Laser welding method, device, equipment and computer-readable storage medium

Abstract

The present invention discloses a laser welding method, apparatus, equipment, and computer-readable storage medium, belonging to the field of laser welding technology. The present invention obtains the material to be welded and places it on a welding workbench. After determining the welding points according to a preset welding path, the laser parameters are adjusted in stages according to a preset number of welding stages to laser weld the material to obtain a welded alloy. Laser welding of dissimilar materials is achieved by adjusting the laser process parameters, thereby improving the welding quality of dissimilar materials.

Description

Technical Field

[0001] The present invention relates to the field of laser welding technology, and in particular to a laser welding method, device, equipment and computer-readable storage medium. Background Art

[0002] Welding, as an important method of connecting products, plays a vital role in the industrial field. Improving welding efficiency can further improve production efficiency. Laser welding, as an advanced welding technology, has a high degree of automation and an efficient and reliable welding process, which can effectively improve production efficiency.

[0003] Currently, welding of dissimilar materials is quite difficult because the absorption rates of dissimilar materials vary greatly during the welding process, and the energy required for welding is different. During the welding process, spattering, hole bursting, and difficulty in forming a stable molten pool will occur, making it impossible to form effective welding, resulting in poor quality of the final weld. Summary of the Invention

[0004] The main purpose of the present invention is to provide a laser welding method, device, equipment and computer-readable storage medium, aiming to improve the welding quality of dissimilar materials.

[0005] To achieve the above object, the present invention provides a laser welding method, which comprises the following steps:

[0006] Placing a material to be welded on a welding workbench, wherein the material to be welded is obtained by laminating a first raw material to be welded and a second raw material to be welded, which are different in material;

[0007] According to a preset welding path, a point to be welded is selected on the material to be welded, and a laser beam is aligned with the point to be welded;

[0008] Dividing the laser welding process into a preset number of welding stages, and setting a preset laser parameter adjustment method for each welding stage;

[0009] The points to be welded are welded based on the control signal to obtain a welding alloy after cooling and solidification.

[0010] Optionally, the step of dividing the laser welding process into a preset number of welding stages includes:

[0011] Set the welding cycle, and set the peak energy value, initial stable welding value, stable welding threshold and solidification threshold;

[0012] Based on the peak energy value, the initial stable welding value, the stable welding threshold and the solidification threshold, the welding cycle is divided into four welding stages, and the laser parameter adjustment methods of the four welding stages are set respectively, and the corresponding time of each stage is a first preset time, a second preset time, a third preset time and a fourth preset time.

[0013] Optionally, after the step of dividing the laser welding process into a preset number of welding stages, the method further comprises:

[0014] Dividing the welding cycle into a preset number of control points, each control point corresponding to a time point and a laser power;

[0015] Based on the peak energy value, the initial stable welding value, the stable welding threshold, the solidification threshold and the preset laser parameter adjustment method, the control point is selected to set the laser power of the four welding stages and generate corresponding control signals.

[0016] Optionally, the step of welding the points to be welded based on the control signal to obtain a welding alloy after cooling and solidification includes:

[0017] Turning on the laser, controlling the power of the laser to reach a peak energy value in a preset rapid increase manner within a first preset time, and then to reach an initial stable welding value in a preset rapid decrease manner after reaching the peak energy value;

[0018] After reaching the initial stable welding value, controlling the power of the laser to decrease to the stable welding threshold in a preset slow-down manner within a second preset time;

[0019] After reaching the stable welding threshold, controlling the power of the laser to decrease to the solidification threshold in a preset repeated rising and falling manner within a third preset time;

[0020] When the solidification threshold is reached, the power of the laser is controlled to slowly decrease within a fourth preset time until the power reaches 0, thereby obtaining a cooled and solidified welding alloy.

[0021] Optionally, the step of placing the material to be welded on a welding workbench, wherein the material to be welded is obtained by laminating a first raw material to be welded and a second raw material to be welded, both of different materials, includes:

[0022] Selecting a silver-copper alloy of a first preset thickness as the first raw material to be welded among the materials to be welded, wherein the first preset thickness must meet a preset upper material thickness range;

[0023] Selecting a tungsten-copper alloy of a second preset thickness as the second raw material to be welded in the materials to be welded, wherein the second preset thickness must meet a preset lower layer material thickness range;

[0024] The first raw material to be welded and the second raw material to be welded are pressed together according to the standard of silver-copper alloy on top and tungsten-copper on the bottom, and then placed on the welding workbench.

[0025] Optionally, the step of aligning the laser beam with the point to be welded includes:

[0026] When the laser beam emitted by the laser passes through the collimator and is incident on the galvanometer, the preset welding point is drawn on the horizontal and vertical coordinates of the galvanometer based on the preset industrial control signal.

[0027] Optionally, the laser is a QCW laser with a wavelength of 1070 nm and a pulse width of milliseconds.

[0028] In addition, to achieve the above-mentioned object, the present invention further provides a laser welding device, comprising:

[0029] A sample placement module is used to place a material to be welded on a welding workbench, wherein the material to be welded is obtained by laminating a first raw material to be welded and a second raw material to be welded, both of which are different in material;

[0030] A welding path module, configured to select a point to be welded on the material to be welded according to a preset welding path, and align the laser beam with the point to be welded;

[0031] A parameter setting module, configured to divide the laser welding process into a preset number of welding stages and to set a preset laser parameter adjustment method for each welding stage;

[0032] A control module, configured to generate corresponding control signals based on the welding stage and the laser parameter adjustment method;

[0033] The welding module is used to weld the points to be welded based on the control signal to obtain a welding alloy after cooling and solidification.

[0034] Optionally, the parameter setting module is further used to:

[0035] Set the welding cycle, and set the peak energy value, initial stable welding value, stable welding threshold and solidification threshold;

[0036] Based on the peak energy value, the initial stable welding value, the stable welding threshold and the solidification threshold, the welding cycle is divided into four welding stages, and the laser parameter adjustment methods of the four welding stages are set respectively, and the corresponding time of each stage is a first preset time, a second preset time, a third preset time and a fourth preset time.

[0037] Optionally, the parameter setting module is further used to:

[0038] Dividing the welding cycle into a preset number of control points, each control point corresponding to a time point and a laser power;

[0039] Based on the peak energy value, the initial stable welding value, the stable welding threshold, the solidification threshold and the preset laser parameter adjustment method, the control point is selected to set the laser power of the four welding stages and generate corresponding control signals.

[0040] Optionally, the welding module is further used to:

[0041] Turning on the laser, controlling the power of the laser to reach a peak energy value in a preset rapid increase manner within a first preset time, and then to reach an initial stable welding value in a preset rapid decrease manner after reaching the peak energy value;

[0042] After reaching the initial stable welding value, controlling the power of the laser to decrease to the stable welding threshold in a preset slow-down manner within a second preset time;

[0043] After reaching the stable welding threshold, controlling the power of the laser to decrease to the solidification threshold in a preset repeated rising and falling manner within a third preset time;

[0044] When the solidification threshold is reached, the power of the laser is controlled to slowly decrease within a fourth preset time until the power reaches 0, thereby obtaining a cooled and solidified welding alloy.

[0045] Optionally, the sample placement module is further used to:

[0046] Selecting a silver-copper alloy of a first preset thickness as the first raw material to be welded among the materials to be welded, wherein the first preset thickness must meet a preset upper material thickness range;

[0047] Selecting a tungsten-copper alloy of a second preset thickness as the second raw material to be welded in the materials to be welded, wherein the second preset thickness must meet a preset lower layer material thickness range;

[0048] The first raw material to be welded and the second raw material to be welded are pressed together according to the standard of silver-copper alloy on top and tungsten-copper on the bottom, and then placed on the welding workbench.

[0049] Optionally, the welding path module is further used to:

[0050] When the laser beam emitted by the laser passes through the collimator and is incident on the galvanometer, the preset welding point is drawn on the horizontal and vertical coordinates of the galvanometer based on the preset industrial control signal.

[0051] In addition, to achieve the above-mentioned purpose, the present invention also provides a laser welding device, which includes: a memory, a processor, and a laser welding program stored in the memory and executable on the processor, wherein the laser welding program is configured to implement the steps of the laser welding method described above.

[0052] In addition, to achieve the above-mentioned purpose, the present invention also provides a computer-readable storage medium, on which a laser welding program is stored. When the laser welding program is executed by a processor, the steps of the laser welding method described above are implemented.

[0053] The laser welding method, device, equipment and computer-readable storage medium proposed in the present invention obtain a material to be welded by pressing two raw materials to be welded, and place the material to be welded on a welding workbench. After determining the welding points according to a preset welding path, the laser parameters are adjusted in sections according to a preset number of welding stages to laser weld the material to be welded to obtain a welding alloy. The laser welding of dissimilar materials is achieved by adjusting the laser process parameters, thereby improving the welding quality of the dissimilar materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 Schematic diagram of the structure of the laser welding equipment in the hardware operating environment involved in the embodiment of the present invention;

[0055] Figure 2 This is a schematic flow chart of a first embodiment of the laser welding method of the present invention;

[0056] Figure 3 Schematic diagram of a laser welding device in one embodiment of the laser welding method of the present invention;

[0057] Figure 4 This is a detailed flow chart of step S30 in an embodiment of the laser welding method of the present invention;

[0058] Figure 5 This is a schematic diagram of a welding point waveform in an embodiment of the laser welding method of the present invention;

[0059] Figure 6 This is a detailed flow chart of step S10 in one embodiment of the laser welding method of the present invention;

[0060] Figure 7 This is a schematic diagram of material placement in an embodiment of the laser welding method of the present invention;

[0061] Figure 8 Schematic diagram of the functional modules of a laser welding device according to an embodiment of the present invention.

[0062] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0063] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0064] Reference Figure 1 , Figure 1 This is a schematic diagram of the laser welding equipment structure in the hardware operating environment involved in the embodiment of the present invention.

[0065] like Figure 1 As shown, the laser welding equipment may include: a processor 1001, such as a central processing unit (CPU), a communication bus 1002, a user interface 1003, a network interface 1004, and a memory 1005. Among them, the communication bus 1002 is used to realize the connection and communication between these components. The user interface 1003 may include a display screen (Display), an input unit such as a keyboard (Keyboard), and the user interface 1003 may optionally include a standard wired interface and a wireless interface. The network interface 1004 may optionally include a standard wired interface and a wireless interface (such as a wireless fidelity (WIreless-FIdelity, WI-FI) interface). The memory 1005 may be a high-speed random access memory (Random Access Memory, RAM) memory, or a stable non-volatile memory (Non-Volatile Memory, NVM), such as a disk memory. The memory 1005 may also be a storage device independent of the aforementioned processor 1001.

[0066] Those skilled in the art will understand that Figure 1 The structure shown in the figure does not constitute a limitation to the laser welding device, and may include more or less components than shown in the figure, or combine certain components, or arrange the components differently.

[0067] like Figure 1 As shown, the memory 1005 as a storage medium may include an operating system, a data storage module, a network communication module, a user interface module and a laser welding program.

[0068] exist Figure 1In the laser welding device shown, the network interface 1004 is mainly used for data communication with other devices; the user interface 1003 is mainly used for data interaction with the user; the processor 1001 and the memory 1005 in the laser welding device of the present invention can be set in the laser welding device, and the laser welding device calls the laser welding program stored in the memory 1005 through the processor 1001 and executes the laser welding method provided by the embodiment of the present invention.

[0069] The embodiment of the present invention provides a laser welding method, referring to Figure 2 , Figure 2 This is a schematic flow chart of a first embodiment of a laser welding method according to the present invention.

[0070] In this embodiment, the laser welding method includes:

[0071] Step S10, placing a material to be welded on a welding workbench, wherein the material to be welded is obtained by laminating a first raw material to be welded and a second raw material to be welded, which are different in material;

[0072] Step S20, selecting a point to be welded on the material to be welded according to a preset welding path, and aligning the laser beam at the point to be welded;

[0073] Step S30, dividing the laser welding process into a preset number of welding stages, and setting a preset laser parameter adjustment method for each welding stage;

[0074] Step S40, generating a corresponding control signal based on the welding stage and the laser parameter adjustment method;

[0075] Step S50: welding the points to be welded based on the control signal to obtain a weld alloy after cooling and solidification.

[0076] The laser welding method of this embodiment is used for laser welding. The reason why laser can be used as one of the processing means is because of its optical effect. The optical effects of laser mainly include photochemical reaction and photothermal effect. Laser processing is essentially the interaction between laser and matter. The interaction between laser and matter means that when the laser beam is projected onto the surface (or inside) of the material, part of the energy is reflected, part is absorbed, and part is transmitted. The light energy is absorbed in the form of vibration excitation of electrons and atoms, thereby causing energy transfer and transmission. The energy transfer and transmission causes various physical, chemical and biological effects and processes.

[0077] In laser welding, dissimilar materials often need to be welded. However, when welding dissimilar materials, welding defects are easily caused by the different absorption rates of the two materials. Therefore, the laser welding method of the present invention is proposed to improve the welding quality of dissimilar materials.

[0078] The following describes each step in detail:

[0079] Step S10, placing a material to be welded on a welding workbench, wherein the material to be welded is obtained by laminating a first raw material to be welded and a second raw material to be welded, which are different in material;

[0080] In one embodiment, the materials to be welded are first placed on a welding workbench. It should be noted that the materials to be welded are two materials with different material compositions, namely a first material to be welded and a second material to be welded.

[0081] Step S20, selecting a point to be welded on the material to be welded according to a preset welding path, and aligning the laser beam at the point to be welded;

[0082] In one embodiment, the preset welding path can be a weld point, a path, or a pattern. A path is composed of individual weld points. Therefore, the weld point to be welded is first selected based on the preset weld point path and the laser beam is aligned with the weld point. At this point, the laser has not yet emitted light. The control system sets the laser light path and aligns it with the weld point to be welded. The laser is then turned on and welding is performed.

[0083] Step S30, dividing the laser welding process into a preset number of welding stages, and setting a preset laser parameter adjustment method for each welding stage;

[0084] In one embodiment, the laser processing process can be divided into the following stages: material heat absorption, material heating, surface melting and vaporization, and cooling and solidification. Laser parameters are adjusted to address issues that may arise at different stages of laser processing. First, there is the material heating and melting process. After the laser is hit on the material, during the interaction between the laser and the material, part of the laser irradiated on the material is absorbed by the material, while the other part is reflected and transmitted by the material. Since there are many different materials that are also highly reflective materials with low laser absorption rates, high-energy lasers need to be set during the heating and melting process to break through the material's absorption threshold, causing the material to soften and melt due to the thermal influence of the welding heat input. After the material melts and vaporizes, a liquid metal part with a certain shape is formed on the weld, which is also the weld pool. However, during the laser welding process, due to the overburning of the lower melting point components in the alloy material, or the dissolution of too much gas in the vaporized metal plasma (including gas in the weld gap, air around the weld point, and shielding gas, etc.), these gases are precipitated during the rapid cooling and solidification process, but cannot escape from the molten pool quickly, so tiny bubbles are formed during the solidification process of the molten pool. Excessive pores will lead to poor strength or cracking of the weld. Therefore, during the molten pool stage, it is necessary to reasonably set the cooling rate, for example, to increase the heating time of the weld point to reduce the generation of pores. Therefore, it is best to set the preset number of welding stages to more than 2.

[0085] Specifically, the number of welding stages and the laser parameter settings for each stage need to be determined through experimentation. During the experiment, a high-speed camera is used to capture the welding process. By analyzing the images of the changes in the weld point over a period of tens of milliseconds, it is determined whether spatter or cracking occurs. It should be noted that the laser parameters need to be adaptively adjusted for different materials. For example, the laser power needs to be adjusted according to the material's absorptivity and the alloy's composition, and the external optical path configuration needs to be continuously adjusted to obtain welds that meet the application requirements.

[0086] Step S40, generating a corresponding control signal based on the welding stage and the laser parameter adjustment method;

[0087] In one embodiment, a corresponding control signal is generated according to the above laser parameter adjustment method and the preset welding stage. Specifically, the laser welding device is provided with corresponding control software, and by configuring parameters on the control software, the control software generates the corresponding control signal.

[0088] Step S50: welding the points to be welded based on the control signal to obtain a weld alloy after cooling and solidification.

[0089] In one embodiment, after the laser path and the points to be welded are set, the laser is turned on and the power of the laser is controlled according to a control signal, so that the laser welds each point to be welded according to a preset laser parameter adjustment method, and the welding of each welding point in the preset welding path is completed step by step to obtain a welded alloy after cooling and solidification.

[0090] Furthermore, in one embodiment, the step of aligning the laser beam with the point to be welded includes:

[0091] In step S21 , after the laser beam emitted by the laser passes through the collimator and is incident on the galvanometer, a preset welding point is drawn on the horizontal and vertical coordinates of the galvanometer based on a preset industrial control signal.

[0092] In one embodiment, an external optical path design of a 14um (micrometer) fiber core diameter laser + F120 collimator + galvanometer + F210 field mirror can be used. The external optical path design of small core diameter + large collimator + large field mirror makes the focused spot smaller, and can obtain higher power density and penetration performance. The purpose of selecting the galvanometer is fast speed. The time required for a single welding point is less than 0.2 seconds, the processing speed is fast, the efficiency is high, and it is conducive to the needs of industrial mass production.

[0093] Furthermore, in one embodiment, the laser is a QCW laser with a wavelength of 1070 nm and a pulse width of milliseconds.

[0094] The purpose of using this laser is to have good beam quality and M2 less than 1.2, which is conducive to breaking through the absorption threshold of the material and preventing high reflection phenomenon to obtain better welding quality.

[0095] Reference Figure 3 , Figure 3 This is a schematic diagram of the laser welding device in one embodiment of the laser welding method of the present invention; the device includes a power supply, a laser, a collimator, a galvanometer, a field mirror and a welding workbench (also known as the workbench in the figure).

[0096] In one example, the models of the devices are: laser model QCW-150W, collimator model COL-D30-F120, field lens model F210, and galvanometer model ATKG-AC-30.

[0097] Among them, the above-mentioned laser is used to connect to the power supply and emit laser to provide a heat source for welding; the above-mentioned collimator is used to collimate the laser light path, so that the divergent light path becomes a parallel light path; the above-mentioned field mirror is used to focus the laser emitted by the above-mentioned laser to improve the heating capacity of the laser light beam; the above-mentioned galvanometer is used to convert the received electrical signal of the industrial computer into a control program, and draw the preset welding point on the horizontal and vertical coordinates of the galvanometer. The shape, size and other parameters of the welding point can be set through the horizontal and vertical coordinates of the galvanometer; the above-mentioned welding workbench is used to provide a working position for laser welding materials, and the welding process requires pressing the first raw material to be welded and the second raw material to be welded on the welding workbench.

[0098] It should be noted that the external light path configuration used in the laser welding method of the present invention is not fixed and can be changed according to actual conditions to meet different needs.

[0099] This embodiment obtains the materials to be welded and places them on a welding workbench. After determining the welding points according to a preset welding path, laser parameters are adjusted in a preset number of welding stages to perform laser welding on the materials to produce a welded alloy. Adjusting laser process parameters enables high-quality laser welding of dissimilar and highly reflective materials without the addition of any welding medium, resulting in high processing efficiency and short processing time, meeting the requirements of industrial mass production.

[0100] Furthermore, based on the first embodiment of the laser welding method of the present invention, a second embodiment of the laser welding method of the present invention is proposed.

[0101] Reference Figure 4 , Figure 4 This is a detailed flow chart of step S30 in an embodiment of the laser welding method of the present invention. In a second embodiment, the step of dividing the laser welding process into a preset number of welding stages includes:

[0102] Step S31, setting the welding cycle, and setting the peak energy value, initial stable welding value, stable welding threshold and solidification threshold;

[0103] In one embodiment, a welding cycle is set, and a peak energy value, an initial stable welding value, a stable welding threshold, and a solidification threshold are set. The welding cycle is the period required to complete a weld, typically in the tens of milliseconds, and can be set based on the material being welded. The peak energy value is the high laser power value set to break through the material absorption threshold. The initial stable welding value refers to the laser power value when the material begins to melt and has a certain flowability. The stable welding threshold is the laser power value that allows the material to remain in a molten state. By reducing the laser power slightly from the initial stable welding value to the stable welding value, a stable molten pool is formed. Therefore, the initial stable welding value is lower than the initial stable welding value. The solidification threshold refers to the threshold at which the material to be welded has completed melting and begins to cool and solidify. Once the stable welding threshold is reached, the power (temperature) will fluctuate to cool the molten pool, and finally the power will be reduced to the solidification threshold. The peak energy value, initial stable welding value, stable welding threshold, and solidification threshold not only have corresponding power values, but also have time points, i.e., when the preset values ​​are reached.

[0104] Step S32, based on the peak energy value, the initial stable welding value, the stable welding threshold and the solidification threshold, the welding cycle is divided into four welding stages, and the laser parameter adjustment methods of the four welding stages are set respectively, and the corresponding time of each stage is the first preset time, the second preset time, the third preset time and the fourth preset time.

[0105] In one embodiment, the welding cycle is divided into four stages based on the peak energy value, the initial stable welding value, the stable welding threshold, and the solidification threshold. A first preset time is defined as the time from the start to the initial stable welding value; a second preset time is defined as the time from the initial stable welding value to the stable welding threshold; a third preset time is defined as the time from the stable welding value to the solidification threshold; and a fourth preset time is defined as the time from the solidification threshold to a power of zero. Furthermore, each interval is assigned a method for reaching each set value. For example, within the first preset time, the laser power must first be increased to the peak energy value and then decreased to the initial stable welding value; within the second preset time, the laser power must be decreased from the initial stable welding value to the stable welding threshold; within the third preset time, the laser power must be decreased from the stable welding threshold to the solidification threshold; and within the fourth preset time, the laser power must be decreased from the solidification threshold to zero.

[0106] Furthermore, in one embodiment, the step of generating a corresponding control signal based on the welding stage and the laser parameter adjustment method includes:

[0107] Step S41, dividing the welding cycle into a preset number of control points, each control point corresponding to a time point and a laser power;

[0108] In one embodiment, the welding cycle is divided into a preset number of control points, each corresponding to a time point and laser power. Specifically, 1ms is typically divided into 50 parts, or 50 control points, and the laser power is adjusted every 20μs. Assuming a welding cycle of 15ms, this corresponds to 750 control points. Of course, the preset number can be set based on the control program and process accuracy requirements.

[0109] Step S42, based on the peak energy value, the initial stable welding value, the stable welding threshold, the solidification threshold and the preset laser parameter adjustment method, select the control point to set the laser power of the four welding stages and generate corresponding control signals.

[0110] In one embodiment, control points are set based on the peak energy value, initial stable welding value, stable welding threshold, solidification threshold, and preset laser parameter adjustment method, and corresponding control signals are generated. For example, if a peak energy value of 1300W is required to be reached within 0.2ms, the power at the control point corresponding to 0.2ms is set to 1300W. In other words, the power is set to increase from an initial value at 0 to 1300W within 0.2ms. The setting of other values ​​can be referred to the above example and is not further described here. This embodiment achieves precise control of the weld waveform by dividing the welding cycle into a preset number of control points, meeting various control requirements.

[0111] Furthermore, in one embodiment, the step of welding the points to be welded based on the control signal to obtain a cooled and solidified welding alloy includes:

[0112] Step S51, turning on the laser, controlling the power of the laser to reach a peak energy value in a preset rapid increase manner within a first preset time, and then to reach an initial stable welding value in a preset rapid decrease manner after reaching the peak energy value;

[0113] Step S52, when the initial stable welding value is reached, controlling the power of the laser to decrease to the stable welding threshold in a preset slow-down manner within a second preset time;

[0114] Step S53, when the stable welding threshold is reached, controlling the power of the laser to decrease to the solidification threshold in a preset repeated rising and falling manner within a third preset time;

[0115] Step S54: When the solidification threshold is reached, the power of the laser is controlled to decrease slowly within a fourth preset time until the power is 0, thereby obtaining a cooled and solidified welding alloy.

[0116] Reference Figure 5 , Figure 5This is a schematic diagram of the welding point waveform in an embodiment of the laser welding method of the present invention. Figure 5 The waveform of the weld point in the figure is analyzed to illustrate the method of welding the weld point to be welded by adjusting the preset laser parameters in the present invention (the four stages of welding the silver-copper alloy and the tungsten-copper alloy in this embodiment are marked with 1, 2, 3, and 4, the horizontal axis is the laser welding time unit pulse width / ms, and the vertical axis is the laser power / W):

[0117] 1. First preset time: First, turn on the laser and quickly increase the power to 1200W peak energy. The purpose is to quickly break through the absorption threshold of copper, preparing the subsequent materials to better absorb the laser energy. After breaking through the absorption threshold of copper, that is, reaching the peak energy value, the copper's absorption rate increases, and the second stage does not require such high power, so the power is quickly reduced.

[0118] 2. Second preset time: The stable welding stage. As the temperature continues to rise, the energy setting waveform continues to decrease, starting from the initial stable welding value and falling to the stable welding threshold. The purpose is to increase the material's light absorption rate after the temperature rises, preventing the molten pool from reacting too violently and forming spatter and explosion points. Maintaining this temperature will ensure the formation of a better molten pool.

[0119] 3. The third preset time: After stabilizing the welding, a sawtooth wave is added, that is, the power of the laser is controlled to decrease to the solidification threshold in a preset repeated rise and fall manner. The purpose is to stir the molten pool and prevent impurities from exploding due to heat and forming explosion points.

[0120] 4. Fourth preset time: Slow down, which aims to slowly cool the molten pool and prevent the formation of pores. That is, after reaching the solidification threshold, the laser power is controlled to slowly decrease over the fourth preset time until the power reaches 0, resulting in a cooled and solidified weld alloy.

[0121] After testing, the laser welding method of the present invention was used to weld silver-copper alloy to tungsten-copper alloy, and the obtained welds had no yellowing or blackening, no spatter, and no explosion points. The molten pool was stable after welding, with no pores or collapse, and the single-point pull-out force tested after welding was greater than 50N.

[0122] This embodiment divides the welding process into four stages by setting a welding cycle, a peak energy value, an initial stable welding value, a stable welding threshold, and a solidification threshold. Different laser parameter adjustment methods are provided in each welding stage. The welding power is controlled through the four welding stages, thereby reducing defects such as explosion spots and pores caused by improper temperature control during the welding process, and obtaining high-quality welded parts made of dissimilar materials.

[0123] Furthermore, based on the previous embodiments of the laser welding method of the present invention, a third embodiment of the laser welding method of the present invention is proposed.

[0124] Reference Figure 6 , Figure 6 1 is a detailed flow chart of step S10 in an embodiment of the laser welding method of the present invention. In this embodiment, the steps of placing the material to be welded on a welding workbench, wherein the material to be welded is a first raw material to be welded and a second raw material to be welded of different materials, and pressing them together, include:

[0125] Step S11, selecting a silver-copper alloy of a first preset thickness as the first raw material to be welded among the materials to be welded, wherein the first preset thickness must meet a preset upper layer material thickness range;

[0126] Step S12, selecting a tungsten-copper alloy of a second preset thickness as the second raw material to be welded among the materials to be welded, wherein the second preset thickness must meet a preset lower layer material thickness range;

[0127] Step S13: Press the first raw material to be welded and the second raw material to be welded according to the standard of silver-copper alloy on top and tungsten-copper on the bottom, and then place them on the welding workbench.

[0128] In one embodiment, the materials to be welded are silver-copper alloy and tungsten-copper alloy. First, welding silver-copper alloy to tungsten-copper alloy is a dissimilar process, making it difficult to weld. Second, silver and copper are both highly reflective materials, requiring significant welding energy. Once the absorption threshold is exceeded, the material's absorption rate increases dramatically, leading to spattering, cracking, and difficulty in forming a stable molten pool, preventing an effective weld. Furthermore, the melting point of tungsten is three times higher than that of copper. At a wavelength of 1064nm, the absorption rate of tungsten-copper alloy is 47%, while that of copper is 4%. This significant difference in absorption rate during welding requires different welding energies. Given the absorption rate, if the same welding energy is used, copper will not yet have reached its melting point, while tungsten will have already reached its boiling point, resulting in numerous tiny cracks in the tungsten. These cracks can cause significant instability in the molten pool, resulting in spattering and cracking at the weld, preventing an effective weld. Therefore, typical dissimilar welding problems often arise when welding silver-copper and tungsten-copper alloys.

[0129] In one embodiment, in order to ensure the welding effect, it is necessary to limit the thickness of the material to be welded. Preferably, the thickness range of the upper material is set to 0.05-0.5mm, and the thickness range of the lower material is set to 0.5-3mm. The upper and lower layers are not classified, but the upper layer is thinner than the lower layer. Generally, when performing laser welding, the upper layer material is required to be thinner than the lower layer. If it exceeds this range, a higher power laser may be required to complete the welding. It should be noted that the material thickness range is related to the power of the laser, so the laser and the upper material thickness range and the lower material thickness range can be set according to actual conditions. Figure 7 , Figure 7This is a schematic diagram of material placement in an embodiment of the laser welding method of the present invention. The tungsten-copper alloy is placed on the lower layer, the silver-copper alloy is placed on the upper layer, and the two materials are placed together on a welding workbench.

[0130] It should be noted that the materials to be welded are not limited to silver-copper alloy and tungsten-copper alloy, and materials with thickness matching the laser power can be selected according to actual needs.

[0131] In this embodiment, a silver-copper alloy of a first preset thickness and a tungsten-copper alloy of a second preset thickness are selected. The first preset thickness and the second preset thickness must meet the preset upper and lower material thickness ranges, respectively. The first and second raw materials to be welded are placed on the welding table with the silver-copper alloy on top and the tungsten-copper on the bottom, awaiting welding. This embodiment ensures good welding results by rationally selecting the thickness of the materials to be welded and welding them in a stacked manner.

[0132] The present invention also provides a laser welding device. Figure 8 FIG. 1 is a schematic diagram of the functional modules of a laser welding device according to an embodiment of the present invention.

[0133] The laser welding device of the present invention comprises:

[0134] The sample placement module 10 is used to place the material to be welded on the welding workbench, wherein the material to be welded is obtained by laminating a first raw material to be welded and a second raw material to be welded, which are different in material;

[0135] A welding path module 20 is used to select a point to be welded on the material to be welded according to a preset welding path, and align the laser beam with the point to be welded;

[0136] A parameter setting module 30 is used to divide the laser welding process into a preset number of welding stages and set a preset laser parameter adjustment method for each welding stage;

[0137] The welding module 40 is configured to weld the points to be welded based on the control signal to obtain a welding alloy after cooling and solidification.

[0138] Optionally, the parameter setting module is further used to:

[0139] Set the welding cycle, and set the peak energy value, initial stable welding value, stable welding threshold and solidification threshold;

[0140] Based on the peak energy value, the initial stable welding value, the stable welding threshold and the solidification threshold, the welding cycle is divided into four welding stages, and the laser parameter adjustment methods of the four welding stages are set respectively, and the corresponding time of each stage is a first preset time, a second preset time, a third preset time and a fourth preset time.

[0141] Optionally, the parameter setting module is further used to:

[0142] Dividing the welding cycle into a preset number of control points, each control point corresponding to a time point and a laser power;

[0143] Based on the peak energy value, the initial stable welding value, the stable welding threshold, the solidification threshold and the preset laser parameter adjustment method, the control point is selected to set the laser power of the four welding stages and generate corresponding control signals.

[0144] Optionally, the welding module is further used to:

[0145] Turning on the laser, controlling the power of the laser to reach a peak energy value in a preset rapid increase manner within a first preset time, and then to reach an initial stable welding value in a preset rapid decrease manner after reaching the peak energy value;

[0146] After reaching the initial stable welding value, controlling the power of the laser to decrease to the stable welding threshold in a preset slow-down manner within a second preset time;

[0147] After reaching the stable welding threshold, controlling the power of the laser to decrease to the solidification threshold in a preset repeated rising and falling manner within a third preset time;

[0148] When the solidification threshold is reached, the power of the laser is controlled to slowly decrease within a fourth preset time until the power reaches 0, thereby obtaining a cooled and solidified welding alloy.

[0149] Optionally, the sample placement module is further used to:

[0150] Selecting a silver-copper alloy of a first preset thickness as the first raw material to be welded among the materials to be welded, wherein the first preset thickness must meet a preset upper material thickness range;

[0151] Selecting a tungsten-copper alloy of a second preset thickness as the second raw material to be welded in the materials to be welded, wherein the second preset thickness must meet a preset lower layer material thickness range;

[0152] The first raw material to be welded and the second raw material to be welded are pressed together according to the standard of silver-copper alloy on top and tungsten-copper on the bottom, and then placed on the welding workbench.

[0153] Optionally, the welding path module is further used to:

[0154] When the laser beam emitted by the laser passes through the collimator and is incident on the galvanometer, the preset welding point is drawn on the horizontal and vertical coordinates of the galvanometer based on the preset industrial control signal.

[0155] The present invention also provides a computer-readable storage medium.

[0156] The computer-readable storage medium of the present invention stores a laser welding program, and when the laser welding program is executed by a processor, the steps of the laser welding method described above are implemented.

[0157] The method implemented when the laser welding program running on the processor is executed can refer to the various embodiments of the laser welding method of the present invention, and will not be described in detail here.

[0158] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or system comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or system. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or system comprising the element.

[0159] The serial numbers of the above embodiments of the present invention are for description only and do not represent the advantages or disadvantages of the embodiments.

[0160] Through the description of the above embodiments, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus the necessary general hardware platform, and of course can also be implemented by hardware, but in many cases the former is a better embodiment. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes a number of instructions for enabling a terminal device (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods described in each embodiment of the present invention.

[0161] The above are only preferred embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A laser welding method, characterized in that: The laser welding method comprises the following steps: Placing a material to be welded on a welding workbench, wherein the material to be welded is obtained by laminating a first raw material to be welded and a second raw material to be welded, which are different in material; According to a preset welding path, a point to be welded is selected on the material to be welded, and a laser beam is aligned with the point to be welded; Dividing the laser welding process into a preset number of welding stages, and setting a preset laser parameter adjustment method for each welding stage; Based on the welding stage and the laser parameter adjustment method, generating a corresponding control signal; Based on the control signal, the power of the laser is controlled to reach a peak energy value in a preset rapid increase manner within a first preset time, and after reaching the peak energy value, the power of the laser is controlled to reach an initial stable welding value in a preset rapid decrease manner; After reaching the initial stable welding value, controlling the power of the laser to decrease to a stable welding threshold in a preset slow-down manner within a second preset time; After reaching the stable welding threshold, controlling the power of the laser to decrease to the solidification threshold in a preset repeated rising and falling manner within a third preset time; When the solidification threshold is reached, the power of the laser is controlled to slowly decrease within a fourth preset time until the power reaches 0, thereby obtaining a cooled and solidified welding alloy; The step of dividing the laser welding process into a preset number of welding stages includes: Set the welding cycle, and set the peak energy value, initial stable welding value, stable welding threshold and solidification threshold; Based on the peak energy value, the initial stable welding value, the stable welding threshold and the solidification threshold, the welding cycle is divided into four welding stages, and the laser parameter adjustment methods of the four welding stages are set respectively, and the corresponding time of each stage is a first preset time, a second preset time, a third preset time and a fourth preset time.

2. The laser welding method according to claim 1, wherein: The step of generating a corresponding control signal based on the welding stage and the laser parameter adjustment method includes: Dividing the welding cycle into a preset number of control points, each control point corresponding to a time point and a laser power; Based on the peak energy value, the initial stable welding value, the stable welding threshold, the solidification threshold and the preset laser parameter adjustment method, the control point is selected to set the laser power of the four welding stages and generate corresponding control signals.

3. The laser welding method according to claim 1, wherein: The step of placing the material to be welded on a welding workbench, wherein the material to be welded is a first raw material to be welded and a second raw material to be welded having different materials and pressed together, comprises: Selecting a silver-copper alloy of a first preset thickness as the first raw material to be welded among the materials to be welded, wherein the first preset thickness must meet a preset upper material thickness range; Selecting a tungsten-copper alloy of a second preset thickness as the second raw material to be welded in the materials to be welded, wherein the second preset thickness must meet a preset lower layer material thickness range; The first raw material to be welded and the second raw material to be welded are pressed together according to the standard of silver-copper alloy on top and tungsten-copper on the bottom, and then placed on the welding workbench.

4. The laser welding method according to claim 1, wherein: The step of aligning the laser beam with the point to be welded comprises: When the laser beam emitted by the laser passes through the collimator and is incident on the galvanometer, the preset welding point is drawn on the horizontal and vertical coordinates of the galvanometer based on the preset industrial control signal.

5. The laser welding method according to claim 1, wherein: The laser is a QCW laser with a wavelength of 1070 nm and a pulse width of milliseconds.

6. A laser welding device, characterized in that: The device comprises: A sample placement module is used to place the material to be welded on the welding workbench, wherein the material to be welded is obtained by pressing a first raw material to be welded and a second raw material to be welded of different materials; A welding path module, configured to select a point to be welded on the material to be welded according to a preset welding path, and align the laser beam with the point to be welded; a parameter setting module, configured to divide the laser welding process into a preset number of welding stages and to set a preset laser parameter adjustment mode for each welding stage, wherein the step of dividing the laser welding process into the preset number of welding stages comprises: setting a welding cycle, and setting a peak energy value, an initial stable welding value, a stable welding threshold, and a solidification threshold; dividing the welding cycle into four welding stages based on the peak energy value, the initial stable welding value, the stable welding threshold, and the solidification threshold, and setting laser parameter adjustment modes for the four welding stages respectively, with the time corresponding to each stage being a first preset time, a second preset time, a third preset time, and a fourth preset time; A control module, configured to generate corresponding control signals based on the welding stage and the laser parameter adjustment method; The welding module is used to control the power of the laser to reach a peak energy value in a preset rapid rising manner within a first preset time based on the control signal, and to reach an initial stable welding value in a preset rapid falling manner after reaching the peak energy value; after reaching the initial stable welding value, control the power of the laser to decrease to a stable welding threshold in a preset slow falling manner within a second preset time; after reaching the stable welding threshold, control the power of the laser to decrease to a solidification threshold in a preset repeated rising and falling manner within a third preset time; after reaching the solidification threshold, control the power of the laser to slowly decrease within a fourth preset time until the power is 0, thereby obtaining a welding alloy after cooling and solidification.

7. A laser welding device, characterized in that: The device includes: a memory, a processor, and a laser welding program stored in the memory and executable on the processor, wherein the laser welding program is configured to implement the steps of the laser welding method according to any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a laser welding program, which, when executed by a processor, implements the steps of the laser welding method according to any one of claims 1 to 5.

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