An Aluminum Alloy Laser Welding Defect Targeted Regulation Device and Method

Abstract

This patent discloses a device and method for targeted regulation of defects in laser welding of aluminum alloys. The device mainly includes a motion system, protective gas, laser welding device, control system, and laser. By using a ball mill to mix trace elements and magnetic particles, a targeted element is formed, and the targeted element is added to the aluminum alloy welding wire. Based on the defect monitoring data of the real-time monitoring platform, the control system is controlled to precisely control the position and intensity of the magnet in real time, and the element is targeted and transported to the defect position. The method mainly includes six steps: preparation of targeted element compensated welding wire, precise movement and positioning of the laser welding device, transportation of the welding wire containing magnetic particles to the welding area, real-time monitoring of the fluctuations of the welding molten pool and keyhole, analysis of the monitoring data to adjust the position and intensity of the magnet, and adjustment of the laser welding parameters, wire feeding speed, and magnet control strategy according to the real-time monitoring data and prediction results. This method can effectively reduce the generation of welding defects and improve the quality and strength of the welded joint.

Description

Technical Field

[0001] The present invention relates to the field of welding defect control, and particularly to a device and method for targeted control of laser welding defects in aluminum alloys. Background Art

[0002] Due to its characteristics such as light weight, good corrosion resistance, and good electrical conductivity, aluminum alloy is widely used in fields such as aviation, automobiles, and ships. As an efficient and low-damage welding method, laser welding has gradually been applied to the welding of aluminum alloys. However, during the laser welding process, it is difficult to avoid the generation of welding defects such as element burning loss, pores, cracks, etc. These defects will affect the quality and strength of the welded joint, and even lead to the failure of the welded part. Therefore, how to control the laser welding defects of aluminum alloys and improve the quality and strength of the welded joint has become an important research direction in the current laser welding of aluminum alloys.

[0003] Currently, the existing welding defect control methods mainly involve process parameter optimization, trace element control, and introduction of external field energy. However, these methods still face some limitations, such as unstable control effects, poor defect suppression effects, and the need to improve the accuracy of defect prediction. Among them, in terms of trace element control, its main goal is to improve the quality and performance of the entire weld area by adding or adjusting specific alloy elements. However, since different weld areas may have different types of defects, specific trace element addition strategies or a combination of multiple trace elements need to be adopted. To overcome the above problems, the present invention aims to provide a new device and method for targeted control of laser welding defects in aluminum alloys to improve welding quality and reduce the probability of defect generation. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the present invention provides a device and method for targeted control of laser welding defects in aluminum alloys. The device mainly includes a motion system, protective gas, a laser, a laser welding head, a wire feeding device, a pulsed magnetic field generator, a magnet, a high-speed camera, an X-ray detector, and a control system. The method mainly includes six steps: preparation of a targeted element compensation welding wire, precise movement and positioning of the laser welding device, feeding the welding wire containing magnetic particles to the welding area, real-time monitoring of the fluctuations of the welding molten pool and keyhole, analyzing the monitoring data based on an artificial neural network and adjusting the position and strength of the magnet, and adjusting the laser welding parameters, wire feeding speed, and magnet control strategy according to the real-time monitoring data and prediction results. By precisely controlling the welding process and targeting the delivery of targeted elements, the generation of welding defects is effectively reduced, and the quality and strength of the welded joint are improved. In addition, this method can further reduce the probability of defect occurrence by adjusting the welding parameters and magnet control strategy.

[0005] To achieve the above object, the present invention is implemented through the following technical solutions.

[0006] A device for targeted regulation of laser welding defects in aluminum alloy, characterized in that it mainly includes a motion system, protective gas, a laser welding device, a control system and a laser; the laser welding device is a box-shaped structure, and a laser welding tooling fixture is arranged inside. Guide rails that can move up and down are installed on the four sides of the device, and two slidable snap-type sliders are installed on each guide rail, which are convenient for moving and disassembling on the guide rail. Magnets are installed above the sliders, and the magnets are connected to a pulsed magnetic field generator. A wire filling device, a high-speed camera and an X-ray detector are installed on the laser welding head. The high-speed camera and the X-ray detector feed the detection data back to the computer of the control system. The welding wire conveyed in the wire filling device contains magnetic particles. The selected trace elements and magnetic particles are ball-milled by a ball mill, and the magnetic particles adhere to the surface of the trace elements to form a targeted element. Magnetic ceramic particles are nanomaterials composed of magnetic elements (such as iron, nickel, cobalt, chromium, manganese) and their compounds, such as Fe3O4, Fe3O4@SiO2, etc. The magnetic particles can accurately reach the frequently defective areas under the control of the magnets.

[0007] Furthermore, based on the constraint of the demand for targeted regulation of laser welding defects, a design strategy for the composition of light alloy welding wires is generated using a high-throughput calculation method. Based on the data in the knowledge base, the weights, thresholds, and the number of neurons of the model are efficiently trained with machine learning. Taking the defect type as the input, the content and scale of trace elements are output by using an artificial neural network, and a design space for the composition of light alloys is generated. First, an aluminum alloy welding wire ingot containing the targeted element is prepared by a high-temperature synthesis method, and then it is made into a welding wire with a diameter of 1.2 mm through multi-pass rolling and drawing processes. After the welding wire is straightened by a wire straightener, a welding test is carried out.

[0008] Furthermore, the defect types can be element burning loss, pores, cracks, etc. The magnetic particles attached to the surface of the trace elements can move freely under the action of the magnetic field. By controlling the position and intensity of the magnets, the targeted element can be transported to the frequently defective positions. For the element burning loss of aluminum alloy, the selected trace elements can be low-boiling-point elements such as Mg, Li, and Cu; for the hydrogen pore defect that is likely to occur during the laser welding process of aluminum alloy, the selected trace element can be the hydrogen-evolving element Nb; for the crack defect that is likely to occur during the laser welding process of aluminum alloy, the selected trace element can be ceramic particles. For a single defect, one trace element can be selected and combined with magnetic particles to generate a targeted element. The control system can adjust the position and intensity of the magnets in real time, and the targeted element can be transported to the high-defect area; or for the three defects, by adjusting the composition ratio of different trace elements and magnetic particles, as well as the position and intensity of the magnets, precise regulation of the element distribution, pores and cracks in different areas of the weld can be achieved.

[0009] Furthermore, high-speed cameras can monitor the fluctuations of the laser welding molten pool in real time, and X-ray detectors can monitor the fluctuations of the keyhole during the laser welding process. The control system analyzes the monitoring data in real time based on an artificial neural network and predicts the locations where defects frequently occur, and then adjusts the position and intensity of the magnet in real time.

[0010] A method for targeted regulation of laser welding defects in aluminum alloy can be realized through the following steps:

[0011] Step 1: Mix trace elements and magnetic particles using a ball mill to form targeted elements; add the prepared targeted elements to the aluminum alloy welding wire, and prepare an aluminum alloy welding wire ingot containing targeted elements through a high-temperature synthesis method; subject the aluminum alloy welding wire ingot to multiple passes of rolling and drawing processes to make a welding wire with a diameter of 1.2 mm.

[0012] Step 2: The laser welding device makes precise movements and positioning through the motion system to ensure the accuracy of the welding process; the shielding gas protects the welding area during welding to prevent oxidation and contamination; the laser emits a high-energy laser beam, which is focused on the welding workpiece through the laser welding head to achieve welding.

[0013] Step 3: Start the laser welding device and the wire feeding device, and transport the welding wire containing magnetic particles to the welding area; the pulsed magnetic field generator is connected to the magnet to generate a pulsed magnetic field during welding; during welding, high-speed cameras and X-ray detectors monitor the fluctuations of the welding molten pool and the keyhole in real time, and feed the detection data back to the control system.

[0014] Step 4: The control system analyzes the monitoring data based on an artificial neural network, predicts the locations where defects frequently occur, and according to the prediction results, during welding, for a single defect, the targeted elements can be transported to the high-defect area by controlling the position and intensity of the magnet. For multiple defects, precise regulation of element distribution, pores, and cracks in different regions of the weld can be achieved by adjusting the composition ratios of different trace elements and magnetic particles, as well as the position and intensity of the magnet.

[0015] Step 5: During welding, continuously adjust the laser welding parameters, wire feeding speed, and the control strategy of the magnet according to the real-time monitoring data and prediction results to achieve effective regulation of defects.

[0016] Step 6: After welding, use high-speed cameras and X-ray detectors to detect the welded joint and evaluate the welding quality; if there are quality problems, the welding parameters and the control strategy of the magnet can be adjusted according to the detection results, and welding can be carried out again.

[0017] Furthermore, during the welding process, the effective cooperation of the shielding gas and the laser welding device can reduce the generation of defects such as pores and cracks. At the same time, by adjusting the power of the laser and the welding speed, the molten pool fluctuation can be controlled to further reduce the probability of defect occurrence.

[0018] The advantages and positive effects of the present invention are as follows:

[0019] An aluminum alloy laser welding defect targeted regulation device and method of the present invention can achieve the precise delivery of targeted elements by precisely controlling the magnetic field position and energy during the welding process, thereby effectively reducing the occurrence of welding defects and improving the quality and strength of the welded joint. At the same time, by real-time monitoring the welding process and timely adjusting the laser welding parameters, wire feeding speed and magnet control strategy, the possibility of defect generation is further reduced. This invention provides a new technical approach for the field of aluminum alloy laser welding in China, helps to improve the welding quality, reduce the generation of defects, and has broad application potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic diagram of an aluminum alloy laser welding defect targeted regulation device.

[0021] Figure 2 is a schematic diagram of the preparation of targeted elements.

[0022] Figure 3 is a schematic diagram of an aluminum alloy laser welding defect targeted regulation method.

[0023] Figure 4 is a flow chart of an aluminum alloy laser welding defect targeted regulation method.

[0024] 1 - Motion system; 2 - Shielding gas; 4 - Control system; 5 - Laser; 6 - Trace elements; 7 - Magnetic particles; 8 - Ball mill; 9 - Targeted elements; 10 - Pore defect;

[0025] 3 - Laser welding device: 31 - Laser welding head; 32 - High-speed camera; 33 - Wire filling device; 34 - Slide block; 35 - Magnet; 36 - Guide rail; 37 - Tooling fixture; 38 - X-ray detector. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] For the convenience of those skilled in the art, the present invention will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. In addition, it should be noted that for the convenience of description, only the parts related to the present invention rather than all the structures are shown in the drawings.

[0027] The present invention will be further illustrated by a specific embodiment below.

[0028] Embodiment

[0029] As Figure 1 shown. This example is an apparatus and method for targeted regulation of laser welding defects in aluminum alloy, and is used to regulate the laser welding defects of 2060 aluminum-lithium alloy. During the laser welding process of aluminum-lithium alloy, element burn-off, pores and crack defects are likely to occur.

[0030] The present invention discloses an apparatus for targeted regulation of laser welding defects in aluminum alloy, which mainly includes a motion system 1, a protective gas 2, a laser welding device 3, a control system 4 and a laser 5.

[0031] The laser welding device 3 is of a box-shaped structure, and a laser welding tooling fixture 37 is arranged inside; guide rails 36 that can move up and down are installed on four sides of the device, and two slidable snap-type sliders 34 are installed on each guide rail, which is convenient for moving and disassembling on the guide rail; a magnet 35 is installed above the slider 34, and the magnet 35 is connected to a pulsed magnetic field generator; a wire filling device 33, a high-speed camera 32 and an X-ray detector 38 are installed on the laser welding head 31; the high-speed camera 32 and the X-ray detector 38 feed the detection data back to the computer of the control system 4;

[0032] The welding wire conveyed in the laser wire filling device 33 contains magnetic particles 7. The selected trace elements 6 and magnetic particles 7 are ball-milled by a ball mill 8, and the magnetic particles 7 adhere to the surface of the trace elements 6 to form targeted elements 9;

[0033] The magnetic ceramic particles are nanomaterials composed of magnetic elements (such as iron, nickel, cobalt, chromium, manganese) and their compounds, such as Fe3O4, Fe3O4@SiO2, etc.; the selected trace elements (6) can be Mg, Li, Nb trace elements and TiC particles. Among them, the addition of low-boiling-point elements Mg and Li can compensate for the element burn-off in the area close to the laser spot during the laser welding of aluminum-lithium alloy; the addition of Nb element can reduce the pore defects in the keyhole area of the laser welding of aluminum-lithium alloy; the implantation of TiC ceramic particles can inhibit the crack defects at the edge of the fusion line during the laser welding of aluminum-lithium alloy. The magnetic particles can accurately reach the defect-prone area under the control of the magnet 35.

[0034] Constrained by the requirements of targeted regulation of laser welding defects, a light alloy welding wire composition design strategy is generated using a high-throughput calculation method. Based on the data in the knowledge base, the weights, thresholds, and the number of neurons of the model are efficiently trained and machine-learned. Taking the defect types as the input, the content and scale of trace elements are output by using an artificial neural network, and a light alloy composition design space is generated.

[0035] First, an aluminum alloy welding wire ingot containing the target element 9 is prepared by the high-temperature synthesis method, and then it is made into a welding wire with a diameter of 1.2 mm through multi-pass rolling and drawing processes. After the welding wire is straightened by a wire straightener, a welding test is carried out. The types of defects can be element burning loss, pores, cracks, etc. The magnetic particles 7 attached to the surface of the trace element 6 can move freely under the action of a magnetic field, and the target element 9 can be transported to the positions where defects frequently occur by controlling the position and intensity of the magnet.

[0036] The high-speed camera 32 can monitor the fluctuation of the laser welding molten pool in real time, and the X-ray detector 38 can monitor the fluctuation of the keyhole during the laser welding process in real time. The control system analyzes the monitoring data in real time based on an artificial neural network and predicts the positions where defects frequently occur, and then adjusts the position and intensity of the magnet in real time.

[0037] A method for targeted regulation of laser welding defects in 2060 aluminum-lithium alloy can be realized through the following steps:

[0038] Step 1: Use a ball mill to mix trace elements Mg, Li, Nb, trace element TiC particles, and magnetic particles Fe3O4@SiO2 to form a target element. Among them, the Mg and Li elements are mixed with 20% Fe3O4@SiO2 particles, the Nb element is mixed with 60% Fe3O4@SiO2 particles, and the TiC particles are mixed with 100% Fe3O4@SiO2 particles. Add the prepared target element to the aluminum alloy welding wire, and the welding wire composition is Al-5.80 Cu-1.20 Li-0.20 Mn-0.10 V-0.20 Zr-0.20 Si-0.30 Fe-0.20Mg-1.20 Nb-Fe3O4@SiO2. Prepare an aluminum alloy welding wire ingot containing the target element by the high-temperature synthesis method. The key to this step is to control the content and distribution of the target element to ensure the welding quality. Pass the prepared aluminum alloy welding wire containing the target element through multi-pass rolling and drawing processes to make a welding wire with a diameter of 1.2 mm.

[0039] Step 2: The laser welding device makes precise movement and positioning through the motion system to ensure the accuracy of the welding process; the shielding gas protects the welding area during the welding process to prevent oxidation and contamination; the laser emits a high-energy laser beam, which is focused on the welding workpiece through the laser welding head to achieve welding.

[0040] Step 3: Start the laser welding device and the wire feeding device, and feed the welding wire containing magnetic particles to the welding area. The welding power is 2200W, the welding speed is 30mm / s, and the wire feeding speed is 45mm / s. The pulsed magnetic field generator is connected to the magnet to generate a pulsed magnetic field during welding. The magnetic field waveform has a peak value of 5T, a full pulse width of 1000ms, and a flat top time of 100ms. During welding, a high-speed camera and an X-ray detector are used to monitor the fluctuations of the welding molten pool and the keyhole in real time, and the detection data is fed back to the control system.

[0041] Step 4: The control system analyzes the monitoring data based on an artificial neural network to predict the positions where defects frequently occur. According to the prediction results, the control system adjusts the position and intensity of the magnet to accurately deliver the target elements to the areas where defects frequently occur.

[0042] Step 5: During welding, continuously adjust the laser welding parameters, wire feeding speed, and control strategy of the magnet according to the real-time monitoring data and prediction results to achieve effective control of defects.

[0043] Step 6: After welding, use a high-speed camera and an X-ray detector to detect the welded joint and evaluate the welding quality. If there are quality problems, the welding parameters and the control strategy of the magnet can be adjusted according to the detection results, and welding can be carried out again.

[0044] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limiting the implementation manners of the present invention. For those of ordinary skill in the art, based on the idea of the present invention, there will be changes in the specific implementation manners and application scopes. The content of this specification should not be construed as a limitation to the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the claims of the present invention.

Claims

1. A device for targeted regulation of laser welding defects in aluminum alloy, characterized in that: It mainly includes a motion system (1), a shielding gas (2), a laser welding device (3), a control system (4), and a laser (5); The laser welding device (3) is of a box structure with a tooling fixture (37) arranged inside; on four sides of the device, vertically movable guide rails (36) are installed, and two slidable snap-type sliders (34) are installed on each guide rail, facilitating movement and disassembly on the guide rails; a magnet (35) is installed above the slider (34), and the magnet (35) is connected to a pulsed magnetic field generator; a wire filling device (33), a high-speed camera (32), and an X-ray detector (38) are installed on the laser welding head (31); the high-speed camera (32) and the X-ray detector (38) feed the detected data back to the computer of the control system (4); The high-speed camera (32) can monitor the fluctuations of the laser welding molten pool in real time, and the X-ray detector (38) can monitor the fluctuations of the keyhole during the laser welding process in real time. The control system analyzes the monitored data in real time based on an artificial neural network and predicts the positions where defects frequently occur. According to the prediction results, the position and intensity of the magnet are adjusted in real time to transport the targeted element to the areas with high defect occurrence; The welding wire conveyed by the wire filling device (33) contains magnetic particles (7). The selected trace element (6) and the magnetic particles (7) are ball-milled by a ball mill (8), and the magnetic particles (7) adhere to the surface of the trace element (6) to form a targeted element (9); The magnetic particles are nanomaterials composed of magnetic elements and their compounds, and the magnetic particles can accurately reach the areas with high defect occurrence under the control of the magnet (35); Constrained by the requirements of targeted regulation of laser welding defects, a light alloy welding wire composition design strategy is generated using a high-throughput calculation method. Based on the data in the knowledge base, the weights, thresholds, and the number of neurons of the model are efficiently trained and machine-learned. Taking the defect types as input values, the content and scale of the trace elements are output by using an artificial neural network, and a light alloy composition design space is generated; For the burning loss of aluminum alloy elements, the selected trace element (6) is low-boiling-point elements such as Mg and Li; for the hydrogen pore defect that easily appears during the laser welding of aluminum alloy, the selected trace element (6) is the Nb element; for the crack defect that easily appears during the laser welding of aluminum alloy, the selected trace element (6) is ceramic particles; For a single defect, one trace element (6) is combined with the magnetic particles (7) to generate a targeted element (9). The control system adjusts the position and intensity of the magnet in real time to transport the targeted element (9) to the areas with high defect occurrence; for the three defects, by adjusting the composition ratios of different trace elements (6) and the magnetic particles (7), as well as the position and intensity of the magnet, precise regulation of the element distribution, pores, and cracks in different regions of the weld seam is achieved.

2. The aluminum alloy laser welding defect targeted regulation device according to claim 1, wherein: The method for preparing the welding wire is as follows: First, an aluminum alloy welding wire ingot containing the targeted element (9) is prepared by a high-temperature synthesis method, and then it is made into a welding wire with a diameter of 1.2 mm through multi-pass rolling and drawing processes. After the welding wire is straightened by a wire straightener, it is welded.

3. The regulation method of an aluminum alloy laser welding defect targeting regulation device according to claim 1, characterized in that, The method includes the following steps: Step 1: using a ball mill (8) to mix trace elements (6) and magnetic particles (7) to form a targeting element (9); adding the prepared targeting element (9) to an aluminum alloy welding wire, and preparing an aluminum alloy welding wire ingot containing the targeting element by a high-temperature synthesis method; subjecting the aluminum alloy welding wire ingot to a multi-pass rolling and drawing process to prepare a welding wire with a diameter of 1.2 mm; Step 2: The laser welding device (3) is precisely moved and positioned through the motion system (1) to ensure the accuracy of the welding process; the protective gas (2) protects the welding area during the welding process to prevent oxidation and contamination; the laser (5) emits a high-energy laser beam, which is focused on the welding workpiece through the laser welding head (31) to achieve welding; Step 3: Start the laser welding device (3) and the wire filling device (33) to deliver the welding wire containing magnetic particles (7) to the welding area; connect the pulse magnetic field generator to the magnet (35) to generate a pulse magnetic field during the welding process; during the welding process, the high-speed camera (32) and the X-ray detector (38) monitor the fluctuation of the welding pool and the keyhole in real time, and feed back the detection data to the control system (4); Step 4: The control system (4) analyzes the monitoring data based on an artificial neural network to predict the locations where defects frequently occur. Based on the prediction results, during the welding process, for a single defect, the position and strength of the magnet are controlled to transport the targeted element to the defect-prone area. For multiple defects, the distribution of elements, pores and cracks in different areas of the weld are precisely controlled by adjusting the composition ratio of different trace elements to magnetic particles, the position and strength of the magnet. Step 5: During the welding process, according to the real-time monitoring data and the prediction results, the control strategy of the laser welding parameters, the wire feeding speed and the magnet (35) is continuously adjusted to achieve effective control of the defects; Step 6: After welding is completed, the welded joint is inspected by a high-speed camera (32) and an X-ray detector (38) to evaluate the welding quality; if there is a quality problem, the welding parameters and the control strategy of the magnet (35) can be adjusted according to the inspection results, and the welding can be repeated.

4. The regulation method according to claim 3, characterized in that: During the welding process, the generation of defects such as pores and cracks is reduced through the effective coordination of the protective gas (2) and the laser welding device (3); at the same time, the fluctuation of the molten pool is controlled by adjusting the power and welding speed of the laser (5), thereby further reducing the probability of defect occurrence.

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