Non-contact laser ultrasonic composite welding device and welding method

Abstract

The invention provides a non-contact laser ultrasonic composite welding device and method, and the device comprises a laser assembly which comprises a first laser generator, a second laser generator and a laser composite emergent head, and the first laser generator and the second laser generator are connected with the laser composite emergent head; the ultrasonic assembly comprises an ultrasonic generator and an ultrasonic welding head; the mounting assembly comprises a mounting clamp, and the laser composite emergent head is arranged on the mounting clamp; the ultrasonic welding head is arranged on the mounting fixture in a swinging manner so as to adjust the inclination angle of the ultrasonic welding head; after the ultrasonic assembly emits ultrasonic waves, the laser assembly outputs laser beams to weld the to-be-machined workpiece. Under the combined action of the ultrasonic assembly and the laser assembly, the effects of reducing intermetallic compound layers, increasing weld penetration, reducing cracks and air holes and refining weld grains are achieved in the stitch welding process of dissimilar metal materials such as copper and aluminum, the welding efficiency is high, and the welding capacity is good.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of laser processing, in particular to a non-contact laser-ultrasonic composite welding device and welding method. BACKGROUND

[0002] In the new energy, 3C and aerospace industries, more and more welding requirements of dissimilar materials have appeared, but most of the welding between different metals has many defects such as low welding strength, poor appearance, and substandard sealing performance. Especially for commonly used dissimilar metals such as copper-aluminum, aluminum-steel, and copper-steel, the main reasons for defects caused by welding of these dissimilar metals are: large difference in melting point, large difference in thermal conductivity, easy formation of brittle intermetallic compounds at the bonding surface, and many process problems in industrial processing. Some cannot be directly welded. The commonly used processing methods in the industrial field are traditional processing methods such as friction stir welding and resistance welding, and the existing dissimilar metal material welding device has the following defects: 1. The bonding quality of the welded dissimilar metal materials is poor, the penetration is insufficient, and many cracks and pores appear. 2. Low welding efficiency and poor welding capacity. SUMMARY

[0003] In view of the deficiencies of the prior art, the purpose of the present application is to provide a non-contact laser-ultrasonic composite welding device and welding method, which has the effects of reducing the intermetallic compound layer, increasing the weld penetration, reducing the cracks and pores, and refining the weld grain during the welding of dissimilar metal materials such as copper-aluminum, and has high welding efficiency and good welding capacity.

[0004] The embodiments of the present application are implemented by the following technical solutions: A non-contact laser-ultrasonic composite welding device, comprising: A laser assembly comprising a first laser generator, a second laser generator, and a laser composite exit head, wherein the first laser generator and the second laser generator are respectively connected to the laser composite exit head; An ultrasonic assembly comprising an ultrasonic generator and an ultrasonic welding head, wherein the ultrasonic generator is connected to the ultrasonic welding head through a signal line; A mounting assembly comprising a mounting clamp, wherein the laser composite exit head is detachably arranged on the mounting clamp to facilitate adjustment of the height position of the laser composite exit head; the ultrasonic welding head is located on one side of the laser composite exit head, and the ultrasonic welding head is swingably arranged on the mounting clamp to adjust the inclination angle of the ultrasonic welding head; A workpiece, wherein the laser assembly outputs a laser beam to weld the workpiece after the ultrasonic assembly emits ultrasonic waves.

[0005] According to a preferred embodiment, the workpiece to be processed comprises at least two metal materials.

[0006] According to a preferred embodiment, the workpiece to be processed is a copper-aluminum metal piece.

[0007] According to a preferred embodiment, the ultrasonic welding head is adjustably connected to the mounting clamp through a connecting assembly, the connecting assembly comprises a swing connecting piece with a circular arc groove and a fixing piece, the circular arc groove of the swing connecting piece is detachably mounted on the mounting clamp through the fixing piece, the swing connecting piece is provided with a sliding groove along the length direction, and the ultrasonic welding head is detachably arranged in the sliding groove through a sliding block mounting piece. Further comprising a blowing mechanism, the air outlet end of the blowing mechanism is directed towards the processing surface of the workpiece to be processed.

[0008] According to a preferred embodiment, the first laser is a blue laser, and the second laser is a single-mode fiber laser.

[0009] According to a preferred embodiment, the angle adjustment range of the ultrasonic welding head is 0-75°, and the vertical height range of the ultrasonic welding head is 0.2mm-1mm.

[0010] According to a preferred embodiment, the power range of the first laser is 200-1500W, and the power range of the second laser is 200-2000W.

[0011] A non-contact laser-ultrasonic composite welding method, comprising the following steps: Step S10, adjusting the welding power of the blue laser and the welding power of the single-mode fiber laser according to the different thicknesses of the copper-aluminum two materials, and adjusting the welding speed of the laser assembly according to the different thicknesses of the copper-aluminum two materials; Step S20, adjusting the ultrasonic wave amplitude and the ultrasonic wave sound emission time of the ultrasonic generator, the ultrasonic wave amplitude is preferably adjusted in the range of 0%-100%, and the ultrasonic wave sound emission time is preferably adjusted in the range of 1-2s, after the parameter adjustment is completed, the parameters are confirmed to be correct; Step S30, confirming that the first laser generator and the second laser generator can normally emit light, and the ultrasonic generator can normally emit ultrasonic waves, then the overall adjustment is completed; Step S40, controlling the ultrasonic generator switch, emitting ultrasonic waves and vibration, and then controlling the laser assembly to emit laser beams for processing, realizing laser-ultrasonic composite welding.

[0012] According to a preferred embodiment, in step S20, the height adjustment and angle adjustment of the ultrasonic welding head are further included. In step S30, the height adjustment of the laser composite exit head is further included.

[0013] According to a preferred embodiment, in step S40, the laser beams emitted by the first laser generator and the second laser generator enter the laser composite exit head through the internal light path conduction system, and the laser composite exit head is controlled to swing at different speeds to lap weld the workpiece to be processed.

[0014] The technical scheme of the embodiment of the present application has at least the following advantages and beneficial effects: The present application sets up an ultrasonic assembly and a laser assembly to work together, which can reduce the intermetallic compound layer, increase the weld penetration, reduce cracks and pores, and refine the weld grain during the lap welding of copper-aluminum and other dissimilar metal materials, has high welding efficiency and good welding capacity, and solves the technical defects such as many weld pores and cracks in the prior art. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical scheme of the embodiment of the present application, the following will briefly introduce the drawings needed to be used in the embodiment, and it should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope, and for those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0016] Figure 1 A structural schematic diagram of a non-contact laser-ultrasonic composite welding device provided by the embodiment of the present application is shown in the figure. Figure 2 A structural schematic diagram of a laser composite exit head and an ultrasonic welding head provided by the embodiment of the present application is shown in the figure. Figure 3 A structural schematic diagram of an ultrasonic welding head and a weld provided by the embodiment of the present application is shown in the figure. Figure 4 A rear view of a mounting clamp provided by the embodiment of the present application is shown in the figure.

[0017] Figure legend: 1, first laser generator; 2, second laser generator; 3, laser composite exit head; 4, ultrasonic generator; 5, ultrasonic welding head; 6, mounting clamp; 7, workpiece to be processed; 8, workbench surface; 9, air blowing mechanism; 10, swing connecting piece; 101, circular arc groove; 102, sliding groove; 103, sliding block mounting piece. DETAILED DESCRIPTION

[0018] In order to better understand and implement, the technical scheme in the embodiment of the present application will be described clearly and completely in combination with the drawings in the embodiment of the present application.

[0019] In the description of the present application, it should be noted that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terminology used in the specification of the present application herein is only for the purpose of describing specific embodiments and is not intended to limit the present application. Embodiments

[0021] Please refer to Figures 1 to 4 Please refer to Figures 1 to 4 A non-contact laser-ultrasonic composite welding device, comprising: a laser assembly comprising a first laser generator 1, a second laser generator 2, and a laser composite exit head 3, the first laser generator 1 and the second laser generator 2 being connected to the laser composite exit head 3 respectively; an ultrasonic assembly comprising an ultrasonic generator 4 and an ultrasonic welding head 5, the ultrasonic generator 4 being connected to the ultrasonic welding head 5 through a signal line; a mounting assembly comprising a mounting clamp 6, the laser composite exit head 3 being detachably arranged on the mounting clamp 6 to facilitate adjustment of the height position of the laser composite exit head 3; the ultrasonic welding head 5 being located on one side of the laser composite exit head 3 and being swingably arranged on the mounting clamp 6 to adjust the inclination angle of the ultrasonic welding head 5; and a workpiece 7 to be processed, the laser assembly outputting a laser beam to weld the workpiece 7 to be processed after the ultrasonic assembly emits ultrasonic waves.

[0022] Preferably, the workpiece 7 to be processed comprises at least two metal materials.

[0023] Preferably, the workpiece 7 to be processed is a copper-aluminum metal piece.

[0024] Preferably, the ultrasonic welding head 5 is adjustably connected with the mounting clamp 6 through a connecting assembly, the connecting assembly comprising a swing connecting piece 10 provided with a circular arc groove 101, a fixing piece, the circular arc groove 101 of the swing connecting piece 10 being detachably mounted on the mounting clamp 6 through the fixing piece, the swing connecting piece 10 being provided with a sliding groove 102 along the length direction, and the ultrasonic welding head 5 being detachably arranged in the sliding groove 102 through a sliding block mounting piece 103; the position of the sliding block mounting piece 103 in the sliding groove 102 can be adjusted by loosening the locking piece, so as to adjust the distance between the ultrasonic welding head 5 and the workpiece 7 to be processed. The position of the circular arc groove 101 relative to the mounting clamp 6 can be adjusted by loosening the locking piece, so as to adjust the inclination angle between the ultrasonic welding head 5 and the workpiece 7 to be processed. In addition, the swing connecting piece 10 can also be connected with the mounting clamp 6 through horizontal sliding movement, so as to adjust the horizontal position of the swing connecting piece 10, which can be shown in the accompanying drawings. The fixing piece, the locking piece and the like can be selected as detachable fixing structures such as bolts. Figure 4

[0025] The method further comprises a blowing mechanism 9, and an air outlet of the blowing mechanism 9 faces a processing surface of the workpiece 7 to be processed.

[0026] Preferably, the first laser is a blue laser, and the second laser is a single-mode fiber laser.

[0027] Preferably, the angle adjustment range of the ultrasonic welding head 5 is 0-75°, and the vertical height range of the ultrasonic welding head 5 is 0.2mm-1mm.

[0028] Preferably, the power range of the first laser is 200-1500W, and the power range of the second laser is 200-2000W.

[0029] A non-contact laser-ultrasonic composite welding method, comprising the following steps: Step S10, adjusting the welding power of the blue laser and the welding power of the single-mode fiber laser according to different thicknesses of copper and aluminum materials, and adjusting the welding speed of the laser assembly according to different thicknesses of copper and aluminum materials; Step S20, adjusting the ultrasonic wave amplitude and the ultrasonic wave emitting time of the ultrasonic generator 4, the ultrasonic wave amplitude being preferably adjusted in the range of 0%-100%, and the ultrasonic wave emitting time being preferably adjusted in the range of 1-2s, and after the parameter adjustment is completed, the parameters are confirmed to be correct; Step S30, confirming that the first laser generator 1 and the second laser generator 2 can normally emit light, and the ultrasonic generator 4 can normally emit ultrasonic waves, so that the overall adjustment is completed; Step S40, controlling the ultrasonic generator 4 to emit ultrasonic waves and vibrate, and then controlling the laser assembly to emit a laser beam for processing, so as to realize laser-ultrasonic composite welding.

[0030] ​Preferably, in step S20, height adjustment and angle adjustment of the ultrasonic welding head 5 are further included. In step S30, height adjustment of the laser composite exit head 3 is further included.

[0031] Preferably, in step S40, the laser beams emitted by the first laser generator 1 and the second laser generator 2 enter the laser composite exit head 3 through the internal light path conduction system, and the laser composite exit head 3 is controlled to swing at different speeds to lap weld the workpiece 7 to be processed.

[0032] Working principle of the present application: As shown in Figure 3 , the label 11 is the weld position in the present embodiment, the label 13 is the vertical distance from the ultrasonic welding head 5 to the surface of the workpiece 7 to be processed, which can be selected in the range of 0.1-1mm, and the label 12 is the horizontal distance between the ultrasonic welding head 5 and the weld, which can be selected as 0mm.

[0033] In the present embodiment in the aspect of copper-aluminum dissimilar welding, first, the corresponding wavelength of laser is selected according to the material absorption characteristics of copper-aluminum dissimilar lap welding, and according to the characteristics of the pigment absorption spectrum line of copper-aluminum dissimilar welding, the laser of blue light band, infrared band and visible band can be selected, in the present embodiment, the first laser generator 1 selects a 2000W / 300μm blue light laser with a wavelength of 455nm, and the second laser generator 2 selects a 3000W / 20μm single-mode fiber laser with a wavelength of 1064nm.

[0034] The workpiece 7 to be processed in the present embodiment is a copper-aluminum dissimilar metal workpiece 7, before the copper-aluminum dissimilar metal material is lap welded, the fixed position of the ultrasonic welding head 5 and the setting of the ultrasonic generator 4 need to be debugged, the non-contact ultrasonic wave auxiliary device is selected for the ultrasonic assembly, the fixed frequency is 20KHz, the frequency cannot be adjusted, the amplitude can be adjusted, the adjustment range is 0%-100%, the amplitude is adjusted according to the actual demand of the experimental material thickness, the energy is proportional to the amplitude output, the ultrasonic time is determined according to the welding time, the ultrasonic auxiliary time needs to be greater than the actual welding time, the ultrasonic generator 4 controls the ultrasonic welding head 5 by using the signal line, the ultrasonic generator 4 controls the control box to transmit ultrasonic waves by using the external switch, and then controls the ultrasonic welding head 5 to vibrate by using the signal line.

[0035] After the ultrasonic welding head 5 is fixed, the welding direction of the weld 11 and the position of the ultrasonic welding head 5 in the weld 11 need to be considered, when the ultrasonic welding head 5 is located on the side of the weld and the distance is 0mm (the ultrasonic welding head 5 is inclined, the distance between the rightmost vertical line of the ultrasonic welding head 5 and the leftmost vertical line of the weld side), the weld and the ultrasonic welding head 5 are in spatial parallel, and the maximum ultrasonic auxiliary effect is obtained, and the specific ultrasonic welding head 5 bottom and weld 11 position diagram is shown in Figure 3 .

[0036] After the ultrasonic auxiliary partial preparation is completed, the first laser generator 1 and the second laser generator 2 are debugged and set, the first laser generator 1 and the second laser generator 2 emit laser beams through the laser control system, the laser beams enter the blue light composite exit head through the internal light path conduction system, the laser composite exit head 3 can be moved up and down by connecting and adjusting the lifting workbench, so that the focal point position can be determined. In the embodiment, the lifting workbench is not shown, and the lifting workbench, the laser control system, the internal light path conduction system and the like are prior art, which are used to promote the lifting of the laser composite exit head 3. Further, a swing unit can be arranged to drive the laser composite exit head 3 to swing, and the swing unit can select a swing motor and the like driving structure, so it is not necessary to repeat the description. In the embodiment, the laser control system is connected to the first laser generator 1 and the second laser generator 2, and the laser control system is connected to the internal light path conduction system. Figure 1 The workbench surface 8 is provided, and the workbench surface 8 can also be provided with a lifting unit.

[0037] The parameters of the first laser generator 1 and the second laser generator 2 are set by the laser control system, so that a laser beam with a certain energy can form a spiral line on the copper-aluminum overlap welded material according to different speeds of the laser composite exit head 3, the weld direction needs to be located on the side of the welding head, and the distance between the welding head and the side of the weld is zero distance, which is the optimal contact effect. At the same time, the blowing mechanism 9 on one side can remove the dust generated during welding to avoid environmental pollution and is more environmentally friendly. The blowing mechanism 9 can include an air knife.

[0038] After confirming that the first laser generator 1 and the second laser generator 2 can normally emit laser, the laser assembly and the ultrasonic assembly need to be used in cooperation, before starting the copper-aluminum overlap welding, the experimental parameters of the laser assembly and the ultrasonic assembly need to be adjusted, the laser assembly mainly adjusts the welding power of the first laser generator 1 and the welding power of the second laser generator 2, the welding power is adjusted according to the different thicknesses of the copper-aluminum two materials, the welding power of the first laser generator 1 is preferably adjusted in the range of 200-1500W of blue light power, the welding power of the second laser generator 2 is adjusted in the range of 200-2000W, the welding speed is adjusted according to the different thicknesses of the copper-aluminum two materials, and the welding speed of the laser composite welding head is preferably adjusted in the range of 50-100mm / s, the main parameter of the ultrasonic assembly is the ultrasonic amplitude and the ultrasonic sound emission time, the ultrasonic amplitude of the ultrasonic assembly is preferably adjusted in the range of 0%-100%, the ultrasonic sound emission time is preferably adjusted in the range of 1-2s, after the two main part parameters are adjusted, it is confirmed that the parameters are correct and the first laser generator 1 and the second laser generator 2 can normally emit light, and the ultrasonic wave device can normally emit ultrasonic waves, so the overall adjustment is completed.

[0039] The copper-aluminum dissimilar metal material can be welded by selecting the welding mode of aluminum under copper, the welding mode of aluminum on copper, or different thickness combinations of copper and aluminum, and after welding by the combined action of the ultrasonic assembly and the laser assembly, the weld penetration depth improvement ratio is between 30% and 50%, the appearance is more beautiful, the same welding power and welding speed can obtain greater weld penetration depth, the welding efficiency is greatly improved, and the molten pool temperature distribution and component distribution are more uniform. In terms of weld cracks and pores, the traditional welding mode has many pores and cracks, and after the combined action of the laser assembly and the ultrasonic assembly, the pore reduction ratio is between 97% and 99.5%, the porosity and cracks are greatly reduced, when the ultrasonic wave propagates in the molten pool, the pressure at a certain point changes periodically and alternately with time, when the pressure is less than the critical value (cavitation threshold) at a certain moment, the liquid at the point is torn, cavitation bubbles are generated, as the ultrasonic frequency increases, it is more and more difficult to reach the cavitation threshold, which requires increasing the ultrasonic power. Then, due to the periodic change of the pressure, the cavitation bubble will experience vibration, growth and collapse. When the cavitation bubble collapses, due to the extremely fast speed, micro-impact waves and micro-jets are generated, and the energy brought by these effects in the molten pool can break the growing dendrites, and the broken dendrites can provide new nucleation points, which has a positive effect on improving the defects such as coarse dendrites in the copper-aluminum dissimilar metal material welding. Due to the vibration of the base material, intense mechanical vibration will be generated at the solid-liquid interface between the base material and the molten pool, so that the columnar dendrites grown through the interface are broken and the grains are refined, so that the weld quality is improved.

[0040] The technical means disclosed in the present application scheme is not limited to the technical means disclosed in the above-mentioned embodiments, and also includes the technical solutions composed of any combination of the above technical features. It should be pointed out that for ordinary skilled in the art, without departing from the principle of the present application, some improvements and refinements can be made, which are also considered as the protection scope of the present application.

Claims

1. A non-contact laser-ultrasonic hybrid welding apparatus, characterized by, It comprises: laser assembly, including first laser generator, second laser generator, laser composite exit head, the first laser generator, the second laser generator is connected with the laser composite exit head respectively; ultrasonic assembly, including ultrasonic generator and ultrasonic welding head, the ultrasonic generator is connected with the ultrasonic welding head through signal line; mounting assembly, including mounting clamp, the laser composite exit head is detachably arranged on the mounting clamp, so as to adjust the height position of the laser composite exit head;The ultrasonic welding head is located on one side of the laser composite exit head, and the ultrasonic welding head is adjustably arranged on the mounting clamp to adjust the inclination angle of the ultrasonic welding head; The ultrasonic assembly emits ultrasonic waves, and the laser assembly outputs laser beam to weld the workpiece.

2. The non-contact laser ultrasonic composite welding device according to claim 1, wherein the workpiece comprises at least two metal materials.

3. The non-contact laser ultrasonic composite welding device according to claim 1, wherein the workpiece is a copper-aluminum metal piece.

4. The non-contact laser ultrasonic composite welding device according to claim 2, wherein the ultrasonic welding head is adjustably connected with the mounting clamp through a connecting assembly, the connecting assembly comprises a swing connecting piece provided with a circular arc groove and a fixing piece, the circular arc groove of the swing connecting piece is detachably mounted on the mounting clamp through the fixing piece, the swing connecting piece is provided with a sliding groove along the length direction, and the ultrasonic welding head is detachably arranged in the sliding groove through a sliding block mounting piece. It further comprises a blowing mechanism, and the gas outlet end of the blowing mechanism faces the processing surface of the workpiece.

5. The non-contact laser ultrasonic composite welding device according to claim 2, wherein the first laser is a blue laser, and the second laser is a single-mode fiber laser.

6. The non-contact laser ultrasonic composite welding device according to claim 1, wherein the angle adjustment range of the ultrasonic welding head is 0-75°, and the vertical height range of the ultrasonic welding head is 0.2mm-1mm.

7. The non-contact laser ultrasonic composite welding device according to claim 5, wherein the power range of the first laser is 200-1500W, and the power range of the second laser is 200-2000W. The steps comprise: Step S10, according to different thicknesses of copper-aluminum two materials, adjusting the welding power of the blue laser and the welding power of the single-mode fiber laser, and adjusting the welding speed of the laser assembly according to different thicknesses of copper-aluminum two materials; Step S20, adjusting the ultrasonic wave amplitude and ultrasonic wave emission time of the ultrasonic generator, the ultrasonic wave amplitude is preferably adjusted in the range of 0%-100%, the ultrasonic wave emission time is preferably adjusted in the range of 1-2s, and after the parameter adjustment is completed, the parameters are confirmed to be correct; Step S30, confirming that the first laser generator and the second laser generator can normally emit light, and the ultrasonic generator can normally emit ultrasonic waves, then the overall adjustment is completed. ​ ​ 8. A non-contact laser-ultrasonic hybrid welding method using the non-contact laser-ultrasonic hybrid welding apparatus according to any one of claims 1 to 7, characterized by, ​ ​ ​ ​ Step S40, after controlling the ultrasonic generator switch to emit ultrasonic sound and vibration, controlling the laser assembly to emit laser beam processing to realize laser-ultrasonic composite welding.

9. The non-contact laser-ultrasonic composite welding method according to claim 8, characterized in that, In step S20, the height adjustment and angle adjustment of the ultrasonic welding head are further included. In step S30, the height adjustment of the laser composite exit head is further included.

10. The non-contact laser-ultrasonic composite welding method according to claim 8, characterized in that, In step S40, the laser composite exit head is swung at different speeds to lap weld the workpiece to be processed.

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