A high-temperature titanium alloy laser welding process

Abstract

The present invention discloses a high-temperature titanium alloy laser welding process, comprising the following steps: (1) forming a titanium film layer on the surface of iron powder by magnetron sputtering technology to wrap the iron powder particles, thereby obtaining Fe / Ti composite powder; (2) placing Fe / Ti composite powder in the gap between the high-temperature titanium alloy to be welded to form an intermediate layer, and ensuring a tight connection between the titanium alloy-Fe / Ti composite powder-titanium alloy; (3) performing laser welding to completely melt the intermediate layer and partially melt the titanium alloy layers on both sides to form a weld; (4) heating the weldment to 500-600°C for insulation, and then cooling. This process has a stable welding process, a high welding success rate, beautiful weld formation, a small heat-affected zone, and no cracks, pores, undercuts, or penetration defects. It improves the overall mechanical properties and meets the requirements of large-scale and integrated aircraft engines.

Description

Technical Field

[0001] The present invention belongs to the technical field of material welding (connection), and in particular relates to a high-temperature titanium alloy laser welding process. Background Art

[0002] Titanium alloys, with their exceptional strength-to-weight ratio, low thermal conductivity, and excellent corrosion resistance, are widely used in the aerospace field, significantly improving engine thrust-to-weight ratios and service capabilities. As aerospace vehicles continue to grow in size, complexity, and integration, laser welding, with its advantages such as low spatter, minimal heat-affected zone, and aesthetically pleasing welds, has become a popular and widely used welding technology.

[0003] Currently, laser welding of titanium alloys is prone to developing porosity defects in the weld due to gas entrapment. Furthermore, titanium alloys' low thermal conductivity and high coefficient of thermal expansion make them susceptible to significant welding stress and deformation, leading to cracks and poor mechanical properties in the weld area. Therefore, a process is needed to optimize the microstructure and performance of titanium alloy laser welding. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies and defects mentioned in the above background technology, provide a high-temperature titanium alloy laser welding process, and improve the performance of titanium alloy laser welding welds.

[0005] In order to solve the above technical problems, the technical solution proposed by the present invention is:

[0006] A high-temperature titanium alloy laser welding process comprises the following steps:

[0007] (1) A titanium film layer is formed on the surface of the iron powder by magnetron sputtering technology to wrap the iron powder particles to obtain Fe / Ti composite powder;

[0008] (2) Place Fe / Ti composite powder in the gap of the high-temperature titanium alloy to be welded to form an intermediate layer, and ensure that the titanium alloy-Fe / Ti composite powder-titanium alloy is tightly connected;

[0009] (3) Laser welding is performed to completely melt the middle layer and partially melt the titanium alloy layers on both sides to form a weld;

[0010] (4) Heat the weldment to 500~600℃ and keep it warm, then cool it.

[0011] As a further improvement, the iron powder size in step (1) is controlled to be 150-250 μm.

[0012] As a further improvement, in the Fe / Ti composite powder of step (1), the Ti film accounts for 4.5-5.5% of the total mass of the Fe / Ti composite powder.

[0013] As a further improvement, step (1) uses a magnetron sputtering device with a vibration function.

[0014] As a further improvement, the target material used for magnetron sputtering in step (1) is high-purity titanium, the sputtering gas is argon, the sputtering pressure is 8~20Pa, and the sputtering current is 60~80mA.

[0015] As a further improvement, the vibration motor speed of the magnetron sputtering equipment in step (1) is 400-600 r / min, the deposition times are 3-6 times, and the vibration motor works for 10-15 minutes each time.

[0016] As a further improvement, in step (2), the assembly gap of the titanium alloy to be welded is 0.1-0.3 mm.

[0017] As a further improvement, in step (2), the preload force at the titanium alloy-Fe / Ti composite powder-titanium alloy interface is controlled at 20-30N.

[0018] As a further improvement, in step (3), the laser power of the laser welding is 500-800 W, the laser control current is 60-80 A, the laser pulse frequency is 6-10 Hz, and the welding speed is 500-1500 mm / min.

[0019] As a further improvement, it is characterized in that step (4) is kept warm for 2 to 8 hours.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention effectively reduces weld porosity defects and refines weld grain structure by introducing iron elements into the weld area. Fe / Ti composite powder is prepared as an intermediate layer using vibration magnetron sputtering and laser welding processes. The titanium film on the surface of the iron powder has good bonding with the titanium alloy, which increases the welding success rate and improves the interface connection properties. A small amount of Fe-Ti solid solution appears in the weld structure, which refines the grains and introduces a solid solution strengthening mechanism, thereby improving the overall mechanical properties. The welding process of this process is stable, the weld is beautifully formed, the heat-affected zone is small, and there are no cracks, pores, undercuts, or penetration defects, meeting the large-scale and integrated requirements of aircraft engines. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 Schematic diagram of vibration magnetron sputtering and laser welding of the present invention;

[0024] Figure 2 Figure 1 is the powder morphology before and after vibration magnetron sputtering of Example 1, Figure a is the morphology before sputtering, and Figure b is the morphology after sputtering;

[0025] Figure 3 The left figure is the line scan analysis diagram and energy spectrum distribution diagram of the weld area in Example 1. The right figure is the energy spectrum distribution diagram of the yellow line area in the left figure. The ordinate is the relative content of the elements, and the abscissa is the distance from the left to the right weld area.

[0026] Figure 4 The line scan analysis diagram and energy spectrum distribution diagram of the weld area in Example 2 are shown. The left figure is the line scan analysis diagram of the weld area, and the right figure is the energy spectrum distribution diagram of the yellow line area in the left figure. The ordinate is the relative content of the elements, and the abscissa is the distance from the left to the right weld area.

[0027] Figure 5 The line scan analysis diagram and energy spectrum distribution diagram of the weld area in Example 3 are shown. The left figure is the line scan analysis diagram of the weld area, and the right figure is the energy spectrum distribution diagram of the yellow line area in the left figure. The ordinate is the relative content of the elements, and the abscissa is the distance from the left to the right weld area.

[0028] Figure 6 These are the line scanning analysis diagram and energy spectrum distribution diagram of the weld area in Example 4. The left figure is the line scanning analysis diagram of the weld area, and the right figure is the energy spectrum distribution diagram of the yellow line area in the left figure. The vertical axis is the relative content of the elements, and the horizontal axis is the distance from the left to the right weld area. DETAILED DESCRIPTION

[0029] To facilitate understanding of the present invention, the present invention will be described in more comprehensive and detailed form below in conjunction with the accompanying drawings and preferred embodiments. However, the protection scope of the present invention is not limited to the following specific embodiments.

[0030] Unless otherwise defined, all technical terms used hereinafter have the same meanings as those generally understood by those skilled in the art. The technical terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0031] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0032] In some specific embodiments, the high temperature titanium alloy laser welding process of the present invention comprises the following steps:

[0033] (1) A titanium film layer is formed on the surface of iron powder by magnetron sputtering technology to obtain Fe / Ti composite powder (Fe-Ti composite powder).

[0034] In some embodiments, the iron powder size is controlled to be about 150-250 μm.

[0035] In some embodiments, the iron powder is first ultrasonically cleaned with acetone, deionized water, and anhydrous ethanol in sequence and then dried in a vacuum drying oven (the oven temperature is 60-80° C.).

[0036] In some embodiments, a magnetron sputtering device with a vibration function is used. Figure 1 In the left picture, iron powder is placed on a vibration table, and a pure titanium target is placed on top. A layer of titanium film is magnetron sputtered on the surface of the vibrated iron powder particles. The vibrating iron powder helps to form a uniform titanium film layer on the surface.

[0037] In some embodiments, the target material used is a high-purity titanium target (99.99% purity), the sputtering gas is argon (99.99% purity), the sputtering pressure is 8-20 Pa, the sputtering current is 60-80 mA, the deposition frequency is 3-6, the vibration motor operates for 10-15 minutes per pass, the speed is 400-600 rpm, and the amount of Fe powder sputtered per pass is 1g. A small amount and multiple sputtering processes are used to ensure uniform film coverage.

[0038] After sputtering, a nano-sized titanium film is coated on the surface of the iron powder particles with a film thickness of about 2~3μm. The Ti film accounts for about 5% of the total mass of the Fe / Ti composite powder, forming an approximate core-shell structure.

[0039] As a strong β-phase stabilizer, iron, when present in small amounts in α-type titanium alloys, can lower the β / α transition temperature, expand the β-phase region, and thereby enhance the alloy's high-temperature plasticity and reduce weld cracking susceptibility. In near-β-type titanium alloys, the appropriate addition of iron can optimize the β-phase ratio and improve the plasticity of the weld zone. Furthermore, trace iron additions may reduce weld pool viscosity and facilitate gas escape. Furthermore, the iron interlayer absorbs some of the weld metal's energy during welding, making the weld pool's temperature distribution more uniform, reducing overheating, lowering metal vapor generation, and ultimately, minimizing porosity. The iron interlayer exhibits a degree of activity within the weld pool, influencing weld metal solidification, promoting nucleation within the weld metal, and refining the grain size. This refined grain size enhances weld metal strength and toughness. The resulting Fe-Ti solid solution also acts as a solute strengthening agent, enhancing weld metal strength and improving its overall mechanical properties.

[0040] The present invention introduces vibration magnetron sputtering technology, and magnetron sputters a layer of titanium film on the surface of iron powder as an intermediate layer powder. The titanium film on the surface of the iron powder can maintain good interface bonding with the titanium alloy, further improving the interface connection properties, and forming an Fe-Ti solid solution in the weld area, refining the weld grain structure, and improving its comprehensive mechanical properties. In addition, the Fe element can reduce welding defects.

[0041] (2) Place Fe / Ti composite powder in the gap of the high-temperature titanium alloy to be welded to form an intermediate layer, and make the titanium alloy-Fe / Ti composite powder-titanium alloy connection tight, such as Figure 1 Right picture.

[0042] In some embodiments, the titanium alloy sample to be welded is ground to 3000# and then ultrasonically cleaned with acetone and alcohol.

[0043] In some embodiments, the titanium alloy sample to be welded is fixed on a workbench. The weld joint is an I-groove butt weld with an assembly gap of 0.1-0.3 mm. The composite powder is placed and the titanium alloy, Fe / Ti composite powder, and titanium alloy are tightly connected using a welding tool. A certain preload force is applied at the interface. The preferred preload force is 20-30 N.

[0044] (3) Laser welding is performed to completely melt the middle layer and partially melt the titanium alloy layers on both sides to form a weld.

[0045] In some embodiments, an imported FPLAS-1902 laser welding machine is used for welding, and the laser spot is irradiated vertically on the center line of the composite powder to completely melt the middle layer and partially melt the titanium alloy layers on both sides to form a weld.

[0046] In some embodiments, the laser power is 500-800 W, the laser control current is 60-80 A, the laser pulse width is 15-30 ms, the pulse frequency is 6-10 Hz, the defocus amount is +5 mm, the number of welding times is 1-3 times, the welding speed is 500-1500 mm / min, and the spot diameter is 1 mm.

[0047] The laser welding process makes the titanium alloy interface tightly connected, the structure is mainly composed of β phase and some Fe-Ti solid solution, and the alloy strength remains consistent with the parent material.

[0048] (4) Heat the weldment to T m The temperature is kept warm and then cooled. m The temperature is 500~600℃. Fire eliminates internal stress and makes the weld area uniform.

[0049] In some embodiments, the temperature is maintained for about 2 to 8 hours, and then the furnace is cooled to room temperature.

[0050] The present invention is applicable to Ti60 high-temperature titanium alloy, Ti65 high-temperature titanium alloy, Ti175 high-temperature titanium alloy and the like.

[0051] The present invention introduces a titanium film on the surface of the iron powder through a vibrating magnetron sputtering process, and then uses the composite powder as an intermediate layer for laser welding to improve the interface bonding. Iron, as a β-phase stabilizing element, can expand the β-phase region of the titanium alloy and reduce the β / α temperature. The Fe-Ti solid solution formed in the weld zone can also refine the β-phase grain size in the weld zone, improve the mechanical properties of the weld, and iron can reduce the viscosity of the molten pool, reduce the superheat of the molten pool metal, reduce the amount of metal vapor generated, and thus reduce the generation of pores, reduce laser welding defects, and improve the weldability of the titanium alloy. Through this process, the welding process is stable, the weld is beautiful, the heat-affected zone is small, there are no cracks, pores, or undercuts, and no penetration defects occur. In addition, this process has a fast welding speed and a narrow heat-affected zone, and can be used on a large scale.

[0052] Example 1:

[0053] The materials used in this implementation are Ti60 high temperature titanium alloy, nominal composition is .

[0054] Step 1) The iron powder was ultrasonically cleaned with acetone, deionized water, and anhydrous ethanol in sequence, and then dried in a vacuum oven at 60°C. The Ti60 block was scrubbed clean with acetone and anhydrous ethanol;

[0055] Step 2) Using a high-purity titanium target, magnetron sputtering was performed on the iron powder (using a VTC-16-PW small powder PVD sputtering apparatus with vibration), with a sputtering pressure of 8 Pa, a sputtering current of 80 mA, three depositions, a vibration motor speed of 400 rpm, and a single vibration time of 11 minutes, to obtain an Fe / Ti composite powder. The Ti film accounted for approximately 5% of the total mass of the Fe / Ti composite powder.

[0056] Step 3) Fix the pickled and polished Ti60 high-temperature titanium alloy on a workbench. The weld joint is an I-type groove butt weld with a butt assembly gap of 0.3 mm for placing Fe / Ti composite powder.

[0057] Step 4) Tighten the fixture to ensure that the titanium alloy-composite powder-titanium alloy contact surface is tightly connected, with a preload of 20-30N;

[0058] Step 5) Place the laser beam at the center line of the composite powder middle layer to completely melt the middle layer and partially melt the titanium alloy layers on both sides to form a weld. The laser power is 500 W, the laser control current is 80 A, the laser pulse width is 15 ms, the pulse frequency is 6 Hz, the defocus is +5 mm, the number of welds is 1, the welding speed is 500 mm / min, and the spot diameter is 1 mm.

[0059] Step 6) Heat the welded parts to 500°C and keep them at this temperature for 2 hours, then cool them to room temperature in the furnace.

[0060] Figure 2 These are the powder morphologies before and after vibration magnetron sputtering in Example 1. Figure a shows the morphology before sputtering, and Figure b shows the morphology after sputtering. After sputtering, a layer of nanoscale Ti film is attached to the surface of the Fe powder.

[0061] Figure 3 This is the line scanning analysis diagram and energy spectrum distribution diagram of the weld area in Example 1. The grain size in the heat affected zone (HAZ) is small, the grain size in the weld zone (WZ) is large, and other elements have no obvious diffusion behavior. The Fe element is enriched in the weld zone and there is obvious diffusion phenomenon. The diffusion area is about 430μm.

[0062] The mechanical properties of the welded workpiece were tested. The tensile area, including the weld area, showed a tensile strength of 954.1 MPa, a yield strength of 842.6 MPa, and an elongation of 8.46%, demonstrating excellent comprehensive mechanical properties.

[0063] Example 2:

[0064] The materials used in this implementation are Ti65 high temperature titanium alloy, the nominal composition is .

[0065] Step 1) The iron powder was ultrasonically cleaned with acetone, deionized water, and anhydrous ethanol in sequence, and then dried in a vacuum oven at 65°C. The Ti65 block was scrubbed clean with acetone and anhydrous ethanol;

[0066] Step 2) Using a high-purity titanium target, magnetron sputtering was performed on the iron powder (using a VTC-16-PW small powder PVD sputtering apparatus with vibration), with a sputtering pressure of 12 Pa, a sputtering current of 75 mA, four depositions, a vibration motor speed of 470 rpm, and a single vibration time of 12 minutes, to obtain an Fe / Ti composite powder. The Ti film accounted for approximately 5% of the total mass of the Fe / Ti composite powder.

[0067] Step 3) Fix the pickled and polished Ti65 high-temperature titanium alloy on a workbench. The weld joint is an I-type groove butt weld with a butt assembly gap of 0.25 mm for placing Fe / Ti composite powder.

[0068] Step 4) Tighten the fixture to ensure that the titanium alloy-composite powder-titanium alloy contact surface is tightly connected, with a preload of 20-30N;

[0069] Step 5) Place the laser beam at the center line of the composite powder middle layer to completely melt the middle layer and partially melt the titanium alloy layers on both sides to form a weld. The laser power is 600 W, the laser control current is 75 A, the laser pulse width is 18 ms, the pulse frequency is 8 Hz, the defocus is +5 mm, the number of welds is 2, the welding speed is 700 mm / min, and the spot diameter is 1 mm.

[0070] Step 6) Heat the welded parts to 500°C and keep them at this temperature for 4 hours, then cool them to room temperature in the furnace.

[0071] Figure 4 This is the line scanning analysis diagram and energy spectrum distribution diagram of the weld area in Example 2. The grain size in the heat affected zone (HAZ) is small, the grain size in the weld zone (WZ) is large, and other elements have no obvious diffusion behavior. The Fe element is enriched in the weld zone and there is obvious diffusion phenomenon. The diffusion area is about 390μm.

[0072] The mechanical properties of the welded workpiece were tested. The tensile area, including the weld area, showed a tensile strength of 965.3 MPa, a yield strength of 854.8 MPa, and an elongation of 7.65%, demonstrating excellent comprehensive mechanical properties.

[0073] Example 3:

[0074] The materials used in this implementation are Ti175 high temperature titanium alloy (Ti175 alloy has lower mechanical properties but higher plasticity), the nominal composition is .

[0075] Step 1) The iron powder was ultrasonically cleaned with acetone, deionized water, and anhydrous ethanol in sequence, and then dried in a vacuum oven at 60°C. The Ti175 block was scrubbed clean with acetone and anhydrous ethanol;

[0076] Step 2) Using a high-purity titanium target, magnetron sputtering is performed on the iron powder (using a VTC-16-PW small powder PVD sputtering instrument with vibration), with a sputtering gas pressure of 15 Pa, a sputtering current of 60 mA, 5 deposition times, a vibration motor speed of 500 r / min, and a single vibration time of 10 minutes, to obtain an Fe / Ti composite powder, in which the Ti film accounts for approximately 5% of the total mass of the Fe / Ti composite powder;

[0077] Step 3) The pickled and polished Ti175 high-temperature titanium alloy is fixed on a workbench. The weld joint is an I-type groove butt joint with a butt assembly gap of 0.2 mm for placing Fe / Ti composite powder.

[0078] Step 4) Tighten the fixture to ensure that the titanium alloy-composite powder-titanium alloy contact surface is tightly connected, with a preload of 20-30N;

[0079] Step 5) Place the laser beam at the center line of the composite powder middle layer to completely melt the middle layer and partially melt the titanium alloy layers on both sides to form a weld. The laser power is 700 W, the laser control current is 70 A, the laser pulse width is 25 ms, the pulse frequency is 9 Hz, the defocus is +5 mm, the number of welds is 2, the welding speed is 1000 mm / min, and the spot diameter is 1 mm.

[0080] Step 6) Heat the welded parts to 600°C and keep them at this temperature for 6 hours, then cool them to room temperature in the furnace.

[0081] Figure 5 This is the line scanning analysis diagram and energy spectrum distribution diagram of the weld area in Example 3. The grain size of the heat affected zone (HAZ) is small, the grain size of the weld zone (WZ) is large, and other elements have no obvious diffusion behavior. The Fe element is enriched in the weld zone and there is obvious diffusion phenomenon. The diffusion area is about 340μm.

[0082] The mechanical properties of the welded workpiece were tested. The tensile area, including the weld area, showed a tensile strength of 854.3 MPa, a yield strength of 765.2 MPa, and an elongation of 11.6%, demonstrating excellent comprehensive mechanical properties.

[0083] Example 4:

[0084] The materials used in this implementation are Ti60 and Ti65 titanium alloys, among which Ti60 alloy is Near α titanium alloy, Ti65 alloy Components are close to α titanium alloy.

[0085] Step 1) Ultrasonic cleaning of iron powder with acetone, deionized water, and anhydrous ethanol in sequence, followed by drying in a vacuum oven at 60°C. Ti60 and Ti65 blocks are scrubbed clean with acetone and anhydrous ethanol.

[0086] Step 2) Using a high-purity titanium target, magnetron sputtering is performed on the iron powder (using a magnetron sputtering device with vibration, VTC-16-PW small powder PVD sputtering instrument), with a sputtering gas pressure of 20 Pa, a sputtering current of 60 mA, a deposition number of 6 times, a vibration motor speed of 600 r / min, and a single vibration time of 15 minutes, to obtain an Fe / Ti composite powder. The Ti film accounts for approximately 5% of the total mass of the Fe / Ti composite powder;

[0087] Step 3) The pickled and polished Ti60 and Ti65 titanium alloys are fixed on a workbench respectively. The weld joints are I-groove butt welds with a butt assembly gap of 0.1 mm for placing composite powder.

[0088] Step 4) Tighten the fixture to ensure that the titanium alloy-composite powder-titanium alloy contact surface is tightly connected, with a preload of 20-30N;

[0089] Step 5) Place the laser beam at the center line of the composite powder middle layer to completely melt the middle layer and partially melt the titanium alloy layers on both sides to form a weld. The laser power is 800 W, the laser control current is 60 A, the laser pulse width is 30 ms, the pulse frequency is 10 Hz, the defocus is +5 mm, the number of welds is 3, the welding speed is 1500 mm / min, and the spot diameter is 1 mm.

[0090] Step 6) Heat the welded parts to 550°C and keep them at this temperature for 8 hours, then cool them to room temperature in the furnace.

[0091] Figure 6 This is the line scanning analysis diagram and energy spectrum distribution diagram of the weld area in Example 4. The grain size in the heat affected zone (HAZ) is small, the grain size in the weld zone (WZ) is large, and other elements have no obvious diffusion behavior. The Fe element is enriched in the weld zone and there is obvious diffusion phenomenon. The diffusion area is about 230μm.

[0092] The mechanical properties of the welded workpiece were tested. The tensile area, including the weld area, showed a tensile strength of 934.2 MPa, a yield strength of 825.4 MPa, and an elongation of 7.32%, demonstrating excellent comprehensive mechanical properties.

[0093] Comparative Example 1:

[0094] The difference between Comparative Example 1 and Example 1 is that no intermediate layer is introduced and welding is performed directly.

[0095] The weld area of ​​the welded workpiece had undercut and welding deformation defects. The mechanical properties of the workpiece were tested and the tensile strength was 634.2MPa, the yield strength was 525.4MPa, the elongation was 4.32%, and there were obvious pores on the tensile fracture, indicating poor mechanical properties.

[0096] Comparative Example 2:

[0097] The difference between Comparative Example 2 and Example 1 is that pure iron powder (without magnetron sputtering) is used to replace the Fe / Ti composite powder as the intermediate layer.

[0098] The welding effect of the weld zone of the welded workpiece is good, and no defects such as undercut, deformation, and pores are found. The mechanical properties of the workpiece are tested, and the tensile strength is 907.6MPa, the yield strength is 792.5MPa, and the elongation reaches 8.24%. The mechanical properties are lower than those of the Fe / Ti composite powder intermediate layer workpiece.

[0099] Comparative Example 3:

[0100] Comparative Example 2 differs from Example 1 in that: instead of using magnetron sputtering to prepare the Fe / Ti composite powder, iron powder and titanium powder with a mass ratio of 95:5 are ball-milled and uniformly mixed to form the intermediate layer.

[0101] The welding effect of the workpiece weld area is good, and no defects such as undercut, deformation, and pores are found. The mechanical properties of the workpiece are tested, and the tensile strength is 904.7MPa, the yield strength is 786.5MPa, and the elongation reaches 8.87%. The performance of Comparative Example 3 is close to that of Comparative Example 2, with better plasticity and lower mechanical properties than the Fe / Ti composite powder intermediate layer workpiece.

[0102] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any form. Therefore, any simple modifications, equivalent variations, and modifications to the above embodiments that do not depart from the technical solution of the present invention and are based on the technical essence of the present invention shall fall within the scope of protection of the technical solution of the present invention.

Claims

1. A high-temperature titanium alloy laser welding process, characterized in that: The steps include: (1) forming a titanium film layer on the surface of the iron powder by magnetron sputtering technology to wrap the iron powder particles, thereby obtaining Fe / Ti composite powder; in the Fe / Ti composite powder, the Ti film accounts for 4.5-5.5% of the total mass of the Fe / Ti composite powder; (2) Place Fe / Ti composite powder in the gap of the high-temperature titanium alloy to be welded to form an intermediate layer, and ensure that the titanium alloy-Fe / Ti composite powder-titanium alloy is tightly connected; (3) Laser welding is performed to completely melt the middle layer and partially melt the titanium alloy layers on both sides to form a weld; (4) Heat the weldment to 500~600℃ and keep it warm, then cool it.

2. The high-temperature titanium alloy laser welding process according to claim 1, characterized in that: The iron powder size in step (1) is controlled to be 150-250 μm.

3. The high temperature titanium alloy laser welding process according to claim 1 or 2, characterized in that: Step (1) uses a magnetron sputtering device with a vibration function.

4. The high temperature titanium alloy laser welding process according to claim 3, characterized in that: The target material used for magnetron sputtering in step (1) is high-purity titanium, the sputtering gas is argon, the sputtering pressure is 8~20Pa, and the sputtering current is 60~80mA.

5. The high temperature titanium alloy laser welding process according to claim 3, characterized in that: In step (1), the vibration motor speed of the magnetron sputtering equipment is 400-600 r / min, the deposition times are 3-6 times, and the vibration motor works for 10-15 minutes each time.

6. The high temperature titanium alloy laser welding process according to claim 1 or 2, characterized in that: In step (2), the assembly gap of the titanium alloy to be welded is 0.1~0.3mm.

7. The high temperature titanium alloy laser welding process according to claim 6, characterized in that: In step (2), the preload force at the titanium alloy-Fe / Ti composite powder-titanium alloy interface is controlled at 20-30N.

8. The high temperature titanium alloy laser welding process according to claim 1 or 2, characterized in that: In step (3), the laser power of laser welding is 500-800 W, the laser control current is 60-80 A, the laser pulse frequency is 6-10 Hz, and the welding speed is 500-1500 mm / min.

9. The high temperature titanium alloy laser welding process according to claim 1 or 2, characterized in that: Step (4) Keep warm for 2 to 8 hours.

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