Aluminum alloy water-cooled plate laser welding device and method

Abstract

The application provides an aluminum alloy water-cooled plate laser welding device and method, and relates to the technical field of laser welding.The aluminum alloy water-cooled plate laser welding device comprises a laser, a water-cooled plate laser head and a welding machine tool, the water-cooled plate laser head comprises a laser galvanometer and a multi-spot beam splitting assembly arranged in sequence along the laser transmission direction; wherein the laser galvanometer is used for realizing spiral swinging of the laser emitted by the laser; the multi-spot beam splitting assembly is used for splitting the laser into light spots; the welding machine tool is connected with the water-cooled plate laser head and is used for driving the water-cooled plate laser head to move; the action of the welding machine tool and the laser galvanometer makes a plurality of light spots on the aluminum alloy water-cooled plate form a welding pattern which simultaneously spirally swings. The aluminum alloy water-cooled plate laser welding device realizes multi-point simultaneous welding on the water-cooled plate plane, is beneficial to the overflow of pores, performs stirring welding through rotating light spots, reduces the stirring frequency, is stable in the process, can effectively inhibit the generation of pores and reduce the porosity of the welding bead.

Description

Technical Field

[0001] This invention relates to the field of laser welding technology, and more specifically, to a laser welding apparatus and method for aluminum alloy water-cooled plates. Background Technology

[0002] Laser welding, as the most effective welding method currently available, has been widely used in the aerospace, rail vehicle, and new energy vehicle manufacturing industries. This technology boasts significant advantages such as high welding speed, low heat input, and minimal deformation, making it particularly suitable for joining aluminum alloy structural components such as automotive chassis, battery packs, and water-cooled plates. However, laser welding of aluminum alloy water-cooled plates still faces numerous technical challenges. While traditional brazing processes offer high yield rates and process stability, they suffer from inherent drawbacks such as high energy consumption and slow production cycles, resulting in high production costs. In contrast, although laser welding offers a clear cost advantage, under high-speed welding conditions, the weld seam of water-cooled plates is prone to generating a large number of pores, severely affecting the product's airtightness. This porosity problem is particularly pronounced when welding speeds exceed 10 m / min. Summary of the Invention

[0003] This invention aims to solve the problem of porosity defects in high-speed laser welding.

[0004] To address the above problems, this invention provides a laser welding device and method for aluminum alloy water-cooled plates.

[0005] In a first aspect, the present invention provides a laser welding apparatus for aluminum alloy water-cooled plates, comprising a laser, a water-cooled plate laser head, and a welding machine tool. The water-cooled plate laser head includes a laser galvanometer and a multi-spot beam splitter assembly arranged sequentially along the laser transmission direction; wherein...

[0006] Laser galvanometers are used to make the laser emitted by a laser oscillate in a spiral motion;

[0007] Multi-spot beam splitting components are used to split laser beams into multiple spots.

[0008] The welding machine tool is connected to the water-cooled plate laser head to drive the movement of the water-cooled plate laser head.

[0009] The welding machine and laser galvanometer work together to create a welding pattern on the aluminum alloy water-cooled plate with multiple laser spots that simultaneously oscillate in a spiral motion.

[0010] Optionally, the laser galvanometer includes a planar two-dimensional galvanometer and a focusing lens. The planar two-dimensional galvanometer includes a laser X-axis reflecting mirror assembly and a laser Z-axis correcting reflecting mirror assembly. The laser X-axis reflecting mirror assembly and the laser Z-axis correcting reflecting mirror assembly are used to rotate according to the position of the aluminum alloy water-cooled plate and the direction of the laser to guide the laser to the focusing lens.

[0011] Optionally, the laser galvanometer also includes a collimation mechanism through which the laser emitted by the laser reaches the planar two-dimensional galvanometer.

[0012] Optionally, the laser X-axis reflector assembly includes a connected laser X-axis reflector and a laser X-axis oscillating motor, the laser X-axis oscillating motor being used to control the rotation of the laser X-axis reflector; the laser Z-axis correction reflector assembly includes a connected laser Z-axis correction reflector and a laser Z-axis correction motor, the laser Z-axis correction motor being used to control the rotation of the laser Z-axis correction reflector.

[0013] Optionally, the laser and the water-cooled plate laser head are connected by optical fiber, with the fiber core diameter being 50 to 100 μm and the fiber cladding diameter being 200 to 400 μm.

[0014] Optionally, the laser emitted by the laser is a ring-shaped spot.

[0015] Optionally, the welding machine tool includes a machine tool controller and a machine tool guide rail connected by a control cable, the machine tool guide rail including a machine tool X guide rail, a machine tool Y guide rail and a machine tool Z guide rail.

[0016] Optionally, the water-cooled plate laser head is mounted on the machine tool guide rail, and the machine tool controller is used to control the machine tool guide rail to move the water-cooled plate laser head.

[0017] Optionally, the laser power is 4500 to 4900W, the welding speed is 5 to 15mm / s, and the laser stirring frequency is 80 to 120Hz.

[0018] Secondly, the present invention provides a laser welding method for aluminum alloy water-cooled plates, based on the aluminum alloy water-cooled plate laser welding apparatus described above, comprising the following steps:

[0019] S1: A laser is emitted by a laser, and a laser galvanometer makes the laser oscillate in a spiral motion;

[0020] S2: The multi-spot beam splitting component splits the laser beam into multiple spots, and through the action of the welding machine tool and the laser galvanometer, it forms a welding pattern on the aluminum alloy water-cooled plate with multiple spots simultaneously spiraling.

[0021] The beneficial effects of the laser welding device and method for aluminum alloy water-cooled plates of the present invention are: the laser achieves spiral oscillation through the laser galvanometer, and the laser galvanometer welding technology is used to fully stir the molten pool, so as to achieve rapid overflow of gas from the keyhole and eliminate porosity. Furthermore, the addition of a multi-spot beam splitting component 22 enables beam splitting. Through the movement of the laser head 2 on the water-cooled plate driven by the welding machine tool and the stirring action of the laser galvanometer, multiple beams can simultaneously form a spiral oscillating pattern on the weld bead of the water-cooled plate. This allows for simultaneous multi-point welding on the water-cooled plate surface, expanding the beam distribution range, increasing the stirring rate of the weld penetration, facilitating gas escape, effectively suppressing porosity, and reducing the porosity of the weld bead to one pore per 2000 square meters, thus improving the airtightness of the water-cooled plate. The multi-spot spiral oscillation mode effectively disperses the heat input energy, avoiding material vaporization caused by localized overheating, while ensuring sufficient penetration of the molten pool, improving the back-side weld formation quality, and contributing to improved welding quality and weld penetration stability. Furthermore, the distance and direction between the multiple beams can be adjusted to suit different weld width requirements, demonstrating high practical production application value. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the laser welding device for aluminum alloy water-cooled plates according to an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the structure of the water-cooled plate laser head according to an embodiment of the present invention;

[0024] Figure 3 This is a flowchart of a laser welding method for aluminum alloy water-cooled plates according to an embodiment of the present invention;

[0025] Figure 4 This is a schematic diagram of the beam pattern after beam splitting in Example 1;

[0026] Figure 5 This is a schematic diagram of the beam spacing after beam splitting in Example 1;

[0027] Figure 6 This is a schematic diagram of the weld width after four-spot beam splitting in Example 1;

[0028] Figure 7 This is a schematic diagram of the welding pattern of multiple light spots simultaneously spiraling on the aluminum alloy water-cooled plate in Example 1;

[0029] Figure 8 This is a schematic cross-sectional view of the molten pool during the laser welding process in Example 1;

[0030] Figure 9 This is a schematic diagram of a welding pattern with a light spot spiraling and oscillating on an aluminum alloy water-cooled plate, as shown in Comparative Example 1.

[0031] Figure 10 This is a schematic diagram of the cross-section of the molten pool during the laser welding process in Comparative Example 1.

[0032] Explanation of reference numerals in the attached figures:

[0033] 1. Laser; 11. Laser; 12. Fiber optic; 2. Water-cooled laser head; 211. Laser X-axis reflector; 212. Laser X-axis oscillating motor; 213. Laser Z-axis correction reflector; 214. Laser Z-axis correction motor; 215. Focusing lens; 216. Collimation mechanism; 22. Multi-spot beam splitting assembly; 31. Control cable; 32. Machine tool controller; 331. Machine tool X-axis guide rail; 332. Machine tool Y-axis guide rail; 333. Machine tool Z-axis guide rail; 4. Aluminum alloy water-cooled plate. Detailed Implementation

[0034] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Although some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the accompanying drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0035] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this invention's description is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0036] As used herein, the term "comprising" and its variations are open-ended, meaning "including but not limited to"; the term "based on" means "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; and the term "optionally" means "optional embodiments". Definitions of other terms will be given in the description below. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0037] In related technologies, laser galvanometer technology is often used to weld water-cooled plates during the laser water-cooled plate welding process. Although it has fewer pores, it has more spatter, slower welding speed, and poor consistency of weld penetration, resulting in a lot of rework and repairs.

[0038] This embodiment provides a laser welding device and method for aluminum alloy water-cooled plates.

[0039] like Figure 1As shown, an embodiment of the present invention provides a laser welding device for aluminum alloy water-cooled plates, including a laser 1, a water-cooled plate laser head 2, and a welding machine tool, as follows: Figure 2 As shown, the water-cooled plate laser head 2 includes a laser galvanometer and a multi-spot beam splitter assembly 22 arranged sequentially along the laser transmission direction; wherein,

[0040] The laser galvanometer is used to make the laser 11 emitted by the laser 1 oscillate in a spiral motion;

[0041] The multi-spot beam splitting assembly 22 is used to split the laser 11 into beams;

[0042] The welding machine tool is connected to the water-cooled plate laser head to drive the movement of the water-cooled plate laser head.

[0043] The welding machine and laser galvanometer work together to form a welding pattern on the aluminum alloy water-cooled plate 4 with multiple laser spots simultaneously oscillating in a spiral motion.

[0044] Specifically, laser 1 can be a Trumpf TruFiber 6001 S (FD45) laser with a minimum spot diameter of 100 micrometers and an output power of 6 kW.

[0045] The laser galvanometer is a device that dynamically adjusts the spatial position of the laser beam using a group of mirrors. Specifically, it can be implemented using a two-dimensional planar galvanometer in conjunction with a focusing lens 215. The mirror group can be driven by a motor to rotate, thereby changing the incident angle and focusing position of the laser beam. This component dynamically adjusts the laser's effective area, preventing excessive energy concentration that could lead to material vaporization and spatter. The multi-spot beam splitting component 22 is an optical system that decomposes a single laser beam into multiple independent spots. Specifically, it can be implemented using diffractive optical elements or a beam splitter prism, creating a spatially distributed multi-focal path by altering the beam propagation path. This component disperses the laser energy density, reducing localized overheating in the molten pool and suppressing porosity formation.

[0046] Specifically, the high-power beam output from laser 1 undergoes a helical oscillation via a galvanometer system, and a beam splitter decomposes the oscillating beam into multiple sub-spots. The welding machine tool moves the water-cooled laser head 2 along a preset trajectory, and the galvanometer system adjusts the oscillation phase and amplitude of each sub-spot in real time, forming a spatially uniform dynamic welding pattern. The coordinated movement of the multiple spots ensures a uniform heat input distribution in both time and space, maintaining a stable flow in the molten pool and effectively reducing spatter generation. The helical oscillation trajectory prolongs the interaction time between the laser and the material, promoting gas escape from the molten pool, while the energy superposition effect of the multiple spots ensures the achievement of the desired weld depth.

[0047] Among them, such as Figure 1As shown, the welding machine tool includes a machine tool controller 32 and machine tool guideways connected by a control cable 31. The machine tool guideways include an X-axis guideway 331, a Y-axis guideway 332, and a Z-axis guideway 333. The X-axis guideway 331 and the Y-axis guideway 332 are dynamically connected, and the Y-axis guideway 332 can move along the X-axis guideway 331. The Y-axis guideway 332 and the Z-axis guideway 333 are dynamically connected, and the Z-axis guideway 333 can move along the Y-axis guideway 332. The water-cooled plate laser head 2 is slidably mounted on the Z-axis guideway 333. The machine tool controller 32 controls the water-cooled plate laser head 2 to move along a preset trajectory via the X-axis guideway 331, the Y-axis guideway 332, and the Z-axis guideway 333.

[0048] In this embodiment, the laser achieves spiral oscillation through a laser galvanometer. Laser galvanometer welding technology is employed to thoroughly stir the molten pool, enabling rapid gas escape from the keyhole and eliminating porosity. Furthermore, a multi-spot beam splitting component 22 is added to achieve beam splitting. Driven by the welding machine tool, the laser head 2 of the water-cooled plate moves, and the laser galvanometer's stirring action forms a pattern of multiple spots spirally oscillating simultaneously on the weld bead of the water-cooled plate. This allows for simultaneous multi-point welding on the water-cooled plate surface, expanding the spot distribution range, increasing the stirring rate of the weld penetration, facilitating gas escape, effectively suppressing porosity, and reducing the porosity of the weld bead. The porosity density can be reduced to only one pore per 2000 square meters, improving the airtightness of the water-cooled plate. The multi-spot spiral oscillation mode effectively disperses the heat input energy, avoiding material vaporization caused by localized overheating, while ensuring sufficient penetration of the molten pool. This improves the back-side weld formation quality, contributing to enhanced welding quality and weld penetration stability. Moreover, the distance and direction between the multiple spots can be adjusted to suit different weld width requirements, demonstrating high practical production application value.

[0049] Optionally, such as Figure 2 As shown, the laser galvanometer includes a planar two-dimensional galvanometer and a focusing mirror 215. The planar two-dimensional galvanometer includes a laser X-axis reflecting mirror assembly and a laser Z-axis correcting reflecting mirror assembly. The laser X-axis reflecting mirror assembly and the laser Z-axis correcting reflecting mirror assembly are used to rotate according to the position of the aluminum alloy water-cooled plate 4 and the direction of the laser to guide the laser to the focusing mirror 215.

[0050] In this optional embodiment, a planar two-dimensional dynamic adjustment system is established through orthogonally arranged dual-mirror assemblies, allowing the beam projection angle to be simultaneously controlled by X-axis position compensation and Z-axis perpendicularity correction. Compared to a single-axis adjustment system, this structure can match the spatial pose changes of the water-cooled plate in real time, eliminating the problem of uneven energy density distribution caused by beam incident angle deviation. It achieves dynamic coordinated control of the laser beam projection angle and focal point position during welding, effectively suppressing penetration depth fluctuations caused by beam deflection during high-speed welding. The linkage adjustment mechanism of the dual-axis mirrors reduces excessive concentration of laser energy at the edge of the molten pool, reducing the generation of metal vapor sputtering. The real-time pose compensation function of the planar two-dimensional galvanometer ensures a stable penetration depth even when welding speed increases, avoiding back penetration or incomplete fusion defects. The stable focusing effect of the focusing lens 215 ensures the consistency of energy density at each point within the helical oscillation trajectory, thereby improving the uniformity of the weld structure.

[0051] The planar two-dimensional galvanometer refers to a two-dimensional optical system composed of two independent mirrors. Specifically, it can be implemented using mirror assemblies orthogonally arranged along the X and Z axes. The projection angle of the laser beam in the plane is adjusted via a motor and dual-axis linkage. The focusing lens 215 is an optical element that converges the diverging laser beam into a high-energy-density spot. Specifically, it can be implemented using an aspherical lens or a combination of lenses to form a stable focal point on the workpiece surface. The laser X-axis reflecting mirror assembly is a mechanism that adjusts the beam deflection along the welding direction. Specifically, it can be implemented using a direct connection structure between the mirror and a rotary motor to compensate for dynamic offsets in the plane position of the water-cooled plate. The laser Z-axis correction reflecting mirror assembly is a mechanism that adjusts the beam incident angle perpendicular to the workpiece surface. Specifically, it can be implemented using a closed-loop control reflecting mirror with an angle sensor to correct the perpendicularity deviation between the laser beam and the welding surface in real time.

[0052] Specifically, the laser X-axis oscillating motor 212 controls the rotation of the laser X-axis reflector 211, and the laser Z-axis correction motor 214 controls the rotation of the laser Z-axis correction reflector 213, generating a composite motion trajectory that allows the laser beam to form a spiral scanning path on the aluminum alloy surface. The laser X-axis reflector assembly changes the X-axis reflection angle through real-time rotation, offsetting the influence of the water-cooled plate position deviation on the beam projection point during the movement of the welding machine tool. The laser Z-axis correction reflector assembly synchronously adjusts the Z-axis reflection angle to ensure that the incident direction of the laser beam is always perpendicular to the dynamically changing welding surface. The dual-axis reflectors of the planar two-dimensional galvanometer maintain an orthogonal relationship during movement, causing the beam deflection to form a vector superposition in the XZ plane. The focusing lens 215 precisely focuses the dual-axis adjusted laser beam onto the target welding area, maintaining the stability of the focal point position in the thickness direction of the plate. This dual-axis dynamic compensation mechanism homogenizes the laser energy distribution and avoids molten pool morphology distortion caused by beam deflection.

[0053] Optionally, such as Figure 2 As shown, the laser galvanometer also includes a collimation mechanism 216, through which the laser 11 emitted by the laser 1 reaches the planar two-dimensional galvanometer.

[0054] In this optional embodiment, by integrating the collimation mechanism 216 inside the laser galvanometer, the optical path transmission distance is shortened. Simultaneously, collimation processing ensures the beam reaches optimal collimation before reflection by the galvanometer, significantly improving the control accuracy and welding stability of the galvanometer system. This solves the problem of decreased welding quality caused by laser beam divergence during transmission. Through the synergistic effect of the collimation mechanism 216 and the planar two-dimensional galvanometer, high-precision directional control of the laser beam is achieved, effectively improving the consistency of weld penetration and reducing welding defects caused by beam deviation.

[0055] The collimation mechanism 216 is a device used to adjust the divergence angle of the laser beam. It can be implemented using a lens group or a combination of mirrors. Its function is to maintain the parallelism of the laser beam during transmission and reduce the impact of beam divergence on subsequent optical systems. The planar two-dimensional galvanometer is a two-dimensional deflection system composed of mirror assemblies. It can be implemented using a motor-driven mirror assembly. Its function is to achieve precise deflection control of the laser beam in a plane through dynamic adjustment of the mirror angle.

[0056] Specifically, the original laser beam output from laser 1 is processed by collimation mechanism 216, which effectively compresses the divergence angle, forming a highly parallel beam. This beam then enters the planar two-dimensional galvanometer system, where the rapid deflection of the mirrors enables the directional movement of the laser beam within the welding area. The introduction of collimation mechanism 216 eliminates the divergence effect during laser transmission, ensuring that the beam maintains a stable spot size and energy distribution before reflection by the galvanometer, thereby improving the deflection accuracy of the planar two-dimensional galvanometer for the laser beam.

[0057] Optionally, such as Figure 2 As shown, the laser X-axis reflector assembly includes a connected laser X-axis reflector 211 and a laser X-axis oscillating motor 212, which controls the rotation of the laser X-axis reflector 211. The laser Z-axis correction reflector assembly includes a connected laser Z-axis correction reflector 213 and a laser Z-axis correction motor 214, which controls the rotation of the laser Z-axis correction reflector 213.

[0058] In this optional embodiment, by configuring independent drive motors for the X-axis and Z-axis reflectors, the error transmission path of the linkage mechanism is eliminated, improving the response speed of reflector angle adjustment to the millisecond level, while controlling the spot positioning accuracy within ±5μm. This effectively solves the spatter problem caused by insufficient dynamic adjustment accuracy of the laser galvanometer, improving the stability of the molten pool during welding, and reducing the weld depth fluctuation range from ±0.3mm in the traditional solution to ±0.1mm. The synchronous correction function avoids optical path deviation caused by machine tool movement, reducing the porosity defect rate to below 2%, meeting the process requirements of high-speed welding of aluminum alloy water-cooled plates.

[0059] The laser X-axis oscillation motor 212 is a servo actuator that drives the reflector to deflect in the X-axis direction. It can be implemented using a high-response stepper motor or voice coil motor, achieving micron-level adjustment precision of the reflector angle through a closed-loop control system. The laser Z-axis correction motor 214 is an adjustment mechanism that drives the reflector to compensate for optical path offset in the Z-axis direction. It can be implemented using a DC servo motor with an encoder, dynamically correcting the position by real-time feedback of the relative position changes between the welding head and the workpiece.

[0060] Specifically, during high-speed welding, the X-axis laser oscillation motor 212 drives the reflector to reciprocate at high frequency according to a preset spiral oscillation trajectory, causing the laser beam to form a transverse scanning motion on the aluminum alloy surface. Simultaneously, the Z-axis laser correction motor 214 adjusts the reflector tilt angle based on the machine tool guide rail displacement data to compensate for longitudinal optical path offset caused by welding head movement. The coordinated control of the two motors ensures that the laser focus point remains at the set position, avoiding molten pool disturbance caused by spot deviation. By independently controlling the X-axis and Z-axis reflector angles, precise path control of the laser beam in three-dimensional space is achieved.

[0061] Optionally, the laser 1 and the water-cooled plate laser head 2 are connected by an optical fiber 12, the core diameter of which is 50 to 100 μm and the cladding diameter of which is 200 to 400 μm.

[0062] In this optional embodiment, a fiber laser 11 with a core diameter of 50 to 100 μm and a cladding diameter of 200 to 400 μm is used to achieve high-power welding. The choice of laser spot size is determined by the dense oxide layer on the aluminum alloy surface, and since the aluminum alloy water-cooled plate 4 is a highly reflective material, a high-density energy laser 11 is required to penetrate the aluminum alloy surface. Therefore, a welding spot of 50-100 micrometers is selected for effective welding. Experiments show that the welding speed is directly proportional to the energy density of the laser spot; the smaller the spot, the lower the required laser power at the same speed. Using a reasonably priced 100-micrometer spot diameter is the best cost-performance choice. By limiting the specific range of core and cladding diameters, the beam quality's control over the dynamic behavior of the molten pool is optimized while ensuring high energy transmission efficiency. It achieves precise control of the heat input of the molten pool during high-speed welding of aluminum alloy water-cooled plates, significantly reducing the phenomenon of inconsistent penetration depth caused by uneven energy distribution. At the same time, it reduces porosity defects in the welding area by stabilizing the beam transmission characteristics, thereby meeting the stringent requirements for weld quality and airtightness under high-speed welding conditions.

[0063] The fiber core diameter refers to the size of the core region that transmits laser energy (11). It can be achieved using core diameter processing techniques for ytterbium-doped fiber or silica fiber. The core diameter directly affects the energy density distribution of the laser beam. The fiber cladding diameter (12) refers to the outer diameter of the dielectric layer surrounding the fiber core. It can be achieved by controlling the cladding thickness through the fiber drawing process (12). The matching design of the cladding diameter is used to constrain the beam mode and reduce transmission loss.

[0064] Specifically, when the fiber core diameter is controlled within the range of 50 to 100 μm, the energy concentration of laser 11 can reach the threshold required to penetrate the aluminum alloy water-cooled plate 4. This avoids spatter caused by excessively high local energy due to an excessively small fiber core, or insufficient penetration due to energy dispersion caused by an excessively large fiber core. Setting the cladding diameter of fiber 12 to 200 to 400 μm effectively suppresses high-order mode excitation during beam transmission, maintaining the stable transmission characteristics of the Gaussian beam, thereby reducing molten pool fluctuations caused by beam distortion during welding. The coordinated design of the fiber core and cladding diameters ensures that the laser 11 energy remains uniformly distributed during transmission, forming a stable heat input when applied to the workpiece, thus suppressing porosity formation and improving the consistency of penetration depth.

[0065] Optionally, the laser 11 emitted by the laser 1 is a ring-shaped spot.

[0066] In this optional embodiment, the presence of the ring spot can suppress spatter generation. When using ring spot technology in aluminum alloy welding, and in the laser welding verification of steel materials, the ring spot technology keeps the small hole formed by the laser welding continuously open during welding, which helps reduce spatter. The ring core power ratio can be arbitrarily adjusted; different ratios can accommodate different welding spatter at different speeds. This effectively reduces spatter during high-speed welding, improves the consistency of weld penetration, and simultaneously reduces the probability of porosity formation by enhancing the dynamic stirring effect of the molten pool, thereby improving the welding quality and airtightness of the aluminum alloy water-cooled plate 4.

[0067] The annular spot refers to the spatially annular distribution of laser energy 11. This can be achieved using diffractive optical elements or a special fiber optic structure 12. By adjusting the parameters of the optical elements, a ring-shaped energy distribution with low energy at the center and high energy at the periphery is formed. The low-energy region at the center suppresses overheating in the molten pool center, while the high-energy region at the periphery maintains the stability of the melt depth.

[0068] Specifically, the circumferentially symmetrical energy distribution of the annular laser spot creates a dynamic thermal equilibrium within the molten pool. The reduced energy density in the central region decreases violent boiling, thus suppressing spatter. The high-energy peripheral region continuously acts on the edge of the molten pool, ensuring consistent penetration depth of the aluminum alloy material at a thickness of 2-3 mm. The rotational symmetry of the annular laser spot enhances metal flow within the molten pool, lengthens the escape path of bubbles, and promotes the full removal of bubbles before solidification, reducing the probability of porosity formation.

[0069] Optionally, such as Figure 1 As shown, the welding machine tool includes a machine tool controller 32 and a machine tool guide rail connected by a control cable 31. The machine tool guide rail includes a machine tool X guide rail 331, a machine tool Y guide rail 332 and a machine tool Z guide rail 333.

[0070] In this optional embodiment, CNC machine tools are used for programming, and different weld patterns and weld trajectories are created according to different products, which can realize rapid product switching and greatly improve product flexibility.

[0071] This application achieves precise positioning of the laser 11 focal points in three-dimensional space, solving the problem of inconsistent penetration depth caused by insufficient machine tool motion accuracy; it suppresses the generation of welding spatter through dynamic height compensation; at the same time, the three-axis coordinated motion mechanism breaks through the speed limit of traditional equipment, enabling the welding speed to be significantly improved while maintaining high precision.

[0072] The machine tool controller 32 is an electronic device used to generate motion control commands. It can be implemented using a numerical control system or a programmable logic controller (PLC). It generates three-axis coordinated motion signals by parsing welding path parameters. The X-axis guide rail 331 is a linear motion mechanism arranged along the length of the workpiece. It can be implemented using a ball screw or linear motor drive structure and is used to control the lateral displacement of the laser head in the plane. The Y-axis guide rail 332 is a linear motion mechanism arranged along the width of the workpiece. It can be implemented using a sliding platform structure orthogonally mounted to the X-axis guide rail and is used to achieve longitudinal positioning of the laser head in the plane. The Z-axis guide rail 333 is a lifting mechanism perpendicular to the workpiece surface. It can be implemented using a precision slide structure driven by a servo motor and is used to adjust the distance between the laser focus and the workpiece surface in real time. The control cable 31 is a connecting harness for transmitting electrical signals and data commands. It can be implemented using shielded twisted-pair cable or fiber optic communication lines, and its anti-interference design ensures the real-time performance and accuracy of motion commands.

[0073] Specifically, the machine tool controller 32 sends pulse signals to the three-axis guide rails via control cable 31, driving the X / Y guide rails to achieve planar positioning, while the Z guide rail synchronously adjusts the laser focus height. During high-speed welding, the three-axis guide rails form a closed-loop feedback system, using position sensors to monitor the laser head coordinate deviation in real time, and the controller dynamically corrects the motion trajectory. When the welding path exhibits complex curves, the X / Y axes achieve coordinated movement using interpolation algorithms, while the Z axis performs adaptive height compensation based on the molten pool morphology feedback. This precise three-dimensional linkage control mechanism ensures that the laser focus remains at the set welding position during high-speed movement, avoiding weld depth fluctuations caused by mechanical vibration or inertial offset, while simultaneously suppressing spatter by stabilizing the focus height.

[0074] Optionally, such as Figure 1 As shown, the water-cooled plate laser head 2 is mounted on the machine tool guide rail, and the machine tool controller 32 is used to control the machine tool guide rail to move the water-cooled plate laser head 2.

[0075] In this optional embodiment, through the synergistic effect of the multi-axis guide rail and the closed-loop control system, real-time correction of the laser head motion trajectory is achieved for the first time in the field of aluminum alloy water-cooled plate 4 welding, solving the problems of unstable penetration depth and spatter control in high-speed welding scenarios. It effectively suppresses penetration depth fluctuations caused by laser head displacement deviation during high-speed welding, keeping the penetration depth of the aluminum alloy water-cooled plate 4 weld within the set range. The improved welding trajectory accuracy makes the heat input distribution formed by the multi-spot spiral oscillation more uniform, significantly reducing the generation of metal spatter. Simultaneously, the closed-loop control mechanism can automatically compensate for focus shift caused by mechanical vibration, preventing the welding path from deviating from the preset trajectory and ensuring consistent welding quality.

[0076] The machine tool guideway refers to a mechanical guiding structure that includes three motion directions (X, Y, and Z). It can be implemented using a combination of ball screws and linear motors, providing the laser head with translational freedom in three-dimensional space through multi-axis linkage. The machine tool controller 32 refers to a CNC system with motion trajectory planning and closed-loop control functions. It can be implemented using a PLC or embedded controller combined with a servo driver. By receiving position feedback signals in real time and outputting drive commands, it ensures that the laser head's movement trajectory matches the preset welding path.

[0077] Specifically, the physical connection between the laser head and the machine tool guide rail allows for precise displacement along the X, Y, and Z axes. The machine tool controller 32 sends pulse signals to the drive mechanisms along each axis based on the coordinate data generated by the welding program, driving the guide rails to perform composite motions on the laser head. During welding, the controller monitors the laser head position in real time via an encoder. When mechanical vibration or inertia-induced offset is detected, the drive signals are immediately adjusted to compensate for the error. This closed-loop control mechanism ensures that the laser focus remains aligned with the welding area of ​​the aluminum alloy water-cooled plate 4, guaranteeing the trajectory accuracy of the multi-spot spiral oscillating welding pattern. By eliminating positioning deviations during high-speed movement, the amplitude of weld penetration fluctuations is significantly reduced, while also minimizing metal spatter caused by focus offset.

[0078] In this optional embodiment, the laser power of laser 11 is optionally 4500 to 4900W, the welding speed is 5 to 15mm / s, and the stirring frequency of laser 11 is 80 to 120Hz.

[0079] In this optional embodiment, the stirring frequency is increased to over 80Hz, significantly enhancing the molten pool disturbance effect. During the welding of the aluminum alloy water-cooled plate 4, the penetration depth fluctuation range is reduced to less than 0.2mm, the porosity defect rate is reduced to less than one-third of the industry standard, and the welding efficiency is increased to twice that of traditional galvanometer technology. The back-penetration defect rate on the weld back side is reduced from over 15% to less than 3%, and the spatter particle size is reduced to less than 50 micrometers, meeting the stringent requirements of the water-cooled plate airtightness test.

[0080] The laser power refers to the energy intensity output by laser 1, which can be achieved using a continuous fiber laser 1. The power range is controlled by adjusting the current and modulation frequency. This power range is sufficient to break through the oxide layer on the aluminum alloy surface to form a stable molten pool, while avoiding excessive energy that could cause molten metal spatter. The welding speed refers to the rate at which the laser spot moves relative to the workpiece, which can be achieved using the servo motor drive system of the CNC machine tool. This speed range improves processing efficiency while ensuring weld quality. The laser stirring frequency refers to the rate at which the laser beam oscillates periodically, which can be achieved using the scanning motor of the galvanometer system. High-frequency oscillation alters the laser trajectory, promoting molten pool flow and bubble escape.

[0081] Specifically, a laser power of 4500 to 4900 W is matched with the thermal conductivity of the aluminum alloy material, controlling the heat input while achieving effective weld penetration. When the welding speed is maintained at 5 to 15 mm / s, the solidification time of the molten pool and the metal flow reach a dynamic balance, avoiding weld penetration fluctuations caused by excessive speed. A stirring frequency of 80 to 120 Hz periodically disturbs the molten pool, causing a swirling effect in the molten metal and accelerating the upward expulsion of bubbles. The synergistic effect of these three parameters forms a stable process window under high-speed welding conditions, suppressing porosity formation and maintaining the consistency of weld formation.

[0082] In this optional embodiment, such as Figure 3 As shown, another embodiment of the present invention provides a laser welding method for aluminum alloy water-cooled plates, based on the aluminum alloy water-cooled plate laser welding apparatus described above, including the following steps:

[0083] S1: Laser 11 is emitted by laser 1, and laser mirror makes laser 11 oscillate in a spiral motion;

[0084] S2: The multi-spot beam splitting assembly 22 splits the laser 11 into beams, and through the action of the welding machine tool and the laser galvanometer, it forms a welding pattern on the aluminum alloy water-cooled plate 4 with multiple beams simultaneously spiraling.

[0085] In this embodiment, a distributed heat source is formed by multi-spot spiral oscillation, maintaining the uniformity of the molten pool during high-speed movement. Existing technologies cannot achieve dynamic superposition control of multi-spot trajectories, making it difficult to simultaneously achieve welding speed and penetration stability. This effectively suppresses molten pool spatter and porosity formation during high-speed welding, solves the problem of back-side defects caused by inconsistent penetration depth, and ensures weld airtightness meets requirements while increasing welding speed, satisfying the industrialization needs of replacing brazing processes for aluminum alloy water-cooled plates.

[0086] The spiral oscillation of the laser galvanometer refers to controlling the deflection angle of the laser beam in the X and Z directions through the reflector assembly of the planar two-dimensional galvanometer, forming a spiral trajectory laser motion path. This can be achieved by continuously rotating the reflector driven by a servo motor. This action disperses the concentration of laser energy in the welding area. The multi-spot beam splitting assembly 22 forms multiple spots that simultaneously spiral oscillate, which means decomposing a single laser beam into two or more independent spots. This can be achieved using beam splitters or diffractive optical elements. Each beam spot maintains a synchronous spiral motion trajectory under the drive of the galvanometer, creating a superimposed composite thermal field in the welding area. The coordinated action of the welding machine tool and the laser galvanometer refers to synchronously controlling the machine tool guide rail movement speed and the galvanometer oscillation frequency through a CNC system. This can be achieved by using a closed-loop feedback system to adjust the spot position offset in real time. This coordinated mechanism ensures the positioning accuracy of the spot trajectory during high-speed movement.

[0087] Specifically, the laser beam forms a ring-shaped heat input region during its helical oscillation, effectively reducing the energy density per unit area and suppressing spatter and bubble retention caused by violent boiling of the molten pool. The multiple laser spots after beam splitting are distributed with the same helical radius and phase difference, forming periodically overlapping welding paths on the aluminum alloy surface, maintaining molten pool stability through the thermal field superposition effect. When the machine tool guide rail drives the laser head to move uniformly along the weld direction, the galvanometer oscillation frequency matches the moving speed, keeping the spacing between adjacent helical paths constant and avoiding fluctuations in weld depth. The parallel action of multiple laser spots expands the weld width, allowing a larger welding area to be covered per unit time, breaking through the welding speed limitations of a single laser spot.

[0088] The present invention will be further described below with reference to specific embodiments.

[0089] Example 1: Laser welding of four-spot aluminum alloy water-cooled plates, based on the aluminum alloy water-cooled plate laser welding device described above.

[0090] 1. Laser is emitted by laser 1, and the laser galvanometer makes the laser oscillate in a spiral motion;

[0091] Laser 1 is a Trumpf TruFiber 6001S (FD45) laser with a minimum spot diameter of 100 micrometers and an output power of 6 kW. Specific laser parameters are shown in Table 1. The optical fiber is a 100 / 400 micrometer fiber. The welding machine tool machining center operates at a speed of 10 m / min with an interpolation accuracy of 0.08 mm. The verification material used is 2×1.5M AA5754 material with a thickness of 1.5 mm. The laser head has a 1:2 aspect ratio and a focal length of 200 mm.

[0092] Table 1. Laser Specific Parameters

[0093]

[0094] 2. A four-spot beam splitter is used to split the laser beam into four spots. The beam pattern after splitting is as follows: Figure 4 As shown, the spacing between light spots is as follows Figure 5 As shown, the weld width is as follows Figure 6 As shown, the weld width reaches 2mm; through the movement of the welding machine and laser galvanometer, multiple laser spots are simultaneously spirally oscillating on the aluminum alloy water-cooled plate, as shown in the image. Figure 7 As shown in the image. Cross-sectional images of the molten pool during laser welding are shown below. Figure 8 As shown, the laser welding process parameters are: P=4500 W, indicating that the laser power is 4500 watts; Pcore=50%, indicating that the laser core power accounts for 50%; v=8 m / min, the welding speed is 8 meters per minute; FL=0mm, the focusing length is 0 millimeters. Figure 8It is evident that Embodiment 1 facilitates the overflow of pores and reduces the porosity of the weld.

[0095] Example 2: Laser welding of four-spot aluminum alloy water-cooled plate.

[0096] 1. Laser is emitted through laser 1;

[0097] Laser 1 is a Trumpf TruFiber 6001S (FD45) laser with a minimum spot diameter of 100 micrometers and an output power of 6 kW. Specific laser parameters are shown in Table 1. The optical fiber is a 100 / 400 micrometer fiber. The welding machine tool machining center operates at a speed of 10 m / min with an interpolation accuracy of 0.08 mm. The verification material used is 2×1.5M AA5754 material with a thickness of 1.5 mm. The laser head has a 1:2 aspect ratio and a focal length of 200 mm.

[0098] 2. A four-spot beam splitter is used to split the laser beam. The laser welding process parameters are as follows: P=4500W, which means the laser power is 4500 watts; Pcore=50%, which means the core power of the laser accounts for 50%; v=8 m / min, which means the welding speed is 8 meters per minute; FL=0 mm, which means the focusing length is 0 millimeters.

[0099] Comparative Example 1: Laser welding of single-spot aluminum alloy water-cooled plate.

[0100] 1. Emitting laser light through a laser device;

[0101] The laser selected is a Trumpf TruFiber 6001S (FD45) laser with a minimum spot diameter of 100 micrometers and an output power of 6 kW. Specific laser parameters are shown in Table 1. The optical fiber is 100 / 400 micrometer fiber. The welding machine tool machining center operates at a speed of 10 m / min with an interpolation accuracy of 0.08 mm. The verification material used is 2×1.5M AA5754 steel with a thickness of 1.5 mm. The laser head has a 1:2 aspect ratio and a focal length of 200 mm.

[0102] 2. Through the movement of the welding machine and laser galvanometer, a welding pattern with a spiral oscillating laser spot is formed on the aluminum alloy water-cooled plate, such as... Figure 9 As shown in the image. Cross-sectional images of the molten pool during laser welding are shown below. Figure 10 As shown, the laser welding process parameters are: P=3000 W, indicating that the laser power is 3000 watts; Pcore=40%, indicating that the laser core power accounts for 40%; v=8m / min, the welding speed is 8 meters per minute; FL=0 mm, the focusing length is 0 millimeters.

[0103] Comparative Example 2: Laser welding of single-spot aluminum alloy water-cooled plate.

[0104] 1. Emitting laser light through a laser device;

[0105] The laser selected is a Trumpf TruFiber 6001S (FD45) laser with a minimum spot diameter of 100 micrometers and an output power of 6 kW. Specific laser parameters are shown in Table 1. The optical fiber is 100 / 400 micrometer fiber. The welding machine tool machining center operates at a speed of 10 m / min with an interpolation accuracy of 0.08 mm. The verification material used is 2×1.5M AA5754 steel with a thickness of 1.5 mm. The laser head has a 1:2 aspect ratio and a focal length of 200 mm.

[0106] The products prepared in Examples 1-2 and Comparative Examples 1-2 were subjected to the performance tests shown in Table 2. The test results are shown in Table 2.

[0107] Table 2. Relevant parameters of the products prepared in Examples 1-2 and Comparative Examples 1-2

[0108]

[0109] As shown in Table 2, the use of multi-spot composite laser galvanometer technology significantly reduces porosity in the weld pool and improves the airtightness of the water-cooled plate. Spatter is greatly reduced, welding speed is increased, which is beneficial for improving welding quality and penetration stability, resulting in a wider weld width and enhanced weld joint strength.

[0110] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. An aluminum alloy water-cooled plate laser welding apparatus characterized by comprising: The laser (1), the water-cooled plate laser head (2) and the welding machine tool are included; The water-cooled plate laser head (2) includes a laser galvanometer and a multi-spot beam splitting assembly (22) arranged in sequence along the laser transmission direction; wherein the laser galvanometer is used to make the laser (11) emitted by the laser (1) realize spiral swing; the multi-spot beam splitting assembly (22) is used to split the laser (11) into multiple spots; The welding machine tool is connected with the water-cooled plate laser head (2) and is used to drive the water-cooled plate laser head (2) to move: The welding machine tool and the laser galvanometer are used to cooperate to form a plurality of spot welding patterns on the aluminum alloy water-cooled plate (4) at the same time; The split multi-spot is distributed with the same spiral radius and phase difference to form a periodic overlapping welding path on the aluminum alloy surface, and the stability of the molten pool is maintained through the thermal field superposition effect; The laser power of the laser (11) is 4500 to 4900 W, the welding speed is 5 to 15 mm / s, and the laser (11) stirring frequency is 80 to 120 Hz.

2. The aluminum alloy water-cooled plate laser welding apparatus according to claim 1, characterized by, The laser galvanometer includes a planar two-dimensional galvanometer and a focusing mirror (215), the planar two-dimensional galvanometer includes a laser X-direction mirror assembly and a laser Z-direction correction mirror assembly, the laser X-direction mirror assembly and the laser Z-direction correction mirror assembly are used to rotate according to the position of the aluminum alloy water-cooled plate (4) and the direction of the laser (11) to guide the laser (11) to the focusing mirror (215).

3. The aluminum alloy water cold plate laser welding apparatus of claim 2, wherein, The laser galvanometer also includes a collimation mechanism (216), and the laser (11) emitted by the laser (1) reaches the planar two-dimensional galvanometer through the collimation mechanism (216).

4. The aluminum alloy water-cooled plate laser welding apparatus of claim 2, wherein, The laser X-direction mirror assembly includes a connected laser X-direction mirror (211) and a laser X-direction swing motor (212), the laser X-direction swing motor (212) is used to control the rotation of the laser X-direction mirror (211), and the laser Z-direction correction mirror assembly includes a connected laser Z-direction correction mirror (213) and a laser Z-direction correction motor (214), the laser Z-direction correction motor (214) is used to control the rotation of the laser Z-direction correction mirror (213).

5. The aluminum alloy water cold plate laser welding apparatus of claim 1, wherein, The laser (1) is connected with the water-cooled plate laser head (2) through an optical fiber (12), the core diameter of the optical fiber (12) is 50 to 100 μm, and the cladding diameter of the optical fiber (12) is 200 to 400 μm.

6. The aluminum alloy water cold plate laser welding apparatus of claim 1, wherein, The laser (11) emitted by the laser (1) is a ring-shaped spot.

7. The aluminum alloy water cold plate laser welding apparatus of claim 1, wherein, The welding machine tool includes a machine tool controller (32) and a machine tool guide rail connected through a control cable (31), and the machine tool guide rail includes a machine tool X-direction guide rail (331), a machine tool Y-direction guide rail (332) and a machine tool Z-direction guide rail (333).

8. The aluminum alloy water cold plate laser welding apparatus of claim 7, wherein, The water-cooled plate laser head (2) is arranged on the machine tool guide rail, and the machine tool controller (32) is used to control the machine tool guide rail to move the water-cooled plate laser head (2).

9. An aluminum alloy water-cooled plate laser welding method based on the aluminum alloy water-cooled plate laser welding apparatus according to any one of claims 1 to 8, characterized by, The steps include: S1: emitting laser (11) by laser (1), and making the laser (11) realize spiral swing by laser galvanometer; S2: the multi-spot beam splitting assembly (22) splits the laser (11) into multiple spots, and through the action of the welding machine tool and the laser galvanometer, a welding pattern of multiple spots spirally oscillating at the same time is formed on the aluminum alloy water-cooled plate (4).

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