A welding component design device for dissimilar difficult-to-weld materials and a powder quantity proportioning requirement discrimination adaptive control method

Abstract

The application discloses a welding composition design device for dissimilar difficult-to-weld materials and a powder quantity proportioning requirement discrimination adaptive control method, which comprises a multiple-powder coaxial powder laying system, a superfast laser welding system, a powder quantity proportioning adaptive control system and a protective gas system.

Description

Technical Field

[0001] This invention belongs to the field of laser welding technology for dissimilar alloys, specifically relating to a welding composition design device and an adaptive control method for powder ratio determination for dissimilar and difficult-to-weld materials. Background Technology

[0002] With the optimization and upgrading of industrial structures, structural components made of single materials can no longer meet the needs of modern industrial development. Dissimilar metal composite structures have attracted much attention due to their advantages such as low cost, lightweight, and high performance. However, the thermophysical parameters of two dissimilar metals differ significantly, and a large number of brittle intermetallic compounds are easily formed at the interface, making it difficult to achieve high-quality connections using traditional welding methods. Therefore, how to achieve high-strength connections between dissimilar structures has become one of the challenges in promoting the application of dissimilar metal composite materials.

[0003] To address the above issues, CN 109570763 B, authorized in 2019, discloses a laser oscillation method and dissimilar metal welding equipment. This method uses an oscillating laser with a certain offset to achieve the connection of dissimilar metals, but it cannot connect two dissimilar metals with excessively large thermophysical parameters or those prone to forming brittle intermetallic compounds. CN113001024B, authorized in 2023, discloses a laser welding method for dissimilar materials, which uses a prefabricated intermediate layer to achieve a stable connection between dissimilar materials. However, limited by laser power, it is difficult to achieve efficient and high-quality connection of medium-thick plate dissimilar metal composite materials.

[0004] To address these issues, we propose a welding composition design device and an adaptive control method for powder ratio determination to prepare for dissimilar and difficult-to-weld materials. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a welding composition design device and an adaptive control method for determining the powder ratio requirements for dissimilar and difficult-to-weld materials.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] A welding composition design device and powder ratio requirement discrimination adaptive control method for dissimilar and difficult-to-weld materials include a multi-powder coaxial powder spreading system for conveying weld strengthening powder to the surface of the weldment, and controlling the start and stop of the corresponding powder feeding compression channel according to the weld gap and the actual powder feeding requirements.

[0008] Ultrafast laser welding system for joining weld strengthening powder with dissimilar, difficult-to-weld materials;

[0009] The powder ratio adaptive control system is used to realize real-time detection of the weld pool and adaptively control the multi-powder coaxial powder spreading system based on the welding conditions.

[0010] A shielding gas system is used to provide the shielding gas atmosphere required for welding.

[0011] and the workpiece.

[0012] Furthermore, the thickness of the workpiece ranges from 2.0mm to 8.0mm, and the materials of the left and right plates may be different. The workpiece can be made of steel, aluminum alloy, or titanium alloy.

[0013] Furthermore, the multi-powder coaxial spreading system includes a multi-powder coaxial spreading head, a powder mixer one, a powder mixer two, a powder mixer three, a powder mixer four, and a powder mixer five.

[0014] The multi-powder coaxial powder spreading head includes powder feeding and compression channel one, powder feeding and compression channel two, powder feeding and compression channel three, powder feeding and compression channel four, and powder feeding and compression channel five.

[0015] Each of the powder feeding and compression channels is connected to each of the powder mixers. Each of the powder feeding and compression channels extends to the tail end face of the multi-powder coaxial powder spreading system and communicates with the external environment to form a powder outlet. The tail width of the powder feeding and compression channel gradually narrows to convey the weld reinforcement powder mixed by the powder mixer. Each powder feeding and compression channel is located in the same plane.

[0016] Furthermore, the ultrafast laser welding system includes an ultrafast laser galvanometer and an ultrafast laser. The scanning mode of the ultrafast laser galvanometer is to oscillate back and forth perpendicular to the weld direction. The laser beam output by the ultrafast laser galvanometer is tilted to irradiate the area to be welded, and the included angle between the laser beam and the multi-powder coaxial powder spreading head is α.

[0017] Furthermore, the adjustment range of α is 10° to 60°.

[0018] Furthermore, the ultrafast laser galvanometer has a repetition frequency of not less than 20kHz, a laser power of not less than 8W, and a scanning speed of not less than 100mm / s.

[0019] Furthermore, the powder ratio adaptive control system includes an ultrafast laser welding monitoring device, a signal bus, and a multi-powder collaborative control system.

[0020] The ultrafast laser welding monitoring device is used to acquire the weld gap before welding and monitor the temperature field and molten pool morphology during the welding process. It can also scan the weld again after a single layer of welding is completed to confirm that no obvious forming defects appear in the single layer of weld. The multi-powder collaborative control system performs image processing on the relevant signals detected by the ultrafast laser welding monitoring device and determines the optimal process parameters and powder ratio based on the weld gap. If there are obvious defects in the current layer of weld, the defects are image-identified, and defect judgment and signal conversion are performed based on the defect characteristics to obtain the optimal repair welding parameters, powder ratio and total amount. The signal is transmitted to the multi-powder coaxial powder spreading system, ultrafast laser welding system and shielding gas system through the signal bus.

[0021] Furthermore, the protective gas system includes a protective gas pipe and a protective gas cylinder. The protective gas pipe is located behind the area to be welded for the workpiece. The angle between the protective gas pipe and the workpiece is β, and the adjustment range of β is 30° to 60°. The protective gas flow rate should be greater than 20 L / min. After the welding process is completed, the protective gas system is turned on to remove residual powder from the weld surface.

[0022] Another objective of this invention is to provide an adaptive control method for determining the powder ratio requirements of a welding composition design device for dissimilar and difficult-to-weld materials, comprising the following steps:

[0023] S1. Obtain the bevel shape, size and thickness of the workpiece to be welded, and solve for the optimal number of multi-powder coaxial powder laying welding layers, the initial powder feeding amount and powder ratio of each powder feeding and compression channel under different gaps, and the ultrafast laser welding process parameters.

[0024] S2. The above parameters are transmitted to the multi-powder coaxial powder spreading system, ultrafast laser welding system, and shielding gas system via the signal bus to start welding;

[0025] S3. After the single-layer welding is completed, the ultrafast laser welding monitoring device transmits the temperature field, molten pool morphology and weld gap information of the welding process to the multi-powder collaborative control system. If there is a large welding defect, the area will be repaired in a targeted manner.

[0026] S4. When the welding gap reaches a certain value, adjust the powder ratio in the powder feeder and start the other powder feeding channels to ensure a homogeneous transition of materials in the welding gap of dissimilar welding joints.

[0027] Furthermore, the powder content required for one side of the workpiece is a, and the powder content required for the other side of the workpiece is b. The powder feeding and compression channels from left to right are named A1, A2, A3, A4, and A5, respectively.

[0028] ④ If the weld gap size is 0-1mm, only channel A3 is used for powder feeding. The default powder ratio is a:b=1:1. Depending on the welding material, an appropriate amount of intermediate layer powder or weld strengthening powder is added.

[0029] ⑤ If the weld gap size is 1-3mm, use channels A2, A3, and A4 for powder feeding. The default powder ratio for channel A3 is a:b = 1:1. For channel A2, the powder ratio range for a is 60%-80% and for b is 20%-40%. For channel A4, the powder ratio range for a is 20%-40% and for b is 60%-80%.

[0030] If the weld gap is greater than 3mm, all powder feeding and compression channels will be activated. The default powder ratio for channel A3 is a:b = 1:1. For channel A1, the powder ratio range for a is 70%-100%, and for b is 0%-30%. For channel A2, the powder ratio range for a is 50%-80%, and for b is 20%-50%. For channel A4, the powder ratio range for a is 20%-50%, and for b is 50%-80%. For channel A5, the powder ratio range for a is 0%-30%, and for b is 70%-100%.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0032] This invention combines multiple powder feeding and compression channels into a single powder spreading port, and employs an adaptive powder ratio control system to adjust the welding process in real time based on the welding gap and the base materials on both sides, thereby improving the welding quality. Attached Figure Description

[0033] Figure 1 Overall diagram of the device for designing welding components for dissimilar and difficult-to-weld materials;

[0034] Figure 2 A schematic diagram of a multi-powder coaxial powder spreading head structure.

[0035] In the diagram: 1-Multi-powder coaxial spreading system; 10-Multi-powder coaxial spreading head; 11-Mixer 1; 12-Mixer 2; 13-Mixer 3; 14-Mixer 4; 15-Mixer 5;

[0036] 101 - Powder feeding compression channel 1; 102 - Powder feeding compression channel 2; 103 - Powder feeding compression channel 3; 104 - Powder feeding compression channel 4; 105 - Powder feeding compression channel 5;

[0037] 2-Ultrafast laser welding system; 21-Ultrafast laser galvanometer; 22-Ultrafast laser;

[0038] 3- Adaptive powder ratio control system; 31- Ultrafast laser welding monitoring system; 32- Signal bus; 33- Multi-powder collaborative control system;

[0039] 4-Protective gas system; 41-Protective gas tubing; 42-Protective gas cylinder;

[0040] 5-Workpiece;

[0041] 51 - Workpiece 1; 52 - Workpiece 2 Detailed Implementation

[0042] The following will describe in detail the implementation of this application with reference to the accompanying drawings and embodiments, so that the implementation process of how this application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0043] like Figure 1 As shown, a welding composition design device for dissimilar and difficult-to-weld materials includes a multi-powder coaxial powder spreading system 1, an ultrafast laser welding system 2, a powder ratio adaptive control system 3, a shielding gas system 4, and a workpiece 5.

[0044] The multi-powder coaxial powder spreading system 1 includes a multi-powder coaxial powder spreading head 10, a first powder mixer 11, a second powder mixer 12, a third powder mixer 13, a fourth powder mixer 14, and a fifth powder mixer 15. The multi-powder coaxial powder spreading head 10 includes a first powder feeding compression channel 101, a second powder feeding compression channel 102, a third powder feeding compression channel 103, a fourth powder feeding compression channel 104, and a fifth powder feeding compression channel 105. Each powder feeding compression channel is connected to the respective powder mixer. Each powder feeding compression channel extends to the tail end face of the multi-powder coaxial powder spreading system 1 and communicates with the external environment to form a powder outlet. The width of the tail end of the powder feeding compression channel gradually narrows to convey the weld strengthening powder mixed by the powder mixer. Each powder feeding compression channel is located in the same plane.

[0045] The ultrafast laser welding system 2 includes an ultrafast laser galvanometer 21 and an ultrafast laser 22;

[0046] Optionally, the ultrafast laser galvanometer 21 has a repetition frequency of not less than 20kHz, a laser power of not less than 8W, a scanning speed of not less than 100mm / s, and a scanning form of reciprocating oscillation perpendicular to the weld direction.

[0047] Optionally, the laser beam output by the ultrafast laser galvanometer 21 is tilted off-axis to irradiate the area to be welded, and the angle between it and the multi-powder coaxial powder spreading head 10 is α, and the adjustment range of α is 10° to 60°.

[0048] The powder ratio adaptive control system 3 includes an ultrafast laser welding monitoring device 31, a signal bus 32, and a multi-powder collaborative control system 33. The ultrafast laser welding monitoring device 31 is used to acquire the weld gap before welding and monitor the temperature field and molten pool morphology during the welding process. Furthermore, it can re-scan the weld after a single layer of welding to confirm that no obvious forming defects appear within the single layer. The multi-powder collaborative control system 33 performs image processing on the relevant signals detected by the ultrafast laser welding monitoring device 31 and determines the optimal process parameters and powder ratio based on the weld gap. If there are obvious defects in the current layer of weld, the defects are image-recognized, and defect judgment and signal conversion are performed based on the defect characteristics to obtain the optimal repair welding parameters, powder ratio, and total amount. The signals are transmitted to the multi-powder coaxial powder spreading system 1, the ultrafast laser welding system 2, the shielding gas system 4, and other equipment via the signal bus 32.

[0049] The protective gas system 4 includes a protective gas pipe 41 and a protective gas cylinder 42, wherein the protective gas pipe 41 is located behind the area to be welded.

[0050] Optionally, the included angle between the protective air pipe 41 and the workpiece 5 is β, the adjustment range of β is 30°~60°, and the protective air flow rate should be greater than 20L / min;

[0051] Optionally, after the welding process is completed, the shielding gas system 4 is turned on to remove residual powder from the weld surface;

[0052] Optionally, the thickness of workpiece 5 ranges from 2.0 mm to 8.0 mm;

[0053] Optionally, the materials of the left and right plates of the workpiece can be different, and the workpiece can be made of steel, aluminum alloy or titanium alloy.

[0054] Example 1:

[0055] This embodiment provides a method for determining and adaptively controlling the powder ratio requirements for dissimilar metal welding, including the following steps:

[0056] S1, obtain the bevel shape, size and thickness of the workpiece 5 to be welded, obtain the optimal number of multi-powder coaxial powder laying welding layers, the initial powder feeding amount and powder ratio of each powder feeding compression channel under different gaps, ultrafast laser welding process parameters, etc.

[0057] S2, the above parameters are transmitted to the multi-powder coaxial powder spreading system 1, ultrafast laser welding system 2, shielding gas system 4 and other equipment via signal bus 32, and welding begins;

[0058] S3. After the single-layer welding is completed, the ultrafast laser welding monitoring device 31 transmits information such as the temperature field of the welding process, the morphology of the molten pool and the weld gap after welding to the multi-powder collaborative control system 33. If there is a large welding defect, the area will be repaired in a targeted manner.

[0059] S4. When the welding gap reaches a certain value, adjust the powder ratio in the powder feeder and start the other powder feeding channels to ensure a homogeneous transition of materials in the welding gap of dissimilar welding joints.

[0060] Example 2:

[0061] This embodiment provides an adaptive control method for powder ratio in ultrafast laser welding process. The method is characterized by letting the powder content required for the workpiece on the left be a, and the powder content required for the workpiece on the right be b, and naming the powder feeding and compression channels from left to right as A1, A2, A3, A4, and A5, respectively.

[0062] Optionally, if the weld gap size is 0-1mm, only the A3 channel is used for powder feeding. The default powder ratio is a:b=1:1. Depending on the welding material, intermediate layer powder or weld strengthening powder may be added in appropriate amounts.

[0063] Optionally, if the weld gap size is 1-3mm, channels A2, A3, and A4 are used for powder feeding. The default powder ratio for channel A3 is a:b = 1:1. For channel A2, the powder ratio range for a is 60%-80%, and the powder ratio range for b is 20%-40%. For channel A4, the powder ratio range for a is 20%-40%, and the powder ratio range for b is 60%-80%.

[0064] Optionally, if the weld gap is greater than 3mm, all powder feeding and compression channels are enabled. The default powder ratio for channel A3 is a:b = 1:1. For channel A1, the powder ratio range for a is 70%-100%, and the powder ratio range for b is 0%-30%. For channel A2, the powder ratio range for a is 50%-80%, and the powder ratio range for b is 20%-50%. For channel A4, the powder ratio range for a is 20%-50%, and the powder ratio range for b is 50%-80%. For channel A5, the powder ratio range for a is 0%-30%, and the powder ratio range for b is 70%-100%.

[0065] Example 3:

[0066] This embodiment provides a weld strengthening powder suitable for laser welding of dissimilar metals, which adds nano-ceramic particles or trace strengthening elements based on the requirements of dissimilar welds.

[0067] Optionally, the shape of the nano-ceramic particles can be nanopowder, nanowire, nanotube, etc.

[0068] Optionally, trace fortifying elements include lithium, nickel, etc.

[0069] Optionally, the content of nano-ceramic particles and trace reinforcing elements shall not exceed 10% of the total powder material.

[0070] In summary, the above embodiments are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

[0071] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall fall within the scope of the technical solution of the present invention.

Claims

1. An adaptive control method for powder ratio determination in a welding composition design device for dissimilar and difficult-to-weld materials, the welding composition design device comprising: A multi-powder coaxial powder spreading system (1) is used to deliver weld strengthening powder to the surface of the weldment. According to the weld gap and the actual powder feeding requirements, the corresponding powder feeding compression channel is controlled to start and stop. The multi-powder coaxial powder spreading system (1) includes a multi-powder coaxial powder spreading head (10), a powder mixer one (11), a powder mixer two (12), a powder mixer three (13), a powder mixer four (14), and a powder mixer five (15). The multi-powder coaxial powder spreading head (10) includes a powder feeding compression channel one (101), a powder feeding compression channel two (102), a powder feeding compression channel three (103), a powder feeding compression channel four (104), and a powder feeding compression channel five (105). An ultrafast laser welding system (2) is used to achieve the connection between weld strengthening powder and dissimilar difficult-to-weld materials; The powder ratio adaptive control system (3) is used to realize real-time detection of welding and adaptively control the multi-powder coaxial powder spreading system (1) based on the welding situation. A shielding gas system (4) is used to provide the shielding gas atmosphere required for welding; and workpiece (5); The powder ratio adaptive control system (3) includes an ultrafast laser welding monitoring device (31), a signal bus (32), and a multi-powder collaborative control system (33), characterized by the following steps: S1. Obtain the bevel shape, size, and thickness of the workpiece (5) to be welded, and solve for the optimal number of multi-powder coaxial powder-laying welding layers, the initial powder feeding amount and powder ratio of each powder feeding compression channel under different gaps, and the ultrafast laser welding process parameters. Let the powder content required for one side of the workpiece be a, and the powder content required for the other side of the workpiece be b. The powder feeding and compression channels from left to right are named A1, A2, A3, A4, and A5, respectively. ① If the weld gap size is less than 1mm, only channel A3 is used for powder feeding. The default powder ratio is a:b=1:

1. Depending on the welding material, an appropriate amount of intermediate layer powder or weld strengthening powder is added. ② If the weld gap size is 1-3mm, use channels A2, A3, and A4 for powder feeding. The default powder ratio for channel A3 is a:b = 1:

1. For channel A2, the powder ratio range for a is 60%-80% and for b is 20%-40%. For channel A4, the powder ratio range for a is 20%-40% and for b is 60%-80%. ③ If the weld gap is greater than 3mm, all powder feeding and compression channels will be activated. The default powder ratio for channel A3 is a:b = 1:

1. For channel A1, the powder ratio range for a is 70%-100%, and the powder ratio range for b is 0%-30%. For channel A2, the powder ratio range for a is 50%-80%, and the powder ratio range for b is 20%-50%. For channel A4, the powder ratio range for a is 20%-50%, and the powder ratio range for b is 50%-80%. For channel A5, the powder ratio range for a is 0%-30%, and the powder ratio range for b is 70%-100%. S2. The above parameters are transmitted to the multi-powder coaxial powder spreading system (1), ultrafast laser welding system (2), and shielding gas system (4) via the signal bus (32) to start welding; S3. After the single-layer welding is completed, the ultrafast laser welding monitoring device (31) transmits the temperature field, molten pool morphology and weld gap information of the welding process to the multi-powder collaborative control system (33). If there is a region with welding size defects, then the region is repaired at specific points. S4. When the welding gap reaches a certain value, adjust the powder ratio in the powder feeder and start the other powder feeding channels to ensure a homogeneous transition of materials in the welding gap of dissimilar welding joints.

2. The powder ratio determination and adaptive control method for the welding composition design device for dissimilar and difficult-to-weld materials according to claim 1, characterized in that, Each of the powder feeding and compression channels is connected to each of the powder mixers. Each of the powder feeding and compression channels extends to the tail end face of the multi-powder coaxial powder spreading system (1) and communicates with the external environment to form a powder outlet. The tail width of the powder feeding and compression channel gradually narrows to convey the weld reinforcement powder mixed by the powder mixer. Each powder feeding and compression channel is located in the same plane.

3. The powder ratio determination and adaptive control method for the welding composition design device for dissimilar and difficult-to-weld materials according to claim 1, characterized in that: The ultrafast laser welding system (2) includes an ultrafast laser galvanometer (21) and an ultrafast laser (22). The scanning mode of the ultrafast laser galvanometer (21) is to oscillate back and forth perpendicular to the weld direction. The laser beam output by the ultrafast laser galvanometer (21) is tilted to irradiate the area to be welded, and the angle between it and the multi-powder coaxial powder spreading head (10) is α.

4. The powder ratio determination and adaptive control method for the welding composition design device for dissimilar and difficult-to-weld materials according to claim 3, characterized in that: The adjustment range of α is 10° to 60°.

5. The powder ratio determination and adaptive control method for the welding composition design device for dissimilar and difficult-to-weld materials according to claim 1, characterized in that: The powder ratio adaptive control system (3) includes an ultrafast laser welding monitoring device (31), a signal bus (32), and a multi-powder collaborative control system (33). The ultrafast laser welding monitoring device (31) is used to obtain the weld gap before welding and monitor the temperature field and molten pool morphology during the welding process. At the same time, it can scan the weld again after the single-layer welding is completed to confirm that no obvious forming defects appear in the single-layer weld. The multi-powder collaborative control system (33) performs image processing on the relevant signals detected by the ultrafast laser welding monitoring device (31) and determines the optimal process parameters and powder ratio based on the weld gap. If there are obvious defects in the current layer weld, the defects are image-identified, and defect judgment and signal conversion are performed based on the defect characteristics to obtain the optimal repair welding parameters, powder ratio and total amount. The signal is transmitted to the multi-powder coaxial powder spreading system (1), ultrafast laser welding system (2) and shielding gas system (4) through the signal bus (32).

6. The powder ratio determination and adaptive control method for the welding composition design device for dissimilar and difficult-to-weld materials according to claim 1, characterized in that: The protective gas system (4) includes a protective gas pipe (41) and a protective gas cylinder (42). The protective gas pipe (41) is located behind the area to be welded for welding the workpiece (5). The angle between the protective gas pipe (41) and the workpiece (5) is β. The adjustment range of β is 30° to 60°. The protective gas flow rate should be greater than 20 L / min. After the welding process is completed, the protective gas system (4) is turned on to remove residual powder on the weld surface.

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