A method of manufacturing a titanium alloy barrel brake with a ta-w coating

Abstract

This invention provides a method for fabricating a titanium alloy gun barrel muzzle brake with a Ta-W coating. The method includes the following steps: Step S1: Printing the annular body of the titanium alloy muzzle brake using laser 3D printing technology; Step S2: Turning and cleaning the inner wall of the printed annular body; Step S3: Clamping the pre-treated annular body on a worktable and simultaneously feeding a mixture of Ta and W powders for laser cladding to form a Ta-W coating on the inner wall of the annular body; Step S4: Machining the clad Ta-W coating to obtain the titanium alloy gun barrel muzzle brake with the Ta-W coating. This invention first uses 3D printing to fabricate a high-strength, low-density titanium alloy muzzle brake to reduce its weight. Then, it uses laser cladding to clad the inner wall of the muzzle brake with a Ta-W coating, forming a Ta-W coating that exhibits a high-strength metallurgical bond with the muzzle brake substrate, thereby significantly improving the muzzle brake's resistance to high-temperature airflow erosion and ablation.

Description

Technical Field

[0001] This invention relates to the field of surface technology, and in particular to a method for preparing a titanium alloy gun barrel recoil device with a Ta-W coating. Background Technology

[0002] Muzzle brakes are often installed at the muzzle of various cannon barrels to reduce the recoil of projectiles. However, ordinary gun steel is prone to erosion and burning under high-temperature, high-pressure combustion gases, leading to premature failure of the muzzle brake's inner wall. Furthermore, steel muzzle brakes are heavy, causing significant bending stress on the barrel. Therefore, it is necessary to reduce the weight of the muzzle brake and to coat its inner wall with a protective coating. The traditional method is chrome plating to improve the muzzle brake's resistance to erosion and burning by high-temperature gases. While chrome plating can extend the muzzle brake's lifespan to some extent, it also has limitations. The inherent microcracks in the coating layer are prone to propagation, eventually forming large cracks that penetrate the interface. This leads to brittle gray and white areas in the substrate, ultimately causing the coating to peel off. Therefore, chromium plating offers limited protection for the muzzle brake. Research has found that higher-performance coatings need to meet the following criteria: high melting point, good high-temperature strength, resistance to ablation by reactive propellant gases, thermomechanical properties matching the substrate, good bonding, and sufficient thickness to protect the muzzle brake from thermal stress-induced mechanical strength reduction. Tantalum and tungsten are known for their high melting points and are widely used. The high-temperature mechanical properties of tantalum and its oxides also meet the requirements of muzzle brake operation. Live-fire target tests have shown good ablation resistance. Pure tantalum (Ta... Adding tungsten (W) is expected to further improve the resistance of Ta coatings to high-temperature gas flow ablation and erosion. If the muzzle brake is manufactured as a whole using an alloy of tantalum and tungsten, the cost would be too high, and the high density of the tantalum-tungsten alloy would cause the barrel to be subjected to excessive bending stress due to the heavy weight of the muzzle brake. Therefore, using a thin Ta-W coating to protect the inner wall of a lightweight titanium alloy muzzle brake is a good solution. However, tantalum and tungsten have negative reduction potentials and cannot be obtained directly from aqueous solutions. Although molten salt plating can achieve molten salt plating of tantalum and tungsten, the high temperature of molten salt plating can easily lead to changes in the microstructure and performance of the base parts. Therefore, it is urgent to develop lightweight muzzle brake parts with an anti-ablation coating on the inner wall. Summary of the Invention

[0003] The purpose of this invention is to overcome and supplement the deficiencies in the existing technology and provide a method for preparing a titanium alloy gun muzzle brake with a Ta-W coating. First, a high-strength and low-density titanium alloy muzzle brake is prepared by 3D printing. Then, a Ta-W coating is clad onto the inner wall of the muzzle brake by laser cladding to improve the muzzle brake's resistance to high-temperature airflow erosion and ablation.

[0004] The technical solution adopted in this invention is:

[0005] A method for preparing a titanium alloy gun barrel muzzle device with a Ta-W coating, wherein: the titanium alloy gun barrel muzzle device includes an annular body and a Ta-W coating disposed on the inner wall of the annular body, and the preparation method includes the following steps:

[0006] Step S1. Use laser 3D printing technology to print the ring-shaped body of the titanium alloy shear brake;

[0007] Step S2. The inner wall of the printed annular body is machined and cleaned;

[0008] Step S3: The pre-treated annular body is clamped on the worktable and mixed powder of Ta and W powder is fed simultaneously for multiple laser cladding to form a Ta-W coating on the inner wall of the annular body.

[0009] Step S4. The clad Ta-W coating is machined. The internal hole dimensional accuracy obtained by machining is not less than IT7 and the surface roughness is not higher than Ra6.3, so as to obtain a titanium alloy gun barrel muzzle device with Ta-W coating.

[0010] Preferably, in the method for preparing the titanium alloy gun barrel muzzle device with Ta-W coating, the material used for printing the annular body in step S1 is dual-phase titanium alloy powder. Different 3D printing technologies are selected according to the size of the part. Small-sized muzzle devices use selective laser melting technology (the maximum length, width and height of the small-sized muzzle device is 250mm*250mm*215mm). Large-sized muzzle devices exceeding this size use laser melting deposition technology. The powder particle size used in selective laser melting technology is 15-53μm, and the powder particle size used in laser melting deposition technology is 53-150μm.

[0011] Preferably, in the method for preparing the titanium alloy gun barrel recoil device with Ta-W coating, the turning speed in step S2 is 30-60 m / min, the feed rate during turning is 0.05-0.15 mm / rpm, and the turning depth is 0.5-1.5 mm.

[0012] Preferably, in the method for preparing the titanium alloy gun barrel recoil device with Ta-W coating, the laser power of the laser cladding in step S3 is 0.8-1kW, the beam scanning rate is 100-200mm / min, the spot size is 1.2-1.5mm, the laser cladding process is protected by argon gas with a flow rate of 6-8L / min, and the overlap is 50%.

[0013] Preferably, in the method for preparing the titanium alloy gun barrel recoil device with Ta-W coating, the particle size of the mixed powder of Ta and W powder in step S3 is 15-53 μm, and the mixed powder includes 75-95% tantalum powder and 5-25% tungsten powder by mass percentage.

[0014] Preferably, in the method for preparing the titanium alloy gun barrel recoil device with Ta-W coating, the thickness of the Ta-W coating prepared by laser cladding in step S3 is 0.6 mm, and the overlap rate between each pass is 50%.

[0015] Preferably, in the method for preparing the titanium alloy gun barrel muzzle device with Ta-W coating, the thickness of the Ta-W coating in step S4 is 0.2-0.4 mm.

[0016] Advantages of this invention:

[0017] (1) The method for preparing a titanium alloy gun muzzle brake with Ta-W coating of the present invention firstly uses 3D printing to prepare a high-strength and low-density titanium alloy muzzle brake, and combines external structural design to reduce the weight of the muzzle brake. Then, a Ta-W coating is clad onto the inner wall of the muzzle brake by laser cladding to form a Ta-W coating that has a high-strength metallurgical bond with the muzzle brake substrate, thereby significantly improving the muzzle brake's resistance to high-temperature airflow erosion and ablation. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the titanium alloy gun barrel recoil device with Ta-W coating of the present invention.

[0019] Figure 2 It is the surface morphology of a traditional gun steel sample after ablation.

[0020] Figure 3 This is the surface morphology of the titanium alloy sample with Ta-W coating after ablation in Example 3. Detailed Implementation

[0021] The present invention will be further described below with reference to specific embodiments and accompanying drawings.

[0022] Example 1

[0023] A method for preparing a titanium alloy gun barrel muzzle device with a Ta-W coating, such as Figure 1 The titanium alloy gun barrel recoil control includes an annular body 1 and a Ta-W coating 2 disposed on the inner wall of the annular body 1. The preparation method includes the following steps:

[0024] Step S1. Place Ti6Al4V powder with a particle size distribution of 53-105μm into the powder feeder of the laser cladding equipment, and use powder feeding laser melting deposition technology to 3D print the retractor to form a ring body 1. The laser power is 2kW, the spot diameter is 0.8mm, and the layer thickness is 0.1mm.

[0025] Step S2. The inner wall of the 3D printed ring body 1 is turned at a turning speed of 50 m / min, a feed rate of 0.1 mm / rpm, and a turning depth of 1 mm. Then the turned surface is cleaned to remove oil stains.

[0026] Step S3. A Ta-W coating 2 is deposited on the inner wall of the annular body 1 using an internal hole laser cladding method. The cladding process parameters are as follows: laser power is 1kW, beam scanning rate is 150mm / min, spot size is 1.5mm, the laser cladding process uses a flow rate of 8L / min, argon protection, and an overlap of 50%. The thickness of the Ta-W coating prepared by laser cladding is 0.6mm, and the overlap rate between each pass is 50%. By mass percentage, the mixed powder includes 92% tantalum powder and 8% tungsten powder.

[0027] Step S4. The clad Ta-W coating is machined to obtain a titanium alloy gun barrel muzzle device with a Ta-8W coating thickness of 0.4 mm.

[0028] The titanium alloy gun muzzle brake with Ta-W coating on the inner wall prepared in Example 1 has a mass reduction of 35.2% compared with the muzzle brake made of conventional gun steel, and a mass ablation rate of 3.72 g / s, which is only 10.26% of the ablation rate of conventional gun steel.

[0029] Example 2

[0030] A method for preparing a titanium alloy gun barrel muzzle device with a Ta-W coating, such as Figure 1 The titanium alloy gun recoil control device includes an annular body 1 and a Ta-W coating 2 disposed on the inner wall of the annular body 1, and includes the following steps:

[0031] S1. Select Ti-6Al-2.5Mo-1.5Cr-0.5Fe-0.3Si powder with a particle size distribution of 15-53 micrometers and place it in the powder spreading chamber of a selective sintering laser printing equipment. Use powder spreading selective laser sintering technology to 3D print the shearer to form a ring body 1. The laser power is 800W, the scanning speed is 3200mm / s, the scanning interval is 0.06, and the single powder spreading thickness is 60μm.

[0032] S2. The inner wall of the 3D printed ring body 1 is turned at a turning speed of 50 m / min, a feed rate of 0.1 mm / rpm, and a turning depth of 1 mm. Then the turned surface is cleaned to remove oil stains.

[0033] S3. An inner wall of the shearer was clad with a Ta-W coating 2 using an internal laser cladding method. The cladding process parameters were as follows: laser power of 0.8kW, beam scanning rate of 150mm / min, spot size of 1.2mm, argon gas protection at a flow rate of 6L / min, and overlap of 50%. The thickness of the Ta-W coating prepared by laser cladding was 0.6mm, and the overlap rate between each pass was 50%. The mixed powder contained 90% tantalum powder and 10% tungsten powder by mass percentage.

[0034] Step S4. The clad Ta-W coating is machined to obtain a titanium alloy gun barrel muzzle device with a Ta-W coating thickness of 0.4 mm.

[0035] The titanium alloy gun muzzle brake with Ta-W coating on the inner wall prepared in Example 2 has a mass reduction of 32.3% compared with the muzzle brake made of conventional gun steel, and a mass ablation rate of 3.125 g / s, which is only 8.62% of the ablation rate of conventional gun steel.

[0036] Example 3

[0037] A method for preparing a titanium alloy gun barrel muzzle device with a Ta-W coating, such as Figure 1 The titanium alloy gun recoil control device includes an annular body 1 and a Ta-W coating 2 disposed on the inner wall of the annular body 1, and includes the following steps:

[0038] S1. Select Ti-6Al-2.5Mo-1.5Cr-0.5Fe-0.3Si powder with a particle size distribution of 15-53 micrometers and place it in the powder spreading chamber of a selective sintering laser printing equipment. Use powder spreading selective laser sintering technology to 3D print the shearer to form a ring body 1. The laser power is 800W, the scanning speed is 3200mm / s, the scanning interval is 0.06, and the single powder spreading thickness is 60μm.

[0039] S2. The inner wall of the 3D printed ring body 1 is turned at a turning speed of 50 m / min, a feed rate of 0.1 mm / rpm, and a turning depth of 1 mm. Then the turned surface is cleaned to remove oil stains.

[0040] S3. An inner wall of the accelerator is clad with a Ta-W coating 2 using an internal hole laser cladding method. The cladding process parameters are: laser power of 0.8kW, beam scanning rate of 150mm / min, spot size of 1.2mm, argon gas protection at a flow rate of 6L / min is used during the laser cladding process, and the overlap is 50%. By mass percentage, the mixed powder includes 88% tantalum powder and 12% tungsten powder.

[0041] Step S4. The clad Ta-W coating is machined to obtain a titanium alloy gun barrel muzzle device with a Ta-W coating thickness of 0.4 mm.

[0042] The titanium alloy gun muzzle brake with Ta-W coating on the inner wall prepared in Example 3 has a mass reduction of 31.5% compared with the muzzle brake made of conventional gun steel, and a mass ablation rate of 2.684 g / s, which is only 7.4% of the ablation rate of conventional gun steel.

[0043] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for preparing a titanium alloy gun barrel recoil device with a Ta-W coating, characterized in that: The titanium alloy gun barrel recoil control includes an annular body (1) and a Ta-W coating (2) disposed on the inner wall of the annular body (1). The preparation method includes the following steps: Step S1. Use laser 3D printing technology to print the ring-shaped body of the titanium alloy heel brake (1); Step S2. The inner wall of the printed annular body (1) is machined and cleaned; Step S3: The pre-treated annular body (1) is clamped on the worktable and mixed powder of Ta and W powder is fed simultaneously for multiple laser cladding to form a Ta-W coating (2) on the inner wall of the annular body (1). Step S4. The clad Ta-W coating (2) is machined to obtain a titanium alloy gun barrel muzzle device with Ta-W coating; The mixed powder comprises 75-95% tantalum powder and 5-25% tungsten powder by mass percentage.

2. The method for preparing the titanium alloy gun barrel recoil device with Ta-W coating according to claim 1, characterized in that: In step S1, the material used for printing the ring body (1) is biphase titanium alloy powder. Different 3D printing technologies are selected according to the size of the helical device. For small-sized helical devices, laser selective melting technology is used, and the powder particle size used in laser selective melting technology is 15-53μm. For large-sized helical devices, laser melting deposition technology is used, and the powder particle size used in laser melting deposition technology is 53-150μm.

3. The method for preparing the titanium alloy gun barrel recoil device with Ta-W coating according to claim 1, characterized in that: In step S2, the turning speed is 30-60 m / min, the feed rate is 0.05-0.15 mm / rpm, and the turning depth is 0.5-1.5 mm.

4. The method for preparing the titanium alloy gun barrel recoil device with Ta-W coating according to claim 1, characterized in that: In step S3, the particle size of the mixed Ta and W powder is 15-53 μm.

5. The method for preparing the titanium alloy gun barrel recoil device with Ta-W coating according to claim 1, characterized in that: In step S3, the thickness of the Ta-W coating prepared by laser cladding is 0.6 mm, and the overlap rate between each pass is 50%.

6. The method for preparing the titanium alloy gun barrel recoil device with Ta-W coating according to claim 1, characterized in that: In step S3, the laser power of laser cladding is 0.8-1kW, the beam scanning rate is 100-200mm / min, the spot size is 1.2-1.5mm, and the laser cladding process is protected by argon gas with a flow rate of 6-8L / min, with an overlap rate of 50%.

7. The method for preparing the titanium alloy gun barrel recoil device with Ta-W coating according to claim 1, characterized in that: In step S4, the thickness of the Ta-W coating on the titanium alloy gun barrel muzzle device is 0.2-0.4 mm.

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