controller, the laser and electric arc start to emit light and arc according to the mechanical arm program, and the mechanical arm welds according to the preset track.

[0083] Step 7, after welding, turn off the electric field power supply, the magnetic field power supply and its magnetic field controller.

[0084] The comparison results of welding without electric and magnetic field coupling and welding with electric and magnetic field coupling can be seen in Figure 4 The welding with electric and magnetic field coupling of the present application basically has no pores in the weld, so that the welding mechanical properties can be improved.

[0085] The comparison of average grain size of the weld before and after adding rare earth can be seen in Table 1 below;

[0086] Table 1

[0087]

[0088] It can be seen that the average grain size of the weld can be greatly reduced before and after the rare earth is added.

[0089] The mechanical properties of the welding joint before and after the rare earth is added are compared, and Table 2 is referred to.

[0090] Table 2

[0091]

[0092] It can be seen that the welding mechanical properties are significantly improved by adding the rare earth elements La and Ce in the application.

[0093] By using the method for laser-arc hybrid welding of rare earth aluminum alloy assisted by electric and magnetic field coupling in the application to weld the workpiece to be welded, the shielding effect of laser-induced plasma on the laser is suppressed, the energy transmission of the laser is improved, and the penetration depth is increased. At the same time, the electromagnetic force produces stirring effect on the molten pool, which will strengthen the heat transfer and convection of the liquid metal in the molten pool, homogenize the solute including the rare earth elements La and Ce in the molten pool, reduce the generation of welding pores, improve the internal quality of the weld, and improve the mechanical properties of the welding joint. It is particularly important for the industry with strict requirements on welding efficiency, such as automobile manufacturing, aerospace and electronic equipment manufacturing fields.

[0094] In the description of the present specification, the description of the terms "one embodiment", "example", "specific example" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0095] The preferred embodiments of the application disclosed above are only used to help explain the application. The preferred embodiments do not describe all the details and limit the application to the specific embodiments described. Obviously, many modifications and changes can be made according to the content of the present specification. The present specification selects and describes these embodiments in order to better explain the principles and practical applications of the application, so that those skilled in the art can well understand and utilize the application. The application is limited by the claims and their entire scope and equivalents.

Claims

1. An electric and magnetic field coupling assisted laser-arc hybrid welding device, comprising: a laser emitter arranged in front of the welding direction for emitting a laser beam for welding; a magnetic field coil arranged below the laser emitter, allowing the laser beam to pass through the center of the magnetic field coil; a magnetic field controller connected to the magnetic field coil to provide alternating current for the magnetic field coil; a magnetic field power supply connected to the input of the magnetic field controller to provide power; an electric field power supply, the positive electrode of which is connected to the workpiece to be welded, and the negative electrode of which is connected to the end of the laser emitter; a welding torch arranged behind the welding direction.

2. The composite welding device of claim 1, wherein The magnetic field coil is fixedly connected with the laser emitter by two side connecting plates and bolts.

3. The composite welding device of claim 2, wherein The upper part of the connecting plate is designed as two sliding holes, and the lower part is designed as a through hole, which connects the magnetic field coil and the laser emitter through the connecting plate, and adjusts the height of the magnetic field coil by adjusting the position of the sliding hole.

4. The composite welding device of claim 3, wherein The magnetic field coil and the laser emitter are coaxially arranged; the laser emitter is fixedly connected with the welding torch through a clamp as a laser welding head.

5. The composite welding device of claim 1, wherein The welding wire used for welding is a rare earth aluminum alloy welding wire, and La and Ce two rare earth elements are added to the welding wire.

6. The composite welding device of claim 1, wherein The material of the workpiece to be welded is 6061 aluminum alloy with a thickness of 10±1 mm.

7. The composite welding device of claim 1, wherein The welding method is butt joint, and the groove form is Y-type groove, and the assembly gap of the workpiece to be welded is 0-1 mm.

8. The composite welding device of claim 1, wherein The electric field power supply provides voltage by using a continuously adjustable (0-220V) DC power supply.

9. A method of electric, magnetic field coupled assisted laser-arc hybrid welding of rare earth aluminum alloys, characterized in that The electric and magnetic field coupling assisted laser-arc hybrid welding device of any one of claims 1-8 comprises the following steps: S1, dry the workpiece to be welded and the rare earth aluminum alloy welding wire in an oven for 2-4 hours, set the temperature to 80±5℃, take out and mechanically polish the butt joint position of the weld, and wipe the butt joint surface clean with alcohol; S2, fix the workpiece to be welded, and point weld the front and rear positions with the welding torch; S3, set the laser working parameters, the laser power is 2-5kW, the laser galvanometer swing amplitude is 1-1.2mm, and the swing frequency is 200-300Hz; S4, set the arc working parameters, the current is 180-220A, and the welding speed is 0.6-1m / min; S5, set the electric field parameters, the electric field power supply provides voltage by using a continuously adjustable (0-220V) DC power supply; S6, set the magnetic field working parameters, the magnetic field strength is 60-90mT; S7, set the running track of the welding mechanical arm, and the mechanical arm swing amplitude is 0-9mm; S8, turn on the electric field power supply, start the magnetic field power supply and its magnetic field controller, and the laser and arc start to emit light and arc according to the mechanical arm program; S9, after welding, turn off the electric field power supply, the magnetic field power supply and its magnetic field controller.

10. The method of claim 9, wherein The welding environment humidity is controlled below 40%.

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