Vacuum laser welding method for aluminum alloy with complex structure

Abstract

The invention discloses a vacuum laser welding method for aluminum alloy with a complex structure, which belongs to the technical field of vacuum laser welding and comprises the following steps: mounting an aluminum alloy to-be-welded part on a three-jaw chuck, and presetting an arc starting plate and an arc stopping plate at two ends of a to-be-welded welding seam to obtain a to-be-welded assembly; setting aluminum alloy vacuum laser welding parameters; and the to-be-welded assembly is put into the vacuum cabin, and laser welding is conducted according to the aluminum alloy vacuum laser welding parameters. The method improves the quality of the industrial production aluminum alloy vacuum laser welding seam and improves the production efficiency.

Description

Technical Field

[0001] This invention belongs to the field of vacuum laser welding technology, and particularly relates to a vacuum laser welding method for complex aluminum alloy structures. Background Technology

[0002] In a vacuum environment, the boiling point of materials decreases, energy utilization increases, and the vacuum environment significantly suppresses laser plume. The resulting weld depth is approximately 2.5 times that of atmospheric laser welding, while the required vacuum level is only 10–10⁻⁶. 3 Compared with electron beam welding, Pa has a large aspect ratio molten pool morphology and a wider range of vacuum requirements, making it extremely economical and practical.

[0003] In actual industrial production, differences in weld assembly conditions, complex weld structures, and varying thicknesses can lead to more welding defects. Summary of the Invention

[0004] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a vacuum laser welding method for complex aluminum alloy structures, which improves the quality of vacuum laser welds in industrial production of aluminum alloys and increases production efficiency.

[0005] The objective of this invention is achieved through the following technical solution: a method for vacuum laser welding of aluminum alloys with complex structures, comprising: mounting the aluminum alloy workpiece to be welded on a three-jaw chuck, pre-positioning an arc-starting plate and an arc-ending plate at both ends of the weld seam to be welded, thereby obtaining the assembly to be welded; setting the vacuum laser welding parameters for the aluminum alloy; placing the assembly to be welded into a vacuum chamber, and performing laser welding according to the vacuum laser welding parameters for the aluminum alloy.

[0006] In the above-mentioned vacuum laser welding method for complex aluminum alloy structures, the vacuum laser welding parameters for aluminum alloys include laser power, welding speed, defocusing amount, weld arc initiation distance, weld arc termination distance, laser head deflection angle, argon gas flow rate, and weld butt thickness.

[0007] In the above-mentioned vacuum laser welding method for complex aluminum alloy structures, the weld thickness is 4 mm to 15 mm, the weld gap is ≤0.2 mm, and the weld step difference is ≤0.3 mm.

[0008] In the above-mentioned vacuum laser welding method for complex aluminum alloy structures, the laser power is 3000 W to 9000 W, the welding speed is 10 mm / s to 40 mm / s, the defocusing amount is -15 mm to +15 mm, the arc starting distance of the weld is ≥5 mm, the arc ending distance of the weld is ≥15 mm, the laser head deflection angle is 5° to 20°, and the argon gas flow rate is 0 L / min to 60 L / min.

[0009] In the above-mentioned vacuum laser welding method for complex aluminum alloy structures, the vacuum level of the vacuum chamber is ≤100Pa.

[0010] In the above-mentioned vacuum laser welding method for complex aluminum alloy structures, the thickness of the arc-starting plate is not less than the welding butt thickness, and the thickness of the arc-ending plate is not less than the welding butt thickness.

[0011] In the above-mentioned vacuum laser welding method for complex aluminum alloy structures, the angle between the arc-starting plate and the plane of the weld is <5°, and the angle between the arc-ending plate and the plane of the weld is <5°.

[0012] In the above-mentioned vacuum laser welding method for complex aluminum alloy structures, the length of the arc-starting plate is greater than the arc-starting distance of the weld, and the length of the arc-ending plate is greater than the arc-ending distance of the weld.

[0013] In the above-mentioned vacuum laser welding method for complex aluminum alloy structures, if the weld structure is planar or planar curved, the argon gas blowing angle is perpendicular to the weld.

[0014] In the above-mentioned vacuum laser welding method for complex aluminum alloy structures, if the weld structure is a circumferential weld, welding is performed from the center point of the circumferential weld to both sides, and the arc start position and arc end position do not coincide, and the distance is ≥15mm. The argon gas blowing direction is consistent with the welding direction, and the blowing angle is 3° to 15° off the perpendicular plane of the welding direction.

[0015] Compared with the prior art, the present invention has the following advantages: This invention improves the quality of vacuum laser welds on aluminum alloys in industrial production, increases production efficiency, and greatly reduces the time spent on patching, rework welding, and grinding. Attached Figure Description

[0016] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 This is a schematic diagram of the vacuum laser welding equipment provided in an embodiment of the present invention. Detailed Implementation

[0017] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0018] Figure 1 This is a schematic diagram of a vacuum laser welding device provided in an embodiment of the present invention. (Combined with...) Figure 1 This embodiment provides a method for vacuum laser welding of aluminum alloys with complex structures. The method includes: mounting the aluminum alloy workpiece to be welded on a three-jaw chuck, pre-positioning an arc-starting plate and an arc-ending plate at both ends of the weld to be welded to obtain the assembly to be welded; setting the vacuum laser welding parameters for aluminum alloys; placing the assembly to be welded into a vacuum chamber, and performing laser welding according to the vacuum laser welding parameters for aluminum alloys.

[0019] The vacuum laser welding method for aluminum alloys is as follows: After the component is loaded into the fixture, it is placed into a three-jaw chuck and locked. Initiation and termination plates are pre-placed at both ends of the weld seam. Parameters such as laser power, welding speed (for flat welds), rotation speed (for circumferential welds), defocusing amount, and initiation and termination distances are pre-set before the component enters the vacuum chamber for vacuum welding. This embodiment, based on vacuum conditions, achieves laser welding of aluminum alloys with a thickness of 4–15 mm. Research was conducted on its structure and process parameter windows, improving weld formation and internal quality. The welded joint meets mechanical performance requirements and is suitable for large-scale industrial production.

[0020] The parameters for vacuum laser welding of aluminum alloys include laser power, welding speed, defocusing amount, weld arc initiation distance, weld arc termination distance, laser head deflection angle, argon gas flow rate, and weld butt thickness.

[0021] The weld thickness is 4 mm to 15 mm, the weld gap is ≤0.2 mm, and the weld step difference is ≤0.3 mm. The butt joint structure is a lock-bottom structure, the lock bottom is required to be ≥2 mm, and there should be no warping at both ends of the butt joint, and it should fit tightly with the lock bottom.

[0022] The laser power is 3000 W to 9000 W, the welding speed is 10 mm / s to 40 mm / s, the defocusing distance is -15 mm to +15 mm, the arc starting distance of the weld is ≥5 mm, the arc ending distance of the weld is ≥15 mm, the laser head deflection angle is 5° to 20°, and the argon gas flow rate is 0 L / min to 60 L / min.

[0023] The vacuum level of the vacuum chamber is ≤100Pa.

[0024] The thickness of the arc-initiating plate shall not be less than the weld butt joint thickness, and the thickness of the arc-terminating plate shall not be less than the weld butt joint thickness. The angle between the arc-initiating plate and the plane of the weld shall be <5°, and the angle between the arc-terminating plate and the plane of the weld shall be <5°. The length of the arc-initiating plate shall be greater than the arc-initiating distance of the weld, and the length of the arc-terminating plate shall be greater than the arc-terminating distance of the weld.

[0025] If the weld structure is planar or planar curved, the argon gas blowing angle is perpendicular to the weld.

[0026] If the weld structure is a circumferential weld, welding is performed from the center point of the circumferential weld to both sides, and the starting and ending positions of the arc do not coincide, with a spacing of ≥15mm. The direction of argon gas blowing is consistent with the welding direction, and the blowing angle is 3° to 15° off the perpendicular plane of the welding direction.

[0027] The material of the starting and ending arc plates should be the same as the material to be welded. If welding dissimilar materials, the material should be the same as the base material with higher tensile strength. Mechanical removal should be used after welding.

[0028] A vacuum laser welding method for complex aluminum alloy structures is as follows: The weld thickness is 4–15 mm, with a tight fit, gap ≤ 0.2 mm, and step difference ≤ 0.3 mm. The weld structure is a lock-bottom structure, with a lock-bottom thickness ≥ 2 mm, and no warping at either end, ensuring tight contact with the lock-bottom. Pre-placed arc-starting and arc-ending plates are used, with a thickness ≥ weld thickness, an angle < 5° between the arc-starting / ending plate and the weld plane, and a length > arc-starting / ending distance. The material of the arc-starting / ending plate should be the same as the material to be welded; if welding dissimilar materials, it should be the same as the base material with higher tensile strength. Post-weld removal is done mechanically.

[0029] The following process parameters should be incorporated into the program: laser power 3000~9000W, welding speed 10~40mm / s, defocusing distance -15~+15mm, arc initiation distance ≥5mm, arc termination distance ≥15mm, laser deflection angle 5°~20°, and argon flow rate 0~60L / min.

[0030] If the weld structure is planar or planar curved, adjust the argon gas blowing angle to be perpendicular to the weld. If the weld structure is circumferential, weld from the center point of the circumferential weld outwards to both sides, and the start and end points of the arc should not coincide, with a spacing of ≥15mm. The argon gas blowing direction should be consistent with the welding direction, and the blowing angle should be 3-15° off the perpendicular plane of the welding direction.

[0031] Example 1 A vacuum laser welding method for complex aluminum alloy structures is as follows: The weld thickness is 4mm, and the joint is tight with a gap ≤0.2mm and a step difference ≤0.3mm. Before welding, the assembly stop is ground, scraped, and wiped; the surface of the weld to be welded must not be touched by bare hands. The butt joint structure is a lock-bottom structure, with a lock bottom thickness ≥2mm, and no warping at either end, fitting tightly with the lock bottom. Pre-placed arc start and finish plates are used, with a thickness ≥4mm, an angle <5° between the arc start and finish plates and the plane of the weld, and a length >5mm. The material of the arc start and finish plates should be the same as the material to be welded; if welding dissimilar materials, it should be the same as the material with higher tensile strength as the base metal. Mechanical cleaning is used after welding.

[0032] The following process parameters were incorporated into the teaching program: laser power 3000 W, welding speed 25 mm / s, defocusing distance +10 mm, arc initiation distance ≥5 mm, arc termination distance ≥10 mm, laser deflection angle 12°, and argon flow rate 60 L / min. After the teaching was completed, the actual welding began.

[0033] After welding, the weld surface is cleaned and polished.

[0034] The weld quality in this embodiment meets the Class I weld requirements of HB / Z20014-2012 "Laser Welding Process for Aluminum Alloys". The weld surface is silver-white, smooth and free of defects such as pits, misalignment, undercut, and weld beads. The interior is free of defects such as incomplete penetration, lack of fusion, cracks, and porosity. The mechanical properties reach more than 90% of the tensile strength of the base material.

[0035] Example 2 A vacuum laser welding method for complex aluminum alloy structures is as follows: The weld thickness is 4mm, and the joint is tight with a gap ≤0.2mm and a step difference ≤0.3mm. Before welding, the assembly stop is ground, scraped, and wiped; the surface of the weld to be welded must not be touched by bare hands. The butt joint structure is a lock-bottom structure, with a lock bottom thickness ≥2mm, and no warping at either end, fitting tightly with the lock bottom. Pre-placed arc start and finish plates are used, with a thickness ≥4mm, an angle <5° between the arc start and finish plates and the plane of the weld, and a length >5mm. The material of the arc start and finish plates should be the same as the material to be welded; if welding dissimilar materials, it should be the same as the material with higher tensile strength as the base metal. Mechanical cleaning is used after welding.

[0036] The following process parameters were incorporated into the teaching program: laser power 3500 W, welding speed 25 mm / s, defocusing distance +10 mm, arc initiation distance ≥5 mm, arc termination distance ≥10 mm, laser deflection angle 12°, and argon flow rate 60 L / min. After the teaching was completed, the actual welding began.

[0037] After welding, the weld surface is cleaned and polished.

[0038] The weld quality in this embodiment meets the Class I weld requirements of HB / Z20014-2012 "Laser Welding Process for Aluminum Alloys". The weld surface is silver-white, smooth and free of defects such as pits, misalignment, undercut, and weld beads. The interior is free of defects such as incomplete penetration, lack of fusion, cracks, and porosity. The mechanical properties reach more than 90% of the tensile strength of the base material.

[0039] Example 3 A vacuum laser welding method for complex aluminum alloy structures is shown below: The weld thickness is 5mm, and the joint is tight with a gap of ≤0.2mm and a step difference of ≤0.3mm.

[0040] Before welding, the assembly stop should be ground, scraped, and wiped. Do not touch the surface of the weld seam with bare hands.

[0041] The docking structure is a lock-bottom structure, the lock bottom must be ≥2mm, and there must be no warping at both ends of the docking, and it must fit tightly with the lock bottom.

[0042] Pre-set starting and ending arc plates with a thickness ≥ 5 mm, an angle between the starting and ending arc plates and the plane of the weld < 5°, and a length > 5 mm.

[0043] The material of the starting and ending arc plates should be the same as the material to be welded. If welding dissimilar materials, the material should be the same as the base material with higher tensile strength. Mechanical removal should be used after welding.

[0044] The following process parameters were incorporated into the teaching program: laser power 3200 W, welding speed 20 mm / s, defocusing distance +10 mm, arc initiation distance ≥5 mm, arc termination distance ≥10 mm, laser deflection angle 12°, and argon flow rate 60 L / min. After the teaching was completed, the actual welding began.

[0045] After welding, the weld surface is cleaned and polished.

[0046] The weld quality in this embodiment meets the Class I weld requirements of HB / Z20014-2012 "Laser Welding Process for Aluminum Alloys". The weld surface is silver-white, smooth and free of defects such as pits, misalignment, undercut, and weld beads. The interior is free of defects such as incomplete penetration, lack of fusion, cracks, and porosity. The mechanical properties reach more than 90% of the tensile strength of the base material.

[0047] Example 4 A vacuum laser welding method for complex aluminum alloy structures is shown below: The weld thickness is 6mm, and the joint must be tight with a gap ≤0.2mm and a step difference ≤0.3mm. Before welding, the assembly stop must be ground, scraped, and wiped; the surface of the weld to be welded must not be touched by bare hands. The butt joint structure is a lock-bottom structure, with a lock-bottom thickness ≥3mm, and no warping at either end, ensuring a tight fit with the lock-bottom. Pre-placed arc start and finish plates, with a thickness ≥6mm, an angle <5° between the arc start / finish plate and the plane of the weld, and a length >5mm. The material of the arc start / finish plate should be the same as the material to be welded; if welding dissimilar materials, it should be the same as the material with higher tensile strength as the base metal. After welding, mechanical cleaning should be used.

[0048] The following process parameters were incorporated into the teaching program: laser power 4000 W, welding speed 30 mm / s, defocusing distance -10 mm, arc initiation distance ≥5 mm, arc termination distance ≥10 mm, laser deflection angle 12°, and argon flow rate 60 L / min. After the teaching was completed, the actual welding began.

[0049] After welding, the weld surface is cleaned and polished.

[0050] The weld quality in this embodiment meets the Class I weld requirements of HB / Z20014-2012 "Laser Welding Process for Aluminum Alloys". The weld surface is silver-white, smooth and free of defects such as pits, misalignment, undercut, and weld beads. The interior is free of defects such as incomplete penetration, lack of fusion, cracks, and porosity. The mechanical properties reach more than 90% of the tensile strength of the base material.

[0051] Example 5 A vacuum laser welding method for complex aluminum alloy structures is shown below: The weld thickness is 6mm, and the joint must be tight with a gap ≤0.2mm and a step difference ≤0.3mm. Before welding, the assembly stop must be ground, scraped, and wiped; the surface of the weld to be welded must not be touched by bare hands. The butt joint structure is a lock-bottom structure, with a lock-bottom thickness ≥3mm, and no warping at either end, ensuring a tight fit with the lock-bottom. Pre-placed arc start and finish plates, with a thickness ≥6mm, an angle <5° between the arc start / finish plate and the plane of the weld, and a length >5mm. The material of the arc start / finish plate should be the same as the material to be welded; if welding dissimilar materials, it should be the same as the material with higher tensile strength as the base metal. After welding, mechanical cleaning should be used.

[0052] The following process parameters were incorporated into the teaching program: laser power 5000 W, welding speed 30 mm / s, defocusing distance -20 mm, arc initiation distance ≥5 mm, arc termination distance ≥10 mm, laser deflection angle 12°, and argon flow rate 60 L / min. After the teaching was completed, the actual welding began.

[0053] After welding, the weld surface is cleaned and polished.

[0054] The weld quality in this embodiment meets the Class I weld requirements of HB / Z20014-2012 "Laser Welding Process for Aluminum Alloys". The weld surface is silver-white, smooth and free of defects such as pits, misalignment, undercut, and weld beads. The interior is free of defects such as incomplete penetration, lack of fusion, cracks, and porosity. The mechanical properties reach more than 90% of the tensile strength of the base material.

[0055] Example 6 A vacuum laser welding method for complex aluminum alloy structures is shown below: The weld thickness is 6mm, and the joint must be tight with a gap ≤0.2mm and a step difference ≤0.3mm. Before welding, the assembly stop must be ground, scraped, and wiped; the surface of the weld to be welded must not be touched by bare hands. The butt joint structure is a lock-bottom structure, with a lock-bottom thickness ≥3mm, and no warping at either end, ensuring a tight fit with the lock-bottom. Pre-placed arc start and finish plates, with a thickness ≥6mm, an angle <5° between the arc start / finish plate and the plane of the weld, and a length >5mm. The material of the arc start / finish plate should be the same as the material to be welded; if welding dissimilar materials, it should be the same as the material with higher tensile strength as the base metal. After welding, mechanical cleaning should be used.

[0056] The following process parameters were incorporated into the teaching program: laser power 4800 W, welding speed 20 mm / s, defocusing distance 0 mm, arc initiation distance ≥ 5 mm, arc termination distance ≥ 10 mm, laser deflection angle 12°, and argon flow rate 60 L / min. After the teaching was completed, the actual welding began.

[0057] After welding, the weld surface is cleaned and polished.

[0058] The weld quality in this embodiment meets the Class I weld requirements of HB / Z20014-2012 "Laser Welding Process for Aluminum Alloys". The weld surface is silver-white, smooth and free of defects such as pits, misalignment, undercut, and weld beads. The interior is free of defects such as incomplete penetration, lack of fusion, cracks, and porosity. The mechanical properties reach more than 90% of the tensile strength of the base material.

[0059] This embodiment requires a vacuum level ≤ 100Pa and a vacuuming time ≤ 20min. At curve corners, the arc initiation height is ≤ 0.5mm and the arc termination crater depth is ≤ 1mm. This embodiment effectively reduces the area of ​​metal vapor adhering to the product surface, requiring only cleaning of residual metal vapor around the weld.

[0060] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A method for vacuum laser welding of complex aluminum alloy structures, characterized in that... include: The aluminum alloy workpiece to be welded is installed on a three-jaw chuck, and an arc-starting plate and an arc-ending plate are pre-placed at both ends of the weld seam to be welded to obtain the assembly to be welded. Set the parameters for vacuum laser welding of aluminum alloy; The components to be welded are placed in a vacuum chamber, and laser welding is performed according to the vacuum laser welding parameters for aluminum alloys.

2. The vacuum laser welding method for complex aluminum alloy structures according to claim 1, characterized in that: The parameters for vacuum laser welding of aluminum alloys include laser power, welding speed, defocusing amount, weld arc initiation distance, weld arc termination distance, laser head deflection angle, argon gas flow rate, and weld butt thickness.

3. The vacuum laser welding method for complex aluminum alloy structures according to claim 2, characterized in that: The thickness of the weld joint is 4 mm to 15 mm, the gap between the weld joints is ≤0.2 mm, and the step difference between the weld joints is ≤0.3 mm.

4. The vacuum laser welding method for complex aluminum alloy structures according to claim 2, characterized in that: The laser power is 3000 W to 9000 W, the welding speed is 10 mm / s to 40 mm / s, the defocusing distance is -15 mm to +15 mm, the arc starting distance of the weld is ≥5 mm, the arc ending distance of the weld is ≥15 mm, the laser head deflection angle is 5° to 20°, and the argon gas flow rate is 0 L / min to 60 L / min.

5. The vacuum laser welding method for complex aluminum alloy structures according to claim 1, characterized in that: The vacuum level of the vacuum chamber is ≤100Pa.

6. The vacuum laser welding method for complex aluminum alloy structures according to claim 1, characterized in that: The thickness of the arc-starting plate shall not be less than the welding butt thickness, and the thickness of the arc-ending plate shall not be less than the welding butt thickness.

7. The vacuum laser welding method for complex aluminum alloy structures according to claim 1, characterized in that: The angle between the arc-starting plate and the plane of the weld is <5°, and the angle between the arc-ending plate and the plane of the weld is <5°.

8. The vacuum laser welding method for complex aluminum alloy structures according to claim 1, characterized in that: The length of the arc-starting plate is greater than the arc-starting distance of the weld, and the length of the arc-ending plate is greater than the arc-ending distance of the weld.

9. The vacuum laser welding method for complex aluminum alloy structures according to claim 1, characterized in that: If the weld structure is planar or planar curved, the argon gas blowing angle is perpendicular to the weld.

10. The vacuum laser welding method for complex aluminum alloy structures according to claim 1, characterized in that: If the weld structure is a circumferential weld, welding is performed from the center point of the circumferential weld to both sides, and the starting and ending positions of the arc do not coincide, with a spacing of ≥15mm. The direction of argon gas blowing is consistent with the welding direction, and the blowing angle is 3° to 15° off the perpendicular plane of the welding direction.

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