Titanium alloy thick plate particle filling multi-pass laser welding method

Abstract

The invention discloses a titanium alloy thick plate particle filling multi-pass laser welding method which is suitable for laser welding of titanium alloy thick plates with the plate thickness larger than 25 mm and comprises the following steps that S1, titanium alloy particles are prepared; s2, titanium alloy particles are cleaned and dried; s3, the to-be-welded workpiece and the fixing tool are assembled according to the welding requirement, and spot welding and fixing are conducted at the two ends of a welding bead of the workpiece through laser welding; s4, filling the first weld joint with dried titanium alloy particles, then carrying out laser welding under argon protection, carrying out particle filling and laser welding on a second weld joint after welding, and so on until the required welding thickness is reached; and S5, after welding is completed, the light source and the gas are turned off, the clamp is dismantled, the weld joint surface is cleaned, and welding is completed. According to the method, high-quality connection of the titanium alloy thick plates is achieved by adjusting components of titanium alloy particles, and the purposes of reducing welding defects and improving the mechanical property of a welded joint are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of titanium alloy welding, and in particular relates to a particle-filled multi-pass laser welding method for a titanium alloy thick plate. Background Art

[0002] Titanium alloys are widely used in high-temperature, high-pressure and corrosion-resistant environments such as aerospace, petrochemical, and marine engineering due to their high specific strength, high corrosion resistance, and high-temperature performance. As titanium alloy products develop towards integration, large-scale, and high-strength, efficient and high-quality welding of titanium alloy thick plates has become a technical problem that needs to be solved urgently.

[0003] Traditional titanium alloy welding methods mostly use tungsten inert gas arc welding, which uses a multi-layer and multi-pass wire method to weld thick plates to meet the requirements of large penetration depth for thick plate welding. However, its disadvantages are also obvious. First, the high heat input of the arc welding method can easily lead to large deformation of the workpiece and high residual stress, which not only affects the accuracy and appearance of the weldment, but may also lead to serious problems such as decreased joint performance and cracking in the brittle zone. Secondly, welding thick plates requires special groove design and complex process requirements, resulting in low welding efficiency and high production costs. In addition, as the thickness of the parent material increases, it becomes increasingly difficult to control welding defects during the arc welding process, making it difficult to produce qualified weldments that meet quality requirements.

[0004] Laser welding has many advantages such as high energy density, small welding deformation, and high welding efficiency, and has become one of the potential technical means for titanium alloy welding. At present, laser welding of titanium alloy thick plates is mostly carried out by multi-pass wire feeding. However, this method requires special groove design and strict process (such as wire feeding speed, relative position of wire feeding point and light beam) to ensure welding quality. At the same time, during multi-pass wire feeding laser deep melting welding, the uneven spatial distribution of alloy elements in the weld area may cause serious cracking problems. The use of low-frequency electromagnetic field to stir the molten pool electromagnetically can reduce the tendency of element unevenness, but the engineering application cost is relatively high. In addition, the use of multi-pass wire feeding laser welding of thick plates often results in poor side wall fusion. These problems seriously restrict the laser welding quality and welding production efficiency of titanium alloy thick plates.

[0005] It can be seen that the existing technology has many shortcomings in the welding of titanium alloy thick plates. Although arc welding technology represented by argon arc welding can meet certain welding penetration requirements, it has obvious defects in welding deformation, efficiency and defect control; although laser wire feeding multi-pass welding technology has the advantages of high efficiency and low deformation, the current multi-pass wire feeding strategy for welding thick plates also has great process difficulties, and it is also impossible to achieve the regulation of the chemical composition and mechanical properties of the welded joints. Therefore, it is urgent to develop a new titanium alloy thick plate laser welding method to overcome the limitations of the existing technology and achieve high-quality welding of titanium alloy thick plates. Summary of the invention

[0006] The purpose of the present invention is to provide a particle-filled multi-pass laser welding method for titanium alloy thick plates, which achieves high-quality connection of titanium alloy thick plates by adjusting the composition of titanium alloy particles, thereby achieving the purpose of reducing welding defects and improving the mechanical properties of welded joints, and has important engineering significance for improving the welding quality of titanium alloy thick plates.

[0007] The technical solution adopted by the present invention is a multi-pass laser welding method for titanium alloy thick plates with particle filling, which is suitable for laser welding of titanium alloy thick plates with a thickness greater than 25 mm, and comprises the following steps: Step S1, preparing titanium alloy particles; Step S2, cleaning and drying the titanium alloy particles; Step S3, assembling the workpiece to be welded and the fixing fixture according to the welding requirements, and fixing the workpiece at the two ends of the weld bead by laser welding; Step S4, using dried titanium alloy particles to fill the first weld, and then performing laser welding under argon protection, and after welding, performing particle filling and laser welding of the second weld, and so on, until the required welding thickness is reached; Step S5: After welding is completed, turn off the light source and gas, remove the fixture, clean the weld surface, and the welding is completed.

[0008] The present invention is also characterized in that: In step S1, the prepared titanium alloy particles are cut into particles by a shearing die using a commercial titanium alloy welding wire; wherein the wire diameter is D, and the particle length is controlled to be 0.8-1.2D, D=φ0.8~2.4mm; Alternatively, in step S1, the prepared titanium alloy particles are regular or irregular particles, with a volume equivalent diameter ranging from 0.85 mm to 2.92 mm and a major-minor axis ratio of 1 to 1.2.

[0009] In step S2, the processed titanium alloy particles are placed in an ultrasonic cleaning machine and ultrasonically cleaned with an acetone solution for 10 to 15 minutes, and then taken out and placed in a drying oven for drying at a temperature of 100° C. to 150° C. for 20 to 30 minutes.

[0010] In step S3, when the workpiece to be welded is assembled with the fixed fixture, the ceramic lining plate needs to be adhered to the back of the weld with aluminum foil tape.

[0011] In step S3, the material of the workpieces to be welded is the same material or different material of titanium alloy.

[0012] In step S4, along the thickness direction of the weld of the butt joint of the workpiece to be welded, the titanium alloy particles used in each pass from the root weld to the cover weld are made of the same material or different materials.

[0013] In step S4, along the thickness direction of the butt joint weld, the titanium alloy particle filling thickness range of the root weld is 8mm-12mm, and the titanium alloy particle filling thickness range of the cover weld is 4mm-8mm. The number of intermediate passes is determined according to the thickness of the parent material, and the filling thickness of a single pass is 5mm-15mm.

[0014] Before step S1, the method further includes the following steps: Step ST1: Processing the weld groove of the workpiece to be welded into an I-shaped groove by symmetrical surface processing according to the design drawing; Step ST2: Use acetone to clean the groove of the workpiece to be welded and the 10mm-20mm area on both sides to remove oil stains, and then blow dry with hot air.

[0015] In step S4, an argon gas shield is used to protect the welding pool, and pre-ventilation is performed for 10s-20s before each laser welding pass, with an argon gas flow rate of 20L / min-35L / min.

[0016] In step S4, the laser light source power is 2KW-88KW, and the welding speed is 200 mm / min-800 mm / min.

[0017] The beneficial effects of the present invention are: (1) The particle-filled multi-pass laser welding method for titanium alloy thick plates described in the present invention effectively solves the problems of large welding material consumption, complex process, and low efficiency in conventional tungsten inert gas welding methods by filling titanium alloy particles. It effectively solves the technical difficulty of difficult welding of thick plates by laser welding methods without filling materials. It effectively solves the technical difficulties of high process requirements, poor side wall fusion, and inability to adjust the composition of wire feeding laser welding methods. It can achieve precise control of the composition and performance of titanium alloy thick plate butt joints in the thickness direction, effectively reduce the occurrence of welding defects in titanium alloy thick plate joints, and improve the problems of poor strength and toughness matching and structural unevenness of welded joints.

[0018] (2) The multi-pass laser welding method for alloy thick plates with particle filling described in the present invention has relatively simple process requirements. The weldment only needs to level the butt surfaces for assembly welding, and does not require the processing of complex grooves. In addition, this method can also make full use of the characteristics of laser welding equipment that can be easily automated, greatly improve welding construction efficiency, and improve the welding quality of complex structure titanium alloy thick plate joints. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of a wire shearing die used in processing titanium alloy particles according to the method of the present invention; Figure 2 It is a schematic diagram of filling titanium alloy particles between workpieces to be welded and performing welding according to the method of the present invention.

[0020] In the figure, 1. shearing die, 2. titanium alloy welding wire, 3. fixed die, 4. laser welding gun, 5. nitrogen protection hood, 6. workpiece to be welded, 7. titanium alloy particles, 8. ceramic lining. DETAILED DESCRIPTION

[0021] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] The present invention provides a titanium alloy thick plate particle filling multi-pass laser welding method, which is suitable for laser welding of titanium alloy thick plates with a plate thickness greater than 25 mm, and comprises the following steps: Step S1, preparing titanium alloy particles 7; In step S1, the prepared titanium alloy particles are cut into particles by a shearing die using a commercial titanium alloy welding wire; wherein the wire diameter is D, and the particle length is controlled to be 0.8-1.2D, D=φ0.8~2.4mm; Alternatively, in step S1, the prepared titanium alloy particles are regular or irregular particles, with a volume equivalent diameter ranging from 0.85 to 2.92 mm and a major-minor axis ratio of 1 to 1.2.

[0023] The titanium alloy welding wire is cut into particles by a shearing die. Figure 1 As shown, specifically: the titanium alloy welding wire 2 is installed on the fixed cutting die 3, and the shearing cutting die 1 shears the titanium alloy welding wire 2 to shear the titanium alloy welding wire 2 into particles.

[0024] Before step S1, the method further includes the following steps: Step ST1: Processing the weld groove of the workpiece 6 to be welded into an I-shaped groove by symmetrical surface processing according to the design drawing; Step ST2: Use acetone to clean the groove of the workpiece to be welded and the 10mm-20mm area on both sides to remove oil stains, and then blow dry with hot air.

[0025] Step S2, cleaning and drying the titanium particles; In step S2, the processed titanium alloy particles 7 are placed in an ultrasonic cleaning machine and ultrasonically cleaned with an acetone solution for 10 to 15 minutes, and then taken out and placed in a drying oven for drying at a temperature of 100° C. to 150° C. for 20 to 30 minutes.

[0026] like Figure 2 As shown, step S3, assembling the workpiece to be welded and the fixing tool according to the welding requirements, and using laser welding to fix the two ends of the weld bead of the workpiece; like Figure 2 As shown, in step S3, when the workpiece 6 to be welded is assembled with the fixed tooling, the ceramic lining plate 8 needs to be adhered to the back of the weld with aluminum foil tape; In step S3, the material of the workpieces to be welded is the same material or different material of titanium alloy.

[0027] Step S4, using the dried titanium alloy particles 7 to fill the first weld, and then performing laser welding under argon protection, and after welding, performing particle filling and laser welding of the second weld, and so on, until the required welding thickness is reached; In step S4, along the thickness direction of the butt joint weld of the workpiece 6 to be welded, the titanium alloy particles 7 used in each pass from the root weld to the cap weld are made of the same material or different materials.

[0028] In step S4, along the thickness direction of the butt joint weld, the titanium alloy particles 7 filling thickness range of the root weld is 8mm-12mm, and the titanium alloy particles 7 filling thickness range of the cover weld is 4mm-8mm. The number of intermediate passes is determined according to the thickness of the parent material, and the filling thickness of a single pass is 5mm-15mm.

[0029] like Figure 2 As shown, in step S4, an argon gas protection hood 5 is used to perform gas protection on the welding molten pool, and pre-ventilation is performed for 10s-20s before each laser welding pass, with an argon gas flow rate of 20L / min-35L / min.

[0030] like Figure 2 As shown, in step S4, the laser light source power used by the laser welding gun 4 is 2KW-8KW, and the welding speed is 200mm / min-800mm / min.

[0031] Step S5: After welding is completed, turn off the light source and gas, remove the fixture, clean the weld surface, and the welding is completed.

[0032] Example 1 The present invention provides a multi-pass laser welding method for titanium alloy thick plate with particle filling, and the specific process steps are as follows: TA18 and TC4 (Ti-6Al-4V) titanium alloy welding wires with a diameter of φ1.2mm are processed into particles through a shearing die, and the particle size is φ1.2mm×1.2mm. Then, the processed two titanium alloy particles are respectively placed in an ultrasonic cleaning machine and ultrasonically vibrated and cleaned with acetone solution for 10 minutes, and then taken out and placed in a drying box for drying at a drying temperature of 120°C for 20 minutes, and then used for standby after drying.

[0033] The butt surfaces of two TC4 titanium alloy workpieces to be welded (δ35×300×600mm) were milled, and the groove was polished within 20mm on both sides. Then, the groove and its vicinity were cleaned with acetone to remove oil stains, and then dried with a hot air blower.

[0034] According to the welding requirements, the workpiece to be welded is assembled with the fixed fixture, the assembly gap is adjusted to 2.5mm, the misalignment is controlled to be less than 0.2mm, the ceramic liner is pasted on the back of the weld with aluminum foil tape, and the two ends of the weld of the workpiece are welded and fixed by laser welding. Then the welding parameters are set according to the welding process, titanium alloy particles are filled, and the root pass welding, the middle pass welding and the final pass (covering) welding are carried out in sequence. After the welding is completed, the fixture is removed after cooling to room temperature, and the weld surface is cleaned. The welding is completed.

[0035] Specific laser welding process: Use dried TA18 titanium alloy particles to fill the root weld, the filling thickness is 9mm, and then perform laser welding under argon protection. The second and third welds are filled and welded with TC4 titanium alloy particles, and the filling thickness is 8mm and 11mm respectively. The last weld is filled with TA18 titanium alloy particles and welded to achieve the required welding thickness. The laser power is 3KW-5KW, and the welding speed is 200mm / min-300mm / min. The entire welding process is carried out under argon protection. Argon is filled for 20s before welding, and the gas is turned off after 20s of argon filling after welding is completed. The argon flow rate is 30L / min.

[0036] Through particle filling laser welding, the element composition in the thickness direction of the weld joint was adjusted. TA18 particles were used to fill the root weld and the upper weld, and TC4 titanium alloy particles were used to fill the center weld. The nominal chemical composition of TA18 titanium material is Ti-3Al-2.5V, in which the Al and V content are lower than TC4 titanium material (Ti-6Al-4V), and its welding performance and plasticity are better than TC4. The use of TA18 titanium alloy particles with better weldability in the root weld and the upper weld can optimize the proportion of elements in the joint molten pool, reduce the martensite content in the organization during the cooling stage, appropriately reduce the hardness of the upper and lower joints, and improve the impact performance. The use of TC4 titanium alloy particles when welding the middle weld is conducive to improving the overall strength of the weld. At the same time, the preheating effect of the root weld and the heat treatment effect of the upper weld on the middle weld can significantly improve the weldability of TC4 and reduce the occurrence of welding defects in the middle weld. Adjusting the composition of titanium alloy particles is used to achieve high-quality connection of titanium alloy thick plates, thereby reducing welding defects and improving the mechanical properties of welded joints. This has important engineering significance for improving the welding quality of titanium alloy thick plates.

[0037] After welding, the workpiece was subjected to Class B double-sided and double-sided nondestructive testing in accordance with the NB / T47013.3-2023 standard, and the welded joints met the Class I quality requirements. The mechanical property specimens of the workpiece were processed and tested. The average tensile strength of the upper, middle and lower three areas of the titanium alloy thick plate particle-filled multi-pass laser welding joint was ±10MPa, and the average impact toughness was ±6J. Compared with the results of tungsten inert gas arc welding and laser wire feeding multi-pass welding, the particle-filled multi-pass laser welding method reduced the occurrence of welding defects and significantly improved the uniformity and toughness of the mechanical properties of the thick plate joints. It can be seen that the particle-filled multi-pass laser welding method for titanium alloy thick plates provided by the present invention effectively improves the quality of titanium alloy thick plate laser welding joints.

[0038] Example 2 In this embodiment, TA2 (TiELI) welding wire with a diameter of φ1.2 mm is used to process the filling particles. The particle size is φ1.2 mm×1.2 mm. The processed titanium alloy particles are placed in an ultrasonic cleaning machine and ultrasonically cleaned with an acetone solution for 12 minutes. After that, they are taken out and placed in a drying box for drying at a temperature of 120°C for 25 minutes. It is used to weld TC4 titanium alloy with a base material thickness of 30 mm, and three passes are used for welding, and the particle filling thickness of each pass is 12 mm, 10 mm, and 8 mm, respectively, to achieve a reliable connection of the low-strength matching TC4 titanium alloy laser welding head. The undisclosed technical features in this embodiment are the same as those in Example 1.

[0039] Example 3 In this embodiment, TC3 (Ti-5Al-4V) and TC4 welding wires with a diameter of φ2 mm are used to process the filling particles. The particle size is φ2 mm × 2.4 mm. The processed titanium alloy particles are placed in an ultrasonic cleaning machine and ultrasonically cleaned with an acetone solution for 15 minutes. After that, they are taken out and placed in a drying oven for drying at a temperature of 150° C. for 30 minutes. For welding TC4 titanium alloy with a base material thickness of 50mm, the first and last welds are filled with TC3 titanium particles, the middle pass is filled with TC4 titanium particles, and 5 passes are used for welding. The particle filling thickness of each pass is 12mm, 7mm, 10mm, 13mm, and 8mm, respectively. The laser power is 5KW-8KW, the welding speed is 300mm / min-600mm / min, and the argon gas flow rate is 35L / min, achieving reliable connection of equal strength matching TC4 titanium alloy laser welding heads. The undisclosed technical features in this embodiment are the same as those in Example 1.

[0040] Example 4 In this embodiment, TA2 (TiELI) welding wire with a diameter of φ1.6 mm is used to process the filling particles, and the particle size is φ1.6 mm×1.9 mm. The processed titanium alloy particles are placed in an ultrasonic cleaning machine and ultrasonically cleaned with an acetone solution for 10 minutes, and then taken out and placed in a drying box for drying at a temperature of 100°C for 20 minutes. Used to weld TA18 titanium alloy with a base material thickness of 40mm, 4 passes are used for welding, and the particle filling thickness of each pass is 12mm, 10mm, 12mm, and 6mm respectively. The laser power is 3KW-7.5KW, the welding speed is 600mm / min-800mm / min, and the argon flow rate is 35L / min, which realizes the reliable connection of the low-strength matching TA18 titanium alloy laser welding head.

[0041] The undisclosed technical features in this embodiment are the same as those in Embodiment 1. Example 5 In this embodiment, φ1.2mm TC3 (Ti-5Al-4V) and TC4 welding wires are used to process filling particles with a particle size of φ1.2mm×1.2mm. They are used to weld TC4 titanium alloy and TC11 (Ti-6.5A1-3.5Mo-1.5Zr-0.3Si) titanium alloy with a base material thickness of 25mm. Four passes are used for welding. The first and last welds are filled with TC3 titanium particles, and the intermediate passes are filled with TC4 titanium particles. The particle filling thickness of each pass is 8mm, 5mm, 8mm, and 4mm, respectively. The laser power is 2KW-5KW, and the welding speed is 200mm / min-400mm / min. Pre-ventilation is performed for 10s before each laser welding pass, and the argon gas flow rate is 20L / min. After welding, the weldment is annealed to achieve high-quality connection of dissimilar titanium alloy laser welding heads.

[0042] The undisclosed technical features in this embodiment are the same as those in Embodiment 1.

[0043] Example 6 In this embodiment, φ1.0mm TA18 (Ti-3Al-2.5V) welding wire is used to process filling particles with a particle size of φ1.0mm×1.1mm for welding TA15 (Ti-6.5Al-1Mo-1V-2Zr) titanium alloy with a base material thickness of 28mm. Four passes are used for welding, and the particle filling thickness of each pass is 8mm, 6mm, 9mm, and 5mm respectively. The laser power is 2.5KW-5KW, and the welding speed is 200mm / min-400mm / min. Before each laser welding pass, pre-ventilation is performed for 15s, and the argon flow rate is 25L / min. After welding, the weldment is annealed to achieve a reliable connection of the TA15 titanium alloy thick plate laser welding head.

[0044] The undisclosed technical features in this embodiment are the same as those in Embodiment 1.

[0045] Example 7 In this embodiment, TA18 titanium alloy particles are used, and the volume equivalent diameter range is 0.85 mm, and the major-minor axis ratio is 1.2; The undisclosed technical features in this embodiment are the same as those in Embodiment 6.

[0046] Example 8 In this embodiment, TA18 titanium alloy particles are used, whose volume equivalent diameter range is 2.92 mm and the major-minor axis ratio is 1; The undisclosed technical features in this embodiment are the same as those in Embodiment 6.

[0047] Example 9 In this embodiment, TA18 titanium alloy particles are used, and the volume equivalent diameter range is 2.45 mm, and the major-minor axis ratio is 1.1; The undisclosed technical features in this embodiment are the same as those in Embodiment 6.

[0048] The method provided by the present invention can achieve reliable connection of the same or different titanium alloy thick plates, and obtain high-quality titanium alloy thick plate laser welding heads. Compared with wire feeding TIG welding, laser autogenous welding and laser wire feeding welding methods of titanium alloy thick plates, it has the technical advantages of simple process and fewer defects. At the same time, it can also improve the uniformity and toughness of the mechanical properties of the thick plate joints through the diversified combination of filling welding material particles, which is a technical advantage that other welding methods do not have.

Claims

1. A multi-pass laser welding method for titanium alloy thick plate with particle filling, characterized in that: It is suitable for laser welding of titanium alloy thick plates with a thickness greater than 25 mm, including the following steps: Step S1, preparing titanium alloy particles; Step S2, cleaning and drying the titanium alloy particles; Step S3, assembling the workpiece to be welded and the fixing fixture according to the welding requirements, and fixing the workpiece at the two ends of the weld bead by laser welding; Step S4, using dried titanium alloy particles to fill the first weld, and then performing laser welding under argon protection, and after welding, performing particle filling and laser welding of the second weld, and so on, until the required welding thickness is reached; Step S5: After welding is completed, turn off the light source and gas, remove the fixture, clean the weld surface, and the welding is completed.

2. The particle-filled multi-pass laser welding method for titanium alloy thick plates according to claim 1 is characterized in that: In step S1, the prepared titanium alloy particles are cut into particles by a shearing die using a commercial titanium alloy welding wire; wherein the wire diameter is D, and the particle length is controlled to be 0.8-1.2D, D=φ0.8~2.4mm; Alternatively, in step S1, the prepared titanium alloy particles are regular or irregular particles, with a volume equivalent diameter ranging from 0.85 mm to 2.92 mm and a major-minor axis ratio of 1 to 1.

2.

3. The particle-filled multi-pass laser welding method for titanium alloy thick plates according to claim 1 is characterized in that: In step S2, the processed titanium alloy particles are placed in an ultrasonic cleaning machine and ultrasonically cleaned with an acetone solution for 10 to 15 minutes, and then taken out and placed in a drying oven for drying at a temperature of 100° C. to 150° C. for 20 to 30 minutes.

4. The method for multi-pass laser welding of titanium alloy thick plates with particle filling according to claim 1, characterized in that: In step S3, when the workpiece to be welded is assembled with the fixed tooling, the ceramic lining plate needs to be adhered to the back of the weld with aluminum foil tape; in step S3, the material of the workpiece to be welded is the same material or a different material of titanium alloy.

5. The method for multi-pass laser welding of titanium alloy thick plates with particle filling according to claim 1, characterized in that: In step S4, along the thickness direction of the weld of the butt joint of the workpiece to be welded, the titanium alloy particles used in each pass from the root weld to the cover weld are made of the same material or different materials.

6. The particle-filled multi-pass laser welding method for titanium alloy thick plates according to claim 1, characterized in that: In step S4, along the thickness direction of the butt joint weld, the titanium alloy particle filling thickness range of the root weld is 8mm-12mm, and the titanium alloy particle filling thickness range of the cover weld is 4mm-8mm. The number of intermediate passes is determined according to the thickness of the parent material, and the filling thickness of a single pass is 5-15mm.

7. The particle-filled multi-pass laser welding method for titanium alloy thick plate according to claim 1, characterized in that: Before step S1, the method further includes the following steps: Step ST1: Processing the weld groove of the workpiece to be welded into an I-shaped groove by symmetrical surface processing according to the design drawing; Step ST2: Use acetone to clean the groove of the workpiece to be welded and the 10mm-20mm area on both sides to remove oil stains, and then blow dry with hot air.

8. The particle-filled multi-pass laser welding method for titanium alloy thick plates according to claim 1 is characterized in that: In step S4, an argon gas shielding hood is used to protect the welding molten pool, and pre-ventilation is performed for 10s-20s before each laser welding pass, with an argon gas flow rate of 20L / min-35L / min.

9. The particle-filled multi-pass laser welding method for titanium alloy thick plates according to claim 1, characterized in that: In step S4, the laser light source power is 2KW-88KW, and the welding speed is 200 mm / min-800 mm / min.

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