Laser deposition and linear rolling manufacturing method for ti 2alnb alloy, and integrated device

Abstract

The present invention provides a laser deposition and linear rolling manufacturing method for a Ti2AlNb alloy, and an integrated device. The manufacturing method comprises the steps of: reducing the oxygen content of a box assembly to 50 PPm or less; by taking the spherical rotating electrode powder as a raw material, using a laser deposition assembly to manufacture, on a Ti-6Al-4V rolling substrate and according to a preset trajectory, a deposition layer having a columnar crystal structure; using a press assembly to perform linear rolling on the deposition layer, so as to obtain a deformed deposition layer having a columnar crystal structure; and then using the laser deposition assembly to continuously manufacture a single deposition layer on the deformed deposition layer having a columnar crystal structure to obtain a deposition layer having an isometric crystal structure; and repeating the steps until the Ti2AlNb alloy has the specified size. The integrated device comprises a box assembly, a laser deposition assembly, a laser rangefinder assembly, a press assembly, and a workbench assembly. According to the present invention, static recrystallization is induced by laser high-energy thermal cycle, and the transformation of thick epitaxial columnar crystals into uniform and fine isometric crystals is implemented, so that the comprehensive mechanical property of the Ti2AlNb alloy is improved.

Description

Laser deposition and linear rolling manufacturing method and integrated device for Ti2AlNb alloy Technical Field

[0001] The present invention relates to the technical field of material preparation, and in particular to a laser deposition and linear rolling manufacturing method and an integrated device for Ti2AlNb alloy. Background Art

[0002] Ti2AlNb-based intermetallic alloys combine the properties of metals and ceramics, making them lightweight, high-temperature resistant structural materials. They can operate for long periods at temperatures between 650°C and 750°C. Compared to γ-TiAl alloys, they exhibit higher room-temperature ductility, fracture toughness, and crack growth resistance. Compared to the nickel-based superalloy GH4169, they also possess higher specific strength, making them suitable for manufacturing key components such as compressor disks, blisks, and casings in aircraft engines.

[0003] The physical properties of the various elements in Ti2AlNb alloy vary greatly, and the solid-liquid two-phase region is relatively wide. Traditional melt-casting methods face problems such as severe segregation, solidification shrinkage pores, and coarse grains, requiring subsequent homogenization annealing and multiple passes of thermomechanical processing to refine the grains. Traditional casting-forging processes can produce high-performance Ti2AlNb alloy billets, but the high manufacturing costs and long production cycles limit the application of thermomechanical processing in large-scale complex structural parts. Powder metallurgy can effectively improve problems such as macro-element segregation and microstructural inhomogeneity, breaking through the limitations of ingot size and the tonnage of hot deformation equipment, but expensive molds are still required to produce complex-shaped workpieces.

[0004] Additive manufacturing technology utilizes a high-density energy beam to melt and solidify raw materials layer by layer. Through precise computer control, it can produce complex three-dimensional components, effectively addressing the high deformation resistance and severe macrosegregation issues of Ti2AlNb-based alloys. However, the inherent high temperature gradient of the additive manufacturing process inhibits the nucleation of new grains during the rapid solidification process, resulting in poor mechanical properties and significant anisotropy, making it difficult to meet practical engineering requirements.

[0005] Typically, titanium's dense oxide film protects it at room temperature. However, when molten, it cannot be protected by this oxide film and can spontaneously combust or even explode in air. Powdered, dusty, or finely shaving titanium can easily ignite with a small spark. Therefore, melt processing of titanium alloys for additive manufacturing requires a low-oxygen environment. Summary of the Invention

[0006] In response to the problems existing in the prior art, the present invention provides a laser deposition and linear rolling manufacturing method and integrated device for Ti2AlNb alloy. In a low-oxygen environment provided by a highly sealed inert atmosphere box, by combining laser deposition of the laser deposition component with linear rolling of the press component, the buffer layer provided by the internal ductile high-temperature B2 phase in the laser heat-affected zone and the natural sheathing of the three-dimensional compressive stress structure of the linear rolling are utilized. This solves the problem of Ti2AlNb alloy being prone to cracking during deformation, making linear rolling of Ti2AlNb alloy feasible. At the same time, linear rolling significantly reduces the deformation resistance of Ti2AlNb alloy, so that static recrystallization can be induced by subsequent laser high-energy thermal cycles, thereby directly processing fine-grained equiaxed Ti2AlNb alloy, and achieving direct additive manufacturing of Ti2AlNb alloy without the need for heavy equipment and extreme deformation and high temperatures.

[0007] The present invention provides a laser deposition and linear rolling method for manufacturing Ti2AlNb alloy, comprising the following steps:

[0008] S1. The Ti-6Al-4V rolled substrate was polished with SiC abrasive and cleaned with acetone. Meanwhile, the spherical rotating electrode powder was dried in a vacuum environment at 120°C for 2 hours.

[0009] S2. The cleaned Ti-6Al-4V rolled substrate is mounted in a box assembly, and an argon gas flow is used to reduce the oxygen content of the box assembly to below 50 ppm, thereby preventing the formation of a loose oxide film;

[0010] S3, using a laser deposition assembly equipped with a three-way coaxial powder feeding laser head, using dried spherical rotating electrode powder as raw material, to produce a deposition layer with a columnar crystal structure of a certain height on a cleaned Ti-6Al-4V rolled substrate according to a preset trajectory;

[0011] S4. After the deposited layer obtained in step S3 is cooled for a period of time, the deposited layer is linearly rolled using a press assembly equipped with a detachable pressing head. The linear rolling provides deformation and distortion energy, thereby obtaining a deposited layer having a deformed columnar crystal structure.

[0012] S41, moving the detachable pressing head to above the starting point of the deposition layer obtained in step S3, continuously lowering the detachable pressing head, and reading the value of the extrusion force between the detachable pressing head and the deposition layer through the pressure sensor;

[0013] S42. When the extrusion force obtained in step S41 exceeds the elastic limit of the material, a low extrusion feed rate V is used to apply plastic deformation to the deposited layer. After the plastic deformation reaches a preset reduction amount, the indenter moves according to a set motion trajectory, and the spherical roller at the tip of the indenter rolls as the indenter moves. After the linear rolling is completed, a deposited layer with a deformed columnar crystal structure is obtained. The expression of the extrusion force is:

[0014] F=σ e × s

[0015] Among them, σ e is the elastic limit of the material, s is the area of ​​the detachable indenter;

[0016] S5. On the deposited layer having the deformed columnar crystal structure obtained in step S4, a laser deposition assembly equipped with a laser head having three coaxial powder feeders is used to continue to produce a single deposited layer along a preset trajectory using the dried spherical rotating electrode powder as a raw material, thereby obtaining a deposited layer having an equiaxed crystal structure.

[0017] S6. Adjust the laser head in the laser deposition assembly according to the preset single-layer thickness of laser deposition-line rolling, and repeat steps S4 and S5 until the Ti2AlNb alloy reaches a specified size.

[0018] Preferably, in step S1 , the particle size of the spherical rotating electrode powder is 40-130 μm, and the composition of the spherical rotating electrode powder is Ti-22Al-25Nb.

[0019] Preferably, in step S2, the process parameters of the laser deposition assembly are: the power of the laser head is 1400~1800W, the scanning rate of the laser head is 6~10mm / s, the spot diameter of the laser head is 3mm, the overlap rate of the laser head is 30%, and the powder feeding rate of the laser head is 4g / min.

[0020] Preferably, in step S4, the cooling time of the deposited layer is 30 to 60 seconds.

[0021] Preferably, in step S4, the process parameters of the press assembly are: the press head width of the press is 3~3.5mm, the pressing amount of the press is 0.15~0.35mm, the rolling rate of the press is 0.2mm / s, and the overlap rate of the press is 30%.

[0022] Preferably, in step S6, the thickness of a single layer of the laser deposition-line rolling is 0.5-0.6 mm.

[0023] Another aspect of the present invention provides an integrated device for the laser deposition and linear rolling method for manufacturing Ti2AlNb alloys. The device comprises a laser deposition assembly, a laser rangefinder assembly, a press assembly, and a workbench assembly, each of which is located within a housing assembly. The laser deposition assembly comprises a laser head, a laser head displacement slider, and a laser head base. The first end of the laser head base is connected to the first mounting end of the bottom of the housing. The second end of the laser head base is connected to the first end of the laser head displacement slider via a lead screw guide assembly. The second end of the laser head displacement slider is equipped with a laser head. The laser rangefinder assembly comprises a laser rangefinder, a laser rangefinder displacement slider, and a laser rangefinder base. The first end of the laser rangefinder base is connected to the second mounting end of the bottom of the housing. The second end of the laser rangefinder base is connected to the first end of the laser rangefinder displacement slider via a lead screw guide assembly. The second end of the laser rangefinder displacement slider is equipped with a laser rangefinder. The press assembly includes a detachable ram, a press displacement slider, and a press base. The first end of the press base is connected to the third mounting end at the bottom of the housing. The second end of the press base is connected to the first end of the press displacement slider via a screw guide assembly. The second end of the press displacement slider is provided with a detachable ram. The workbench assembly includes a workbench, an X-axis displacement guide seat, a Y-axis displacement slider, a Y-axis displacement guide seat, and an X-axis displacement slider. The first end of the Y-axis displacement guide seat is connected to the fourth mounting end at the bottom of the housing. The second end of the Y-axis displacement guide seat is connected to the first end of the Y-axis displacement slider via a screw guide assembly. The second end of the Y-axis displacement slider is connected to the first end of the X-axis displacement guide seat. The second end of the X-axis displacement guide seat is connected to the first end of the X-axis displacement slider via a screw guide assembly. The second end of the X-axis displacement slider is connected to the workbench. The workbench is provided with a threaded hole for fixing the workpiece to be processed. The third end of the X-axis displacement guide seat is provided with a protective cover.

[0024] Preferably, it also includes a box body assembly, which includes an outer shell, an upper cover, a fixed cover, a box door and an observation window, the upper end of the outer shell is connected to the first end of the upper cover, the second end of the upper cover is connected to the first end of the fixed cover through a fixed cover sealing gasket, the second end of the fixed cover is provided with a gas-liquid quick connector, the front end of the outer shell is respectively connected to the left box door and the right box door through positioning pins, the mounting ends of the left box door and the right box door are respectively provided with box door sealing gaskets, the left end and the right end of the outer shell are respectively symmetrically provided with a left observation window and a right observation window, the mounting ends of the left observation window and the right observation window are respectively provided with observation window sealing gaskets, the first side end and the second side end of the outer shell are respectively provided with a pressure relief valve and an inert gas inlet.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] 1. The manufacturing method of the present invention combines laser deposition with linear rolling, utilizing the buffer layer provided by the internal ductile high-temperature B2 phase in the laser heat-affected zone and the natural sheath of the three-dimensional compressive stress structure of linear rolling to effectively prevent the highly intrinsic brittle Ti2AlNb alloy from cracking during deformation.

[0027] 2. The manufacturing method of the present invention uses linear rolling to reduce deformation resistance and realize small deformation processing in the composite additive manufacturing process, which is beneficial to eliminate the preferential orientation of materials and corresponding components, refine the organizational structure of materials and corresponding components, and improve the mechanical properties of materials and corresponding components.

[0028] 3. The manufacturing method of the present invention uses laser high-energy thermal cycling to induce static recrystallization, breaking the coarse epitaxial columnar crystals into uniform and fine equiaxed crystals, thereby improving the comprehensive mechanical properties of the material.

[0029] 4. The integrated device of the present invention integrates the laser deposition component, the press component and the laser rangefinder component, avoiding the tedious operation of transferring between devices and improving the efficiency of workpiece processing. The laser rangefinder component realizes the monitoring of the status of the workpiece to be processed, which strengthens the processing control of the workpiece to be processed to a certain extent; at the same time, the highly sealed inert atmosphere box is used to provide a low oxygen content environment, thereby realizing the processing of easily oxidized materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] FIG1 is a diagram showing the overall structure of an integrated device for the laser deposition and linear rolling method for manufacturing Ti2AlNb alloy according to the present invention;

[0031] FIG2 is an exploded view of an integrated device for the laser deposition and wire rolling method for manufacturing Ti2AlNb alloy according to the present invention;

[0032] FIG3 is a top view of the integrated device for the laser deposition and wire rolling method for manufacturing Ti2AlNb alloy according to the present invention, with the upper cover plate removed;

[0033] FIG4 is a structural diagram of a laser deposition assembly in an integrated device for laser deposition and linear rolling manufacturing of Ti2AlNb alloy according to the present invention;

[0034] FIG5 is a structural diagram of a laser ranging assembly in an integrated device for the laser deposition and linear rolling method for manufacturing Ti2AlNb alloy according to the present invention;

[0035] FIG6 is a structural diagram of a press assembly in an integrated device for the laser deposition and wire rolling method for manufacturing Ti2AlNb alloy according to the present invention;

[0036] FIG7 is a schematic diagram of a detachable indenter in an integrated device for the laser deposition and wire rolling method for manufacturing Ti2AlNb alloy according to the present invention;

[0037] FIG8 is a structural diagram of a workbench assembly in an integrated device for laser deposition and linear rolling manufacturing of Ti2AlNb alloy according to the present invention;

[0038] FIG9 is a cross-sectional view of an integrated device for the laser deposition and wire rolling manufacturing method of Ti2AlNb alloy according to the present invention;

[0039] FIG10 is a flow chart of the laser deposition and wire rolling method for manufacturing Ti2AlNb alloy according to the present invention;

[0040] FIG11a shows a deposited layer having a columnar crystal structure after a single laser deposition in the laser deposition and wire rolling method for manufacturing Ti2AlNb alloy according to the present invention;

[0041] FIG11b is a deposition layer having a deformed columnar crystal structure after linear rolling in the laser deposition and linear rolling method for manufacturing Ti2AlNb alloy according to the present invention;

[0042] FIG11c is a deposition layer having an equiaxed crystal structure after secondary laser deposition in the laser deposition and wire rolling method for manufacturing Ti2AlNb alloy according to the present invention;

[0043] FIG12 is a macroscopic optical microstructure diagram of a Ti2AlNb workpiece in the method for manufacturing a Ti2AlNb alloy according to the present invention;

[0044] FIG13 is an optical microstructure diagram of the single-phase region at the top of a Ti2AlNb workpiece in the method for manufacturing a Ti2AlNb alloy according to the present invention;

[0045] FIG14 is an optical microstructure diagram of the three-phase region at the bottom of the Ti2AlNb workpiece in the method for manufacturing Ti2AlNb alloy according to the present invention.

[0046] Main reference numerals:

[0047] Box body assembly 1, outer shell 11, locating pin 111, box door gasket 112, observation window gasket 113, pressure relief valve 114, inert gas inlet 115, upper cover 12, fixed cover gasket 121, fixed cover 13, gas-liquid quick connector 131, left box door 14, right box door 15, right observation window 16, left observation window 17, laser deposition assembly 2, laser head 21, laser head displacement slider 22, laser head base 23, laser rangefinder assembly 3, laser rangefinder 31, laser rangefinder displacement slider 32, laser rangefinder base 33, press assembly 4, detachable press head 41, press displacement slider 42, press base 43, workbench assembly 5, workbench 51, protective cover 52, X-axis displacement guide rail seat 53, Y-axis displacement slider 54, Y-axis displacement guide rail seat 55, X-axis displacement slider 56, workpiece to be processed 6. DETAILED DESCRIPTION

[0048] To fully describe the technical content, structural features, objectives and effects of the present invention, the following is a detailed description with reference to the accompanying drawings.

[0049] Based on the characteristics of high performance of thermomechanical processing and additive manufacturing, the present invention proposes a laser deposition and wire rolling manufacturing method for titanium aluminum alloy, specifically for Ti2AlNb alloy, as shown in Figure 10. The specific implementation steps are as follows:

[0050] S1. The Ti-6Al-4V rolled substrate was polished with SiC abrasive and cleaned with acetone. At the same time, the spherical rotating electrode powder was dried in a vacuum environment at 120°C for 2 hours.

[0051] Specifically, the particle size of the spherical rotating electrode powder is 40-130 μm, and the composition of the spherical rotating electrode powder is Ti-22Al-25Nb.

[0052] S2. Install the cleaned Ti-6Al-4V rolled substrate into the housing assembly 1. At room temperature, titanium reacts with oxygen to form a dense oxide film that prevents further diffusion of oxygen into the substrate. However, when heated above 500°C, the titanium oxide film becomes loose and easily peels off, and may even become hard and brittle. Therefore, a low-oxygen environment is required during the laser deposition of the Ti2AlNb alloy to prevent the formation of a loose oxide film on the Ti2AlNb alloy at high temperatures. Therefore, an argon gas flow is used to reduce the oxygen content of the housing assembly 1 to below 50 ppm, thereby preventing the formation of a loose oxide film. The argon gas flow rate is 10 L / min.

[0053] S3. Due to the defect that the bypass powder feeding can only move in a linear trajectory along the direction of the powder feeding tube, a laser deposition assembly 2 equipped with a laser head 21 with three-way coaxial powder feeding is used to use the dried spherical rotating electrode powder as raw material to manufacture a deposition layer with a columnar crystal structure of a certain height on the cleaned Ti-6Al-4V rolled substrate according to a preset trajectory. The moving trajectory of the laser deposition assembly 2 does not need to be linear, which provides feasibility for the manufacture of complex-shaped workpieces and various nonlinear path scanning methods.

[0054] Specifically, the process parameters of the laser deposition component 2 are: the power of the laser head 21 is 1400~1800W, the scanning rate of the laser head 21 is 6~10mm / s, the spot diameter of the laser head 21 is 3mm, the overlap rate of the laser head 21 is 30%, and the powder feeding rate of the laser head 21 is 4g / min.

[0055] S4. After cooling the deposited layer obtained in step S3 for 30 to 60 seconds, the deposited layer is subjected to linear rolling using a press assembly 4 equipped with a detachable pressing head 41. The linear rolling provides deformation and distortion energy, thereby obtaining a deposited layer having a deformed columnar crystal structure.

[0056] S41, moving the detachable pressing head to above the starting point of the deposition layer obtained in step S3, continuously lowering the detachable pressing head, and reading the value of the extrusion force between the detachable pressing head and the deposition layer through the pressure sensor.

[0057] S42. When the extrusion force obtained in step S41 exceeds the elastic limit of the material, a low extrusion feed rate V is used to apply plastic deformation to the deposited layer. After the plastic deformation reaches a preset reduction amount, the indenter moves according to the set motion trajectory, and the spherical roller at the tip of the indenter rolls as the indenter moves. After the linear rolling is completed, a deposited layer with a deformed columnar crystal structure is obtained. The expression of the extrusion force is:

[0058] F=σ e × s

[0059] Among them, σ e is the elastic limit of the material, and s is the area of ​​the detachable pressing head 41.

[0060] Specifically, the process parameters of the press assembly 4 are: the press head width of the press is 3~3.5mm, the pressing amount of the press is 0.15~0.35mm, the rolling rate of the press is 0.2mm / s, and the overlap rate of the press is 30%.

[0061] Preferably, the detachable pressure head 41 is a spherical pressure head. The detachable design facilitates maintenance and replacement of the pressure head after wear. The spherical roller at the tip of the spherical pressure head can self-lubricate and roll on the working plane as the pressure head moves, thereby realizing linear rolling on the workpiece. The specific appearance structure is shown in Figure 7.

[0062] S5. On the deposition layer of deformed columnar crystal structure obtained in step S4, a laser deposition assembly 2 equipped with a three-way coaxial powder feeding laser head 21 is used to use the dried spherical rotating electrode powder as raw material to continue to manufacture a single-layer deposition layer according to a preset trajectory. The thermal effect of the laser molten pool of the laser deposition assembly 2 is utilized to cause the deposition structure to undergo static recrystallization and transform into an equiaxed crystal structure, thereby obtaining a deposition layer with an equiaxed crystal structure.

[0063] S6. Adjust the laser head 21 in the laser deposition assembly 2 according to the preset single layer thickness of 0.5-0.6 mm for laser deposition-line rolling, and repeat steps S4 and S5 until the Ti2AlNb alloy reaches the specified size.

[0064] An integrated device for laser deposition and linear rolling manufacturing of Ti2AlNb alloy, as shown in Figures 1 and 3, includes a rectangular and sealed box assembly 1, a laser deposition assembly 2, a laser rangefinder assembly 3, a press assembly 4 and a workbench assembly 5. The laser deposition assembly 2, the laser rangefinder assembly 3, the press assembly 4 and the workbench assembly 5 are respectively located inside the box assembly 1.

[0065] The box assembly 1, as shown in Figures 2 and 9, includes an outer shell 11, an upper cover 12, a fixed cover 13, a left box door 14, a right box door 15, a right observation window 16 and a left observation window 17. The outer shell 11 is formed by four box side panels and a lower bottom plate that are welded and sealed to each other. Box sealing grooves are processed between the upper cover 12, the left box door 14 and the right box door 15 and the outer shell 11, and box sealing gaskets are installed in the box sealing grooves to ensure sealing and are fastened by threads. The outer shell 11, the left door 14, the right door 15 and the upper cover 12 all have reinforcing ribs. The left door 14 and the right door 15 both include door frames, tempered glass and door handles. Reinforcing ribs are installed on the door frames to protect the tempered glass. The contact surface between the door frame and the door tempered glass is provided with a door glass sealing gasket. The left observation window 17 and the right observation window 16 both include an observation window outer frame and a tempered glass observation mirror. The tempered glass observation mirror is fastened to the observation window outer frame by bolts, and the observation window outer frame is fixedly connected to the left and right sides of the box shell 11 by bolts.

[0066] The upper end of the outer shell 11 is connected to the first end of the upper cover 12, and the second end of the upper cover 12 is connected to the first end of the fixed cover 13 through the fixed cover sealing gasket 121. The second end of the fixed cover 13 is provided with a gas-liquid quick connector 131 and a fiber optic connection hole extending from the upper end of the fiber optic connecting tube of the laser head 21 with three-axis synchronous powder feeding and high power. The gas-liquid quick connector 131 is composed of a powder feeding port quick connector, a powder air inlet quick connector, a laser air inlet quick connector, a cooling water inlet quick connector and a cooling water outlet quick connector. The fixed cover 13 is sealed at the fiber optic connection hole by a flange shaft seal, and the bottom of the flange shaft seal is fastened to the fixed cover 13 by bolts.

[0067] The front end of the shell 11 is connected to the left box door 14 and the right box door 15 through a positioning pin 111, and the positioning pin 111 is used for positioning during installation. The installation ends of the left box door 14 and the right box door 15 are respectively provided with a box door sealing gasket 112, and the left and right ends of the shell 11 are respectively symmetrically provided with a left observation window 17 and a right observation window 16, and the installation ends of the left observation window 17 and the right observation window 16 are respectively provided with an observation window sealing gasket 113. The first side end, the second side end, the third side end and the fourth side end of the shell 11 are respectively provided with a pressure relief valve 114 for balancing the air pressure in the box assembly 1, an inert gas inlet 115 for filling inert gas into the box assembly 1, an oxygen measuring port for detecting the oxygen content in the box assembly 1, and a power line and data line interface connected to various devices in the box assembly 1.

[0068] The laser deposition assembly 2, as shown in Figure 4, includes a laser head 21, a laser head displacement slider 22 and a laser head base 23. The first end of the laser head base 23 is connected to the first mounting end of the bottom of the housing 11 through a bolt, and the second end of the laser head base 23 is connected to the first end of the laser head displacement slider 22 through a screw guide assembly. The second end of the laser head displacement slider 22 is provided with a laser head 21, and the input end of the screw guide assembly is connected to the servo drive motor through a coupling.

[0069] The laser rangefinder assembly 3, as shown in Figure 5, includes a laser rangefinder 31, a laser rangefinder displacement slider 32 and a laser rangefinder base 33. The first end of the laser rangefinder base 33 is connected to the second mounting end of the bottom of the housing 11 through a bolt, and the second end of the laser rangefinder base 33 is connected to the first end of the laser rangefinder displacement slider 32 through a screw guide assembly. The second end of the laser rangefinder displacement slider 32 is provided with the laser rangefinder 31.

[0070] The press assembly 4, as shown in Figure 6, includes a detachable press head 41, a press displacement slider 42 and a press base 43. The first end of the press base 43 is connected to the third mounting end at the bottom of the housing 11 through a bolt, the second end of the press base 43 is connected to the first end of the press displacement slider 42 through a screw guide assembly, and the detachable press head 41 is connected to the second end of the press displacement slider 42 through a thread.

[0071] The workbench assembly 5, as shown in Figure 8, includes a workbench 51, a protective cover 52, an X-axis displacement guide seat 53, a Y-axis displacement slider 54, a Y-axis displacement guide seat 55 and an X-axis displacement slider 56. The first end of the Y-axis displacement guide seat 55 is connected to the fourth mounting end at the bottom of the housing 11 through a bolt, the second end of the Y-axis displacement guide seat 55 is connected to the first end of the Y-axis displacement slider 54 through a screw guide assembly, the second end of the Y-axis displacement slider 54 is connected to the first end of the X-axis displacement guide seat 53, the second end of the X-axis displacement guide seat 53 is connected to the first end of the X-axis displacement slider 56 through the screw guide assembly, the second end of the X-axis displacement slider 56 is connected to the workbench 51, the workbench 51 is provided with a threaded hole for fixing the workpiece 6 to be processed, and the third end of the X-axis displacement guide seat 53 is provided with a telescopic protective cover 52.

[0072] The following is a further description of a laser deposition and linear rolling method and integrated device for manufacturing Ti2AlNb alloy according to the present invention, in conjunction with embodiments:

[0073] In this specific embodiment, inert gas is first introduced into the box assembly 1 through the inert gas inlet 115, and the pressure relief valve 114 is opened to balance the box assembly 1 for purge, waiting for the oxygen content in the box assembly 1 to be lower than 50 ppm. Then, the melting stage is entered, and the workbench 51 is moved through the workbench assembly 5 to the bottom of the laser head 21. According to the set laser parameters and scanning mode, the laser head 21 in the laser deposition assembly 2 is used to deposit the workpiece 6 to be processed. After the deposition is completed, a cooling time of 30 seconds is waited. Then, the height measurement stage is entered, and the workbench 51 is moved through the workbench assembly 5 to the bottom of the laser rangefinder 31. The laser rangefinder 31 is used to measure the growth height of the workpiece 6 to be processed during the melting stage. Finally, the rolling stage is entered, and the workbench 51 is moved through the workbench assembly 5 to the bottom of the detachable pressing head 41. According to the set rolling parameters, the detachable pressing head 41 is used to linearly roll the workpiece 6 to be processed. After rolling is completed, the workbench assembly 5 moves the workbench 51 back to its initial position to start the next layer cycle. As shown in Figures 11a, 11b, and 11c, during linear rolling, the detachable indenter 41 plastically deforms the workpiece 6 at a speed v. Subsequently, during the reheating process of the laser head 21, the coarse columnar crystals are broken into fine equiaxed crystals through static recrystallization, thereby making equiaxed crystals the primary structural feature of the Ti2AlNb alloy workpiece, significantly improving the mechanical properties of the Ti2AlNb alloy workpiece. After the workpiece is manufactured, a metallographic sample is prepared and examined using an optical microscope. In Figure 12, the high-temperature region at the top of the workpiece in the macroscopic optical microstructure image is primarily composed of the B2 phase, while the bottom portion outside the high-temperature region is a precipitation region composed of precipitated phases. Furthermore, Figures 13 and 14 show metallographic images of the Ti2AlNb alloy workpiece with equiaxed crystals as the primary structural feature.

[0074] Example 1

[0075] S1. The Ti-6Al-4V rolled substrate was polished with SiC abrasive and cleaned with acetone. At the same time, the spherical rotating electrode powder was dried in a vacuum environment at 120°C for 2 hours.

[0076] S2. The cleaned Ti-6Al-4V rolled substrate is mounted in the box assembly 1. An argon flow is used to reduce the oxygen content of the box assembly 1 to below 50 ppm to prevent the formation of a loose oxide film. The flow rate of the argon flow is 10 L / min.

[0077] S3. Using a laser deposition assembly 2 equipped with a three-way coaxial powder feeding laser head 21, the dried spherical rotating electrode powder is used as raw material to produce a deposition layer with a columnar crystal structure of a certain height on the cleaned Ti-6Al-4V rolled substrate according to a preset trajectory.

[0078] Specifically, the process parameters of the laser deposition assembly 2 are: the power of the laser head 21 is 1800W, the scanning rate of the laser head 21 is 10mm / s, the spot diameter of the laser head 21 is 3mm, the overlap rate of the laser head 21 is 30%, and the powder feeding rate of the laser head 21 is 4g / min.

[0079] S4. After cooling the deposited layer obtained in step S3 for 30 seconds, the deposited layer is linearly rolled using a press assembly 4 equipped with a detachable pressing head 41 to obtain a deposited layer having a deformed columnar crystal structure.

[0080] Specifically, the process parameters of the press assembly 4 are: the width of the press head is 3 mm, the pressing amount of the press is 0.3 mm, the rolling rate of the press is 0.2 mm / s, and the overlap rate of the press is 30%.

[0081] S5. On the deposition layer of deformed columnar crystal structure obtained in step S4, a laser deposition assembly 2 equipped with a three-way coaxial powder feeding laser head 21 is used to use the dried spherical rotating electrode powder as raw material to continue to manufacture a single-layer deposition layer according to a preset trajectory. The thermal effect of the laser molten pool of the laser deposition assembly 2 is utilized to cause the deposition structure to undergo static recrystallization and transform into an equiaxed crystal structure, thereby obtaining a deposition layer with an equiaxed crystal structure.

[0082] S6. Adjust the laser head 21 in the laser deposition assembly 2 according to the preset single layer thickness of laser deposition-line rolling of 0.5~0.6mm, and repeat steps S4 and S5 until the Ti2AlNb alloy reaches the specified size to obtain Example 1.

[0083] The Ti2AlNb alloy obtained by the process method of the present invention in this embodiment has the advantages of near-net forming in additive manufacturing while also having the advantages of high thermomechanical processing microstructure performance. Direct additive manufacturing of the Ti2AlNb alloy can be achieved without the need for heavy equipment and extreme deformation and high temperature conditions.

[0084] Example 2

[0085] S1. The Ti-6Al-4V rolled substrate was polished with SiC abrasive and cleaned with acetone. At the same time, the spherical rotating electrode powder was dried in a vacuum environment at 120°C for 2 hours.

[0086] S2. The cleaned Ti-6Al-4V rolled substrate is mounted in the box assembly 1. An argon flow is used to reduce the oxygen content of the box assembly 1 to below 50 ppm to prevent the formation of a loose oxide film. The flow rate of the argon flow is 10 L / min.

[0087] S3. Using a laser deposition assembly 2 equipped with a three-way coaxial powder feeding laser head 21, the dried spherical rotating electrode powder is used as a raw material to produce a deposition layer of a certain height on the cleaned Ti-6Al-4V rolled substrate according to a preset trajectory.

[0088] Specifically, the process parameters of the laser deposition assembly 2 are: the power of the laser head 21 is 1800W, the scanning rate of the laser head 21 is 10mm / s, the spot diameter of the laser head 21 is 3mm, the overlap rate of the laser head 21 is 30%, and the powder feeding rate of the laser head 21 is 4g / min.

[0089] S4. After cooling the deposited layer obtained in step S3 for 30 seconds, the deposited layer is linearly rolled using a press assembly 4 equipped with a detachable pressing head 41 to obtain a deposited layer having a deformed columnar crystal structure.

[0090] Specifically, the process parameters of the press assembly 4 are: the width of the press head is 3 mm, the pressing amount of the press is 0.15 mm, the rolling rate of the press is 0.2 mm / s, and the overlap rate of the press is 30%.

[0091] S5. On the deposition layer of deformed columnar crystal structure obtained in step S4, a laser deposition assembly 2 equipped with a three-way coaxial powder feeding laser head 21 is used to use the dried spherical rotating electrode powder as raw material to continue to manufacture a single-layer deposition layer according to a preset trajectory. The thermal effect of the laser molten pool of the laser deposition assembly 2 is utilized to cause the deposition structure to undergo static recrystallization and transform into an equiaxed crystal structure, thereby obtaining a deposition layer with an equiaxed crystal structure.

[0092] S6. Adjust the laser head 21 in the laser deposition assembly 2 according to the preset single layer thickness of laser deposition-line rolling of 0.5~0.6mm, and repeat steps S4 and S5 until the Ti2AlNb alloy reaches the specified size to obtain Example 2.

[0093] The main microstructure characteristics of the Ti2AlNb alloy workpiece obtained by the process method of the present invention in this embodiment are all equiaxed crystals. No heavy equipment and extreme deformation and high temperature are required during the preparation process. The preparation process is simple and can greatly reduce the cost of manufacturing high-performance Ti2AlNb alloy.

[0094] Example 3

[0095] S1. The Ti-6Al-4V rolled substrate was polished with SiC abrasive and cleaned with acetone. At the same time, the spherical rotating electrode powder was dried in a vacuum environment at 120°C for 2 hours.

[0096] S2. The cleaned Ti-6Al-4V rolled substrate is mounted in the box assembly 1. An argon flow is used to reduce the oxygen content of the box assembly 1 to below 50 ppm to prevent the formation of a loose oxide film. The flow rate of the argon flow is 10 L / min.

[0097] S3. Using a laser deposition assembly 2 equipped with a three-way coaxial powder feeding laser head 21, the dried spherical rotating electrode powder is used as a raw material to produce a deposition layer of a certain height on the cleaned Ti-6Al-4V rolled substrate according to a preset trajectory.

[0098] Specifically, the process parameters of the laser deposition assembly 2 are: the power of the laser head 21 is 1800W, the scanning rate of the laser head 21 is 5mm / s, the spot diameter of the laser head 21 is 3mm, the overlap rate of the laser head 21 is 30%, and the powder feeding rate of the laser head 21 is 4g / min.

[0099] S4. After cooling the deposited layer obtained in step S3 for 30 seconds, the deposited layer is linearly rolled using a press assembly 4 equipped with a detachable pressing head 41 to obtain a deposited layer having a deformed columnar crystal structure.

[0100] Specifically, the process parameters of the press assembly 4 are: the width of the press head is 3 mm, the pressing amount of the press is 0.3 mm, the rolling rate of the press is 0.2 mm / s, and the overlap rate of the press is 30%.

[0101] S5. On the deposition layer of deformed columnar crystal structure obtained in step S4, a laser deposition assembly 2 equipped with a three-way coaxial powder feeding laser head 21 is used to use the dried spherical rotating electrode powder as raw material to continue to manufacture a single-layer deposition layer according to a preset trajectory. The thermal effect of the laser molten pool of the laser deposition assembly 2 is utilized to cause the deposition structure to undergo static recrystallization and transform into an equiaxed crystal structure, thereby obtaining a deposition layer with an equiaxed crystal structure.

[0102] S6. Adjust the laser head 21 in the laser deposition assembly 2 according to the preset single layer thickness of laser deposition-line rolling of 0.5~0.6mm, and repeat steps S4 and S5 until the Ti2AlNb alloy reaches the specified size to obtain Example 3.

[0103] In this embodiment, laser deposition and linear rolling are performed alternately through the process method of the present invention, so that the plastic deformation area is covered by the heat-affected zone generated during reheating, and static recrystallization occurs more fully, so that the main microstructure characteristics of the Ti2AlNb alloy workpiece are all fine equiaxed crystals, the grain size is greatly reduced and the number of grains is increased, so that the mechanical properties of the obtained Ti2AlNb alloy workpiece reach a yield strength of 935.3~1041.2MPa, a tensile strength of 1050.1~1169.3MPa, and an elongation of 20.8~25.7%.

[0104] Example 4

[0105] S1. The Ti-6Al-4V rolled substrate was polished with SiC abrasive and cleaned with acetone. At the same time, the spherical rotating electrode powder was dried in a vacuum environment at 120°C for 2 hours.

[0106] S2. The cleaned Ti-6Al-4V rolled substrate is mounted in the box assembly 1, and the oxygen content of the box assembly 1 is reduced to below 50 ppm by using an argon flow at a flow rate of 10 L / min.

[0107] S3. Using a laser deposition assembly 2 equipped with a three-way coaxial powder feeding laser head 21, the dried spherical rotating electrode powder is used as a raw material to produce a deposition layer of a certain height on the cleaned Ti-6Al-4V rolled substrate according to a preset trajectory.

[0108] Specifically, the process parameters of the laser deposition assembly 2 are: the power of the laser head 21 is 1800W, the scanning rate of the laser head 21 is 10mm / s, the spot diameter of the laser head 21 is 3mm, the overlap rate of the laser head 21 is 30%, and the powder feeding rate of the laser head 21 is 4g / min.

[0109] S4. After the deposition layer obtained in step S3 is cooled for 30 seconds, a laser deposition assembly 2 equipped with a three-way coaxial powder feeding laser head 21 is used to continue manufacturing a single-layer deposition layer according to a preset trajectory using the dried spherical rotating electrode powder as raw material, and continue to generate a deposition layer with a columnar crystal structure.

[0110] S5. Adjust the laser head 21 in the laser deposition assembly 2 according to the preset laser deposited single layer thickness of 0.5-0.6 mm, and repeat steps S4 and S5 until the Ti2AlNb alloy reaches the specified size, thereby obtaining Example 4.

[0111] Example 5

[0112] S1. The Ti-6Al-4V rolled substrate was polished with SiC abrasive and cleaned with acetone. At the same time, the spherical rotating electrode powder was dried in a vacuum environment at 120°C for 2 hours.

[0113] S2. The cleaned Ti-6Al-4V rolled substrate is mounted in the box assembly 1, and the oxygen content of the box assembly 1 is reduced to below 50 ppm by using an argon flow at a flow rate of 10 L / min.

[0114] S3. Using a laser deposition assembly 2 equipped with a three-way coaxial powder feeding laser head 21, the dried spherical rotating electrode powder is used as a raw material to produce a deposition layer of a certain height on the cleaned Ti-6Al-4V rolled substrate according to a preset trajectory.

[0115] Specifically, the process parameters of the laser deposition assembly 2 are: the power of the laser head 21 is 1800W, the scanning rate of the laser head 21 is 5mm / s, the spot diameter of the laser head 21 is 3mm, the overlap rate of the laser head 21 is 30%, and the powder feeding rate of the laser head 21 is 4g / min.

[0116] S4. After the deposition layer obtained in step S3 is cooled for 30 seconds, a laser deposition assembly 2 equipped with a three-way coaxial powder feeding laser head 21 is used to continue manufacturing a single-layer deposition layer according to a preset trajectory using the dried spherical rotating electrode powder as raw material, and continue to generate a deposition layer with a columnar crystal structure.

[0117] S6. Adjust the laser head 21 in the laser deposition assembly 2 according to the preset laser deposited single layer thickness of 0.5-0.6 mm, and repeat steps S4 and S5 until the Ti2AlNb alloy reaches the specified size, thereby obtaining Example 5.

[0118] The workpieces prepared in Examples 1-5 were cut into longitudinal sections perpendicular to the horizontal plane using a wire cutting machine and subjected to metallographic observation and analysis under a high-power microscope. The test results for each group of samples are shown in Table 1.

[0119] Table 1

[0120] ;

[0121] By comparing Example 1 with Example 4, and Example 1 with Example 2, it can be seen that the linear rolling exerts deformation distortion energy on the columnar crystals in the workpiece, so that the secondary laser deposition can induce the recrystallization reaction to generate equiaxed crystals. At the same time, when the reduction amount increases, the deformation distortion energy provided by the linear rolling will also increase accordingly, thereby strengthening the recrystallization reaction and obtaining an equiaxed Ti2AlNb alloy with finer grains.

[0122] By comparing Example 1 with Example 3, and Example 4 with Example 5, it can be seen that when the scanning rate slows down, the thermal effect of laser deposition on the workpiece structure will increase, the recrystallized equiaxed crystals will be larger, and the laser-deposited columnar crystals will also be larger, resulting in a Ti2AlNb alloy with coarser grains.

[0123] Based on the above, a primary laser deposition process uses gradient cooling to generate columnar crystals. Wire rolling then deforms the workpiece to create broken columnar crystals. A secondary laser deposition process, involving high-energy thermal cycling, induces static recrystallization, resulting in equiaxed crystals. The combined effects of wire rolling and laser deposition lead to static recrystallization, a key factor in grain refinement.

[0124] The above embodiments are merely descriptions of preferred implementations of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the scope of protection determined by the claims of the present invention.

Claims

1. A laser deposition and linear rolling method for manufacturing Ti2AlNb alloy, characterized in that: The following steps are involved: S1. The Ti-6Al-4V rolled substrate was polished with SiC abrasive and cleaned with acetone. Meanwhile, the spherical rotating electrode powder was dried in a vacuum environment at 120°C for 2 hours. S2. The cleaned Ti-6Al-4V rolled substrate is mounted in a box assembly, and an argon gas flow is used to reduce the oxygen content of the box assembly to below 50 ppm, thereby preventing the formation of a loose oxide film; S3, using a laser deposition assembly equipped with a three-way coaxial powder feeding laser head, using dried spherical rotating electrode powder as raw material, to produce a deposition layer with a columnar crystal structure of a certain height on a cleaned Ti-6Al-4V rolled substrate according to a preset trajectory; S4. After the deposited layer obtained in step S3 is cooled for a period of time, the deposited layer is linearly rolled using a press assembly equipped with a detachable pressing head. The linear rolling provides deformation and distortion energy, thereby obtaining a deposited layer having a deformed columnar crystal structure. S41, moving the detachable pressing head to above the starting point of the deposition layer obtained in step S3, continuously lowering the detachable pressing head, and reading the value of the extrusion force between the detachable pressing head and the deposition layer through the pressure sensor; S42. When the extrusion force obtained in step S41 exceeds the elastic limit of the material, a low extrusion feed rate V is used to apply plastic deformation to the deposited layer. After the plastic deformation reaches a preset reduction amount, the indenter moves according to a set motion trajectory, and the spherical roller at the tip of the indenter rolls as the indenter moves. After the linear rolling is completed, a deposited layer with a deformed columnar crystal structure is obtained. The expression of the extrusion force is: F=σ e × s Among them, σ e is the elastic limit of the material, s is the area of the detachable indenter; S5. On the deposited layer having the deformed columnar crystal structure obtained in step S4, a laser deposition assembly equipped with a laser head having three coaxial powder feeders is used to continue to produce a single deposited layer along a preset trajectory using the dried spherical rotating electrode powder as a raw material, thereby obtaining a deposited layer having an equiaxed crystal structure. S6. Adjust the laser head in the laser deposition assembly according to the preset single-layer thickness of laser deposition-line rolling, and repeat steps S4 and S5 until the Ti2AlNb alloy reaches a specified size.

2. The laser deposition and linear rolling method for manufacturing Ti2AlNb alloy according to claim 1, characterized in that: In step S1 , the particle size of the spherical rotating electrode powder is 40-130 μm, and the composition of the spherical rotating electrode powder is Ti-22Al-25Nb.

3. The laser deposition and linear rolling method for manufacturing Ti2AlNb alloy according to claim 1, characterized in that: In step S2, the process parameters of the laser deposition assembly are: the power of the laser head is 1400~1800W, the scanning rate of the laser head is 6~10mm / s, the spot diameter of the laser head is 3mm, the overlap rate of the laser head is 30%, and the powder feeding rate of the laser head is 4g / min.

4. The laser deposition and linear rolling method for manufacturing Ti2AlNb alloy according to claim 1, characterized in that: In step S4, the cooling time of the deposited layer is 30 to 60 seconds.

5. The laser deposition and linear rolling method for manufacturing Ti2AlNb alloy according to claim 1 or 4, characterized in that: In step S4, the process parameters of the press assembly are: the press head width of the press is 3~3.5mm, the pressing amount of the press is 0.15~0.35mm, the rolling rate of the press is 0.2mm / s, and the overlap rate of the press is 30%.

6. The laser deposition and linear rolling method for manufacturing Ti2AlNb alloy according to claim 1, characterized in that: In step S6, the thickness of a single layer of the laser deposition-line rolling is 0.5-0.6 mm.

7. An integrated device for laser deposition and linear rolling manufacturing of Ti2AlNb alloy according to any one of claims 1 to 6, characterized in that: It includes a laser deposition assembly, a laser rangefinder assembly, a press assembly and a workbench assembly, wherein the laser deposition assembly, the laser rangefinder assembly, the press assembly and the workbench assembly are respectively located inside a box assembly; The laser deposition assembly includes a laser head, a laser head displacement slider, and a laser head base. The first end of the laser head base is connected to the first mounting end of the bottom of the housing. The second end of the laser head base is connected to the first end of the laser head displacement slider via a lead screw guide assembly. The second end of the laser head displacement slider is provided with a laser head. The laser rangefinder assembly includes a laser rangefinder, a laser rangefinder displacement slider, and a laser rangefinder base. The first end of the laser rangefinder base is connected to the second mounting end of the bottom of the housing. The second end of the laser rangefinder base is connected to the first end of the laser rangefinder displacement slider via a lead screw guide assembly. The second end of the laser rangefinder displacement slider is provided with a laser rangefinder. The press assembly includes a detachable press head, a press displacement slider, and a press base, wherein a first end of the press base is connected to a third mounting end of the bottom of the housing, a second end of the press base is connected to the first end of the press displacement slider via a lead screw guide assembly, and a detachable press head is provided at the second end of the press displacement slider; The workbench assembly includes a workbench, an X-axis displacement guide seat, a Y-axis displacement slider, a Y-axis displacement guide seat and an X-axis displacement slider. The first end of the Y-axis displacement guide seat is connected to the fourth mounting end of the bottom of the shell, the second end of the Y-axis displacement guide seat is connected to the first end of the Y-axis displacement slider through a screw guide assembly, the second end of the Y-axis displacement slider is connected to the first end of the X-axis displacement guide seat, the second end of the X-axis displacement guide seat is connected to the first end of the X-axis displacement slider through a screw guide assembly, the second end of the X-axis displacement slider is connected to the workbench, the workbench is provided with a threaded hole for fixing the workpiece to be processed, and the third end of the X-axis displacement guide seat is provided with a protective cover.

8. The integrated device for laser deposition and linear rolling manufacturing of Ti2AlNb alloy according to claim 7, characterized in that: It also includes a box body assembly, which includes an outer shell, an upper cover, a fixed cover, a box door and an observation window. The upper end of the outer shell is connected to the first end of the upper cover, the second end of the upper cover is connected to the first end of the fixed cover through a fixed cover sealing gasket, the second end of the fixed cover is provided with a gas-liquid quick connector, the front end of the outer shell is respectively connected to the left box door and the right box door through positioning pins, the mounting ends of the left box door and the right box door are respectively provided with box door sealing gaskets, the left end and the right end of the outer shell are respectively symmetrically provided with a left observation window and a right observation window, the mounting ends of the left observation window and the right observation window are respectively provided with observation window sealing gaskets, the first side end and the second side end of the outer shell are respectively provided with a pressure relief valve and an inert gas inlet.

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