阅读说明：本技术 一种薄壁管状构件的增材制造方法 (Additive manufacturing method of thin-wall tubular component ) 是由 崔烺 朱继宏 赵健 李韶英 冯胜强 刘光 陈杰 贾利 王晓霞 张龙 戴宇 于 2021-06-30 设计创作，主要内容包括：本发明公开了一种薄壁管状构件的增材制造方法,包括以下步骤1)对管状钛基体表面进行除油、干燥及喷砂处理；2)在钛基体的外壁制备铝/不锈钢复合涂层,形成钛-铝/不锈钢复合管基体；3)钛-铝/不锈钢复合管基体的外壁上喷涂金属粉末来增材制造目标涂层；4)将步骤3)中的钛-铝/不锈钢-目标涂层复合管浸泡入加热的氢氧化钠水溶液中,电腐蚀后得到目标涂层对应的管状构件；5)将目标涂层对应的管状构件进行热处理；6)对目标涂层对应的管状构件进行机械加工,最终获得所需的薄壁管状构件。可实现管状构件的薄壁化和大型化；工艺简单、粉末利用率高,极大降低了加工工期,能够实现快速制备薄壁管状构件；内部结合良好,强度较高。(The invention discloses a material increase manufacturing method of a thin-wall tubular component, which comprises the following steps of 1) carrying out oil removal, drying and sand blasting treatment on the surface of a tubular titanium substrate; 2) preparing an aluminum/stainless steel composite coating on the outer wall of the titanium substrate to form a titanium-aluminum/stainless steel composite pipe substrate; 3) spraying metal powder on the outer wall of the titanium-aluminum/stainless steel composite pipe matrix to form a target coating by additive manufacturing; 4) soaking the titanium-aluminum/stainless steel-target coating composite tube in the step 3) into a heated sodium hydroxide aqueous solution, and performing electric corrosion to obtain a tubular component corresponding to the target coating; 5) carrying out heat treatment on the tubular component corresponding to the target coating; 6) and machining the tubular component corresponding to the target coating to finally obtain the required thin-wall tubular component. The tubular member can be thinned and enlarged; the process is simple, the powder utilization rate is high, the processing period is greatly reduced, and the thin-wall tubular component can be rapidly prepared; the internal bonding is good, and the strength is high.)

1. A method for additive manufacturing of a thin-walled tubular member, characterized by: comprises the following steps

1) Clamping the tubular titanium substrate on a machine tool, and performing oil removal, drying and sand blasting treatment on the surface of the tubular titanium substrate;

2) preparing an aluminum/stainless steel composite coating on the outer wall of the titanium substrate in the step 1) to form a titanium-aluminum/stainless steel composite tube substrate;

3) uniformly mixing metal powder corresponding to the target coating, and spraying the metal powder on the outer wall of the titanium-aluminum/stainless steel composite pipe matrix obtained in the step 2) by adopting spraying equipment to perform additive manufacturing on the target coating, so as to obtain a titanium-aluminum/stainless steel-target coating composite pipe; the metal powder corresponding to the target coating is tantalum powder or niobium powder or tantalum alloy powder or niobium alloy powder;

4) soaking the titanium-aluminum/stainless steel-target coating composite pipe in the step 3) into a heated sodium hydroxide aqueous solution, forming galvanic corrosion by using non-corrosion-resistant aluminum and corrosion-resistant stainless steel, accelerating the corrosion of the aluminum/stainless steel composite coating at the middle position, and further removing the aluminum/stainless steel composite coating at the middle position, so that the tubular titanium substrate falls off, and a tubular component corresponding to the target coating is obtained;

5) carrying out heat treatment on the tubular component corresponding to the target coating obtained in the step 4);

6) and (3) machining the tubular member subjected to the heat treatment in the step 5) to finally obtain the required thin-wall tubular member.

2. The method of claim 1, wherein: the titanium substrate in the step 1) is a hollow tube, the diameter of the hollow tube is larger than or equal to 3mm, supersonic speed air flame spraying equipment is used as the sand blasting equipment, the air pressure during sand blasting is 60-80 PSI, the propane pressure is 50-70 PSI, the sand blasting distance is 200-300 mm, and the sand blasting speed is 80-200 g/min.

3. The method of claim 1, wherein: and 2) adopting an aluminum/stainless steel composite powder spraying mode when preparing the aluminum/stainless steel composite coating, wherein the stainless steel is Cr25 duplex stainless steel, the mass percentage of the duplex stainless steel in the aluminum/stainless steel composite powder is 5-30%, the granularity of the duplex stainless steel powder is 70-150 mu m, and the thickness of the aluminum/stainless steel composite coating is more than or equal to 0.2 mm.

4. The method of claim 1, wherein: in the step 2), the preparation method of the aluminum/stainless steel composite coating adopts any one of plasma spraying, oxyacetylene spray welding, supersonic flame spraying and cold spraying.

5. The method of claim 1, wherein: the bulk density of the metal powder corresponding to the target coating in the step 3) is 6-14 g/cm³The target coating has a thickness greater than or equal to 0.2 mm.

6. The method of claim 1, wherein: the spraying in the step 3) is protective atmosphere cold spraying, firstly, the spraying chamber is vacuumized to 600-800 Pa, then nitrogen or argon with the purity not lower than 99% is introduced into the spraying chamber to 0.1-0.3 MPa, and the nitrogen or argon is continuously introduced into the spraying chamber in the spraying process to maintain the pressure in the spraying chamber.

7. The method of claim 1, wherein: the spraying setting adopted in the step 3) comprises any one of a protective atmosphere cold spraying system, a non-protective atmosphere cold spraying system, a helium circulating cold spraying system and a laser-assisted cold spraying system.

8. The method of claim 1, wherein: the mass percentage concentration of the sodium hydroxide aqueous solution in the step 4) is 5-60%, the temperature is 40-100 ℃, and the soaking time is 10-100 hours.

9. The method of claim 1, wherein: the temperature of the heat treatment in the step 5) is 1200-1500 ℃, the time of the heat treatment is 0.5-4 h, and the environment of the heat treatment adopts vacuum heat treatment, argon heat treatment or nitrogen heat treatment.

10. The method of claim 1, wherein: the inner diameter of the tubular member finally obtained in the step 6) is greater than or equal to 3mm, and the wall thickness is greater than or equal to 0.1 mm.

Technical Field

The invention relates to the field of additive manufacturing, in particular to an additive manufacturing method of a thin-wall tubular component.

Background

Tantalum, niobium and alloy materials thereof (Ta-2.5W, Ta-10W, Ta-8W-2Hf, Ta-40Nb, Nb-30W-1Zr and the like) have the characteristics of high melting point, excellent corrosion resistance, good thermal shock resistance, high creep strength, small expansion coefficient, high ductility and the like, and are widely applied to the industries such as the electronic industry, the chemical industry, weapons, aerospace, the atomic energy industry, medical treatment and the like, wherein the tantalum consumption in the electronic industry and the chemical industry accounts for more than 60 percent of the total tantalum consumption. Tantalum, niobium and their alloy materials are used in the electronics and chemical industries in large quantities in the form of tubes for electron emitter tubes, high power electron tubes and for the manufacture of reaction vessels and heat exchangers for chemical processes, pipes, condensers, bayonet heaters, spiral coils, U-tubes, thermocouples, etc.

Tubular members of tantalum, niobium and alloys thereof are generally produced by the processes of integral processing of round bars, powder metallurgy, extrusion-deep drawing (seamless tubes) and cold rolling-welding (seamed tubes). For example, the Chinese patent with the patent number ZL201410116026.2 (with the publication number CN103894442B) discloses a preparation method of a tantalum tube, which mainly comprises the steps of linear cutting of a tantalum ingot, preheating, coating of an antioxidant coating, heating, extrusion, vacuum heat treatment, rolling and vacuum heat treatment, and finally obtaining the required tantalum tube; the Chinese invention application with the application number of 201910207064.1 discloses a method for preparing a tantalum tube by powder metallurgy, which comprises the steps of sieving and stirring metallurgical-grade tantalum powder, quantitatively filling the powder into a soft sleeve with a mold core, putting the soft sleeve into an isostatic press for isostatic pressing solidification, and putting a tantalum powder tube blank obtained by removing an outer sleeve of the soft sleeve and the mold core into a vertical sintering furnace for sintering to obtain a powder metallurgy tantalum tube blank; seamless tubes are produced by extrusion, tube reducing or sheet deep drawing; the seamed tube is formed by forming tantalum blocks into sheet strips, then forming the sheet strips into a tube shape, and welding the seam with Gas Tungsten Arc (GTAW).

Although the above methods can produce tubular members of tantalum, niobium and alloys thereof, there are more or less certain problems:

1) the process of integrally processing the round rod into the tubular member is complex, the processing period is long, and the material waste is large in the process of linear cutting and drilling;

2) the powder metallurgy process is limited by the size of a pressed compact or a sheath and the size and the shape of a hot isostatic pressing device, and the size and the shape of a tubular component are greatly limited;

3) the wall thickness of the seamless tube is uniform and difficult to control, and thin-wall tubular members and large-diameter tubular members are difficult to produce;

4) the seamed pipe has high requirements on the size of the strip and the strength of the weld is not high. These problems have greatly limited the popularity and application of tubular members of tantalum, niobium, and alloys thereof.

Disclosure of Invention

The invention aims to solve the technical problem of the prior art and provides a preparation method of a thin-wall tubular member, which has the advantages of simple process, short processing period and material saving, and the obtained tubular member has unlimited size and higher strength and can be used for producing large-diameter thin-wall tubular members.

The technical scheme adopted by the invention for solving the technical problems is as follows: a method for additive manufacturing of a thin-walled tubular member, characterized by: comprises the following steps

1) Clamping the tubular titanium substrate on a machine tool, and performing oil removal, drying and sand blasting treatment on the surface of the tubular titanium substrate;

2) preparing an aluminum/stainless steel composite coating on the outer wall of the titanium substrate in the step 1) to form a titanium-aluminum/stainless steel composite tube substrate;

3) uniformly mixing metal powder corresponding to the target coating, and spraying the metal powder on the outer wall of the titanium-aluminum/stainless steel composite pipe matrix obtained in the step 2) by adopting spraying equipment to perform additive manufacturing on the target coating, so as to obtain a titanium-aluminum/stainless steel-target coating composite pipe; the metal powder corresponding to the target coating is tantalum powder or niobium powder or tantalum alloy powder or niobium alloy powder;

4) soaking the titanium-aluminum/stainless steel-target coating composite pipe in the step 3) into a heated sodium hydroxide aqueous solution, forming galvanic corrosion by using non-corrosion-resistant aluminum and corrosion-resistant stainless steel, accelerating the corrosion of the aluminum/stainless steel composite coating at the middle position, and further removing the aluminum/stainless steel composite coating at the middle position, so that the tubular titanium substrate falls off, and a tubular component corresponding to the target coating is obtained;

5) carrying out heat treatment on the tubular component corresponding to the target coating obtained in the step 4);

6) and (3) machining the tubular component corresponding to the target coating obtained in the step 5) to finally obtain the required thin-wall tubular component.

As an improvement, the titanium substrate in the step 1) adopts a hollow tube, the diameter of the hollow tube is larger than or equal to 3mm, supersonic speed air flame spraying equipment is used as the sand blasting equipment, the air pressure during sand blasting is 60-80 PSI, the propane pressure is 50-70 PSI, the sand blasting distance is 200-300 mm, and the sand blasting speed is 80-200 g/min.

Further, the aluminum/stainless steel composite coating is prepared in the step 2) by adopting an aluminum/stainless steel composite powder spraying mode, wherein the stainless steel is Cr25 duplex stainless steel, the mass percentage of the duplex stainless steel in the aluminum/stainless steel composite powder is 5-30%, the granularity of the duplex stainless steel powder is 70-150 mu m, and the thickness of the aluminum/stainless steel composite coating is more than or equal to 0.2 mm.

Further, in the step 2), the preparation method of the aluminum/stainless steel composite coating adopts any one of plasma spraying, oxyacetylene spray welding, supersonic flame spraying and cold spraying.

Further, the bulk density of the metal powder corresponding to the target coating in the step 3) is 6-14 g/cm³The target coating has a thickness greater than or equal to 0.2 mm.

Further, the spraying in the step 3) is protective atmosphere cold spraying, firstly, the spraying chamber is vacuumized to 600-800 Pa, then nitrogen or argon with the purity not lower than 99% is introduced into the spraying chamber to 0.1-0.3 MPa, and the nitrogen or argon is continuously introduced into the spraying chamber in the spraying process to maintain the pressure in the spraying chamber.

Further, the spraying setting adopted in the step 3) comprises any one of a protective atmosphere cold spraying system, a non-protective atmosphere cold spraying system, a helium circulating cold spraying system and a laser-assisted cold spraying system.

Further, the mass percentage concentration of the sodium hydroxide aqueous solution in the step 4) is 5-60%, the temperature is 40-100 ℃, and the soaking time is 10-100 hours.

Further, the temperature of the heat treatment in the step 5) is 1200-1500 ℃, the time of the heat treatment is 0.5-4 h, and the environment of the heat treatment adopts vacuum heat treatment, argon heat treatment or nitrogen heat treatment.

Further, the tubular member finally obtained in said step 6) has an inner diameter of 3mm or more and a wall thickness of 0.1mm or more.

Compared with the prior art, the invention has the advantages that:

1. the aluminum/stainless steel composite coating positioned in the middle is corroded by the sodium hydroxide aqueous solution, so that the titanium substrate is separated from the target coating, and the target coating corresponds to the final tubular member; because the two materials of the aluminum/stainless steel have different potentials, galvanic corrosion is easy to form, the galvanic corrosion speed is high, the production speed is further improved, the processing period of the tubular component is greatly reduced, and the tubular component can be quickly prepared; in addition, the titanium substrate and the tubular member are basically not reacted with the sodium hydroxide aqueous solution, the thin-wall tubular member and the titanium substrate are not damaged, and the titanium substrate can be recycled; the target coating corresponding to the tubular component is obtained by adopting a metal powder spraying mode, so that the material removed by drilling the round bar in the prior art is not greatly wasted, and the material can be saved;

2. the thickness of the target coating and the area of the target coating are easily controlled through spraying, so that the final tubular member is convenient to thin and large in size, the wall thickness, the inner diameter and the length of the tubular member are not easily limited by processing equipment like the prior art, and the application of the tubular member can be expanded;

3. the spraying is matched with the galvanic corrosion, and the wall thickness of the tubular component is uniform.

4. The tubular member obtained by the method is tightly combined in the interior and high in density, and compared with welding, the tubular member prepared by the method is high in strength, and the defects of air holes, cracks and the like are not easy to occur in the tubular member.

Drawings

FIG. 1(a) is a schematic illustration of a plasma spray process provided by the present invention, and FIG. 1(b) is a schematic illustration of a cold spray additive manufacturing process;

FIG. 2 is a cross-sectional micro-topography of a plasma-sprayed aluminum/stainless steel composite coating of example 3 of the present invention;

FIG. 3 is a cross-sectional micro-topography of a tantalum tube made by cold spray additive manufacturing of example 3.

Detailed Description

The invention is described in further detail below with reference to the accompanying examples.

Example 1:

referring to fig. 1, an additive manufacturing method of a thin-walled tubular member includes the following steps

1) Clamping the tubular titanium substrate on a machine tool, and performing oil removal, drying and sand blasting treatment on the surface of the tubular titanium substrate; the titanium substrate in the step 1) adopts a hollow pipe, the diameter of the hollow pipe is 3mm, supersonic speed air flame spraying (HVAF) equipment is used as sand blasting equipment, the air pressure during sand blasting is 60PSI, the propane pressure is 50PSI, the sand blasting distance is 250mm, and the sand blasting speed is 80 g/min.

2) Preparing an aluminum/stainless steel composite coating on the outer wall of the titanium substrate in the step 1) to form a titanium-aluminum/stainless steel composite pipe substrate; and 2) preparing the aluminum/stainless steel composite coating by adopting an aluminum/stainless steel composite powder spraying mode, wherein the aluminum/Cr 25 stainless steel composite powder is filled into a plasma powder feeding tank, the stainless steel is Cr25 duplex stainless steel, the mass percentage ratio of the duplex stainless steel in the aluminum/stainless steel composite powder is 30%, the granularity of the duplex stainless steel powder is 70-150 mu m, and the thickness of the aluminum/stainless steel composite coating is 1 mm. In the step 2), the preparation method of the aluminum/stainless steel composite coating adopts plasma spraying, and the plasma spraying can be replaced by any one of oxyacetylene spray welding, supersonic flame spraying and cold spraying.

3) Uniformly mixing metal powder corresponding to the target coating, and spraying the metal powder on the outer wall of the titanium-aluminum/stainless steel composite pipe matrix obtained in the step 2) by adopting spraying equipment to perform additive manufacturing on the target coating, so as to obtain a titanium-aluminum/stainless steel-target coating composite pipe;

in step 3), in this example, the metal powder corresponding to the target coating is tantalum powder, and the loose packed density of the metal powder corresponding to the target coating in step 3) is 6g/cm³The thickness of the target coating was 0.2 mm. The spraying in the step 3) is protective atmosphere cold spraying, firstly, the spraying chamber is vacuumized to 800Pa, then nitrogen or argon with the purity not lower than 99 percent is introduced into the spraying chamber to 0.2MPa, and the nitrogen or argon is continuously introduced into the spraying chamber in the spraying process so as to maintain the pressure in the spraying chamber. That is, the spraying setting adopted in step 3) in this embodiment is a protective atmosphere cold spraying system, and in other embodiments, the protective atmosphere cold spraying system may be replaced by any one of a non-protective atmosphere cold spraying system, a helium gas circulating cold spraying system, and a laser-assisted cold spraying system.

4) Soaking the titanium-aluminum/stainless steel-target coating composite pipe in the step 3) into a heated sodium hydroxide aqueous solution, forming galvanic corrosion by using non-corrosion-resistant aluminum and corrosion-resistant stainless steel, accelerating the corrosion of the aluminum/stainless steel composite coating at the middle position, and further removing the aluminum/stainless steel composite coating at the middle position, so that the tubular titanium substrate falls off, and a tubular component corresponding to the target coating is obtained;

in the step 4), the sodium hydroxide aqueous solution has the mass percentage concentration of 5%, the temperature is 40 ℃, the soaking time is 100 hours, the corrosion of the aluminum/stainless steel composite coating is accelerated by utilizing the galvanic corrosion of the aluminum which is not corrosion-resistant and the corrosion-resistant stainless steel, and then the aluminum/stainless steel composite coating is removed.

5) Carrying out heat treatment on the tubular component corresponding to the target coating obtained in the step 4); and 5) performing heat treatment at 1200 ℃ for 0.5h in the heat treatment environment of vacuum heat treatment or argon heat treatment or nitrogen heat treatment, and cooling to room temperature along with a heating furnace after the heat treatment is finished so as to improve the mechanical properties of the tubular member, particularly the tensile strength, the elongation and the conductivity.

6) And (3) performing linear cutting and abrasive flow inner hole polishing on the tubular component subjected to heat treatment in the step 5) to finally obtain the required thin-wall tubular component, namely the tantalum tube. The tubular member finally obtained in step 6) had an inner diameter of 3mm and a wall thickness of 0.1 mm.

In other embodiments, the metal powder corresponding to the target coating may be replaced by niobium powder or tantalum alloy powder or niobium alloy powder, and accordingly, a tubular member of corresponding material may be obtained.

According to the invention, the aluminum/stainless steel coating in the middle is corroded by the sodium hydroxide aqueous solution, so that the titanium substrate is separated from the target coating, and the target coating corresponds to the final tubular member; because the two materials of aluminum and Cr have different electric potentials, galvanic corrosion is easy to form, the galvanic corrosion speed is high, the production speed is further improved, the processing period of the tubular component is greatly reduced, and the tubular component can be quickly prepared; in addition, the titanium substrate and the tubular member are basically not reacted with the sodium hydroxide aqueous solution, so that the tantalum tube and the titanium substrate are not damaged, and the titanium substrate can be recycled; the target coating corresponding to the tubular component is obtained by adopting the metal powder spraying mode, so that the material removed by punching the round bar in the prior art is not wasted greatly, and the material can be saved.

The thickness of the target coating and the area of the target coating are easily controlled through spraying, so that the final tubular member is convenient to thin and large in size, the wall thickness, the inner diameter and the length of the tubular member are not easily limited by processing equipment like the prior art, and the application of the tubular member can be expanded;

the spraying is matched with the galvanic corrosion, and the wall thickness of the tubular component is uniform.

The tubular member is tightly combined inside and high in density, and compared with welding, the tubular member prepared by the method is high in strength and excellent in performance.

Example 2:

an additive manufacturing method of a thin-wall tubular component comprises the following steps

1) Clamping the tubular titanium substrate on a machine tool, and performing oil removal, drying and sand blasting treatment on the surface of the tubular titanium substrate; the titanium substrate in the step 1) adopts a hollow pipe with the diameter of 10mm, supersonic speed air flame spraying (HVAF) equipment is used as sand blasting equipment, the air pressure during sand blasting is 70PSI, the propane pressure is 60PSI, the sand blasting distance is 300mm, and the sand blasting speed is 100 g/min.

2) Preparing an aluminum/stainless steel composite coating on the outer wall of the titanium substrate in the step 1) to form a titanium-aluminum/stainless steel composite pipe substrate; and 2) preparing the aluminum/stainless steel composite coating by adopting an aluminum/stainless steel composite powder spraying mode, wherein the aluminum/Cr 25 stainless steel composite powder is filled into a plasma powder feeding tank, the stainless steel is Cr25 duplex stainless steel, the mass percentage ratio of the duplex stainless steel in the aluminum/stainless steel composite powder is 20%, the granularity of the duplex stainless steel powder is 70-150 mu m, and the thickness of the aluminum/stainless steel composite coating is 0.5 mm. In the step 2), the preparation method of the aluminum/stainless steel composite coating adopts plasma spraying, and can be oxyacetylene spray welding, supersonic flame spraying or cold spraying.

3) Uniformly mixing metal powder corresponding to the target coating, and spraying the metal powder on the outer wall of the titanium-aluminum/stainless steel composite pipe matrix obtained in the step 2) by adopting spraying equipment to perform additive manufacturing on the target coating, so as to obtain a titanium-aluminum/stainless steel-target coating composite pipe;

in the step 3), the metal powder corresponding to the target coating is tantalum powder; mesh in step 3)The apparent density of the metal powder corresponding to the standard coating is 14g/cm³The thickness of the target coating was 0.3 mm. The spraying in the step 3) is protective atmosphere cold spraying, firstly, the spraying chamber is vacuumized to 700Pa, then nitrogen or argon with the purity not lower than 99 percent is introduced into the spraying chamber to 0.3MPa, and the nitrogen or argon is continuously introduced into the spraying chamber in the spraying process to maintain the pressure in the spraying chamber; correspondingly, the spraying setting adopted in the step 3) comprises a protective atmosphere cold spraying system, and can be replaced by any one of a non-protective atmosphere cold spraying system, a helium circulating cold spraying system and a laser-assisted cold spraying system.

4) Soaking the titanium-aluminum/stainless steel-target coating composite pipe in the step 3) into a heated sodium hydroxide aqueous solution, forming galvanic corrosion by using non-corrosion-resistant aluminum and corrosion-resistant stainless steel, accelerating the corrosion of the aluminum/stainless steel composite coating at the middle position, and further removing the aluminum/stainless steel composite coating at the middle position, so that the tubular titanium substrate falls off, and a tubular component corresponding to the target coating is obtained;

in the step 4), the mass percent concentration of the sodium hydroxide aqueous solution is 30%, the temperature is 80 ℃, and the soaking time is 40 h.

5) Carrying out heat treatment on the tubular component corresponding to the target coating obtained in the step 4); the temperature of the heat treatment in the step 5) is 1300 ℃, the time of the heat treatment is 0.5h, the environment of the heat treatment adopts vacuum heat treatment or argon heat treatment or nitrogen heat treatment, and the furnace is cooled to the room temperature after the heat treatment is finished.

6) And (3) carrying out linear cutting and abrasive flow inner hole polishing on the tubular component subjected to heat treatment in the step 5), and finally obtaining the required thin-wall tubular component, namely the tantalum tube. The tubular member finally obtained in step 6) has an inner diameter of 10mm and a wall thickness of more than 0.1 mm.

Example 3:

an additive manufacturing method of a thin-wall tubular component comprises the following steps

1) Clamping a tubular titanium substrate with the diameter of 30mm on a machine tool, and performing oil removal, drying and sand blasting treatment on the surface of the tubular titanium substrate; the titanium substrate in the step 1) adopts a hollow tube, the sand blasting equipment adopts supersonic speed air flame spraying (HVAF) equipment, the air pressure during sand blasting is 80PSI, the propane pressure is 70PSI, the sand blasting distance is 200mm, and the sand blasting speed is 200 g/min.

2) Preparing an aluminum/stainless steel composite coating on the outer wall of the titanium substrate in the step 1) to form a titanium-aluminum/stainless steel composite pipe substrate; and 2) adopting an aluminum/stainless steel composite powder spraying mode when preparing the aluminum/stainless steel composite coating, specifically adopting plasma spraying equipment, putting the aluminum/Cr 25 stainless steel composite powder into a plasma powder feeding tank, wherein the stainless steel is Cr25 duplex stainless steel, the mass percentage ratio of the duplex stainless steel in the aluminum/stainless steel composite powder is 5%, the granularity of the duplex stainless steel powder is 70-150 mu m, and the thickness of the aluminum/stainless steel composite coating is 0.2 mm. In the step 2), the preparation method of the aluminum/stainless steel composite coating can also adopt any one of oxyacetylene spray welding, supersonic flame spraying and cold spraying.

3) Uniformly mixing metal powder corresponding to the target coating, and spraying the metal powder on the outer wall of the titanium-aluminum/stainless steel composite pipe matrix obtained in the step 2) by adopting spraying equipment to perform additive manufacturing on the target coating, so as to obtain a titanium-aluminum/stainless steel-target coating composite pipe;

in the step 3), the metal powder corresponding to the target coating is tantalum powder; the apparent density of the metal powder corresponding to the target coating in the step 3) is 10g/cm³The thickness of the target coating is greater than 0.2 mm. The spraying in the step 3) is protective atmosphere cold spraying, firstly, the spraying chamber is vacuumized to 600Pa, then nitrogen or argon with the purity not lower than 99 percent is introduced into the spraying chamber to 0.1MPa, and the nitrogen or the argon is continuously introduced into the spraying chamber in the spraying process to maintain the pressure in the spraying chamber; correspondingly, the spraying setting adopted in the step 3) comprises a protective atmosphere cold spraying system, and can be replaced by any one of a non-protective atmosphere cold spraying system, a helium circulating cold spraying system and a laser-assisted cold spraying system.

4) Soaking the titanium-aluminum/stainless steel-target coating composite pipe in the step 3) into a heated sodium hydroxide aqueous solution, forming galvanic corrosion by using non-corrosion-resistant aluminum and corrosion-resistant stainless steel, accelerating the corrosion of the aluminum/stainless steel composite coating at the middle position, and further removing the aluminum/stainless steel composite coating at the middle position, so that the tubular titanium substrate falls off, and a tubular component corresponding to the target coating is obtained, wherein the thickness of the tubular component is more than 0.2 mm;

in the step 4), the mass percent concentration of the sodium hydroxide aqueous solution is 60%, the temperature is 100 ℃, and the soaking time is 10 hours.

5) Carrying out heat treatment on the tubular component corresponding to the target coating obtained in the step 4); the temperature of the heat treatment in the step 5) is 1500 ℃, the time of the heat treatment is 2h, the environment of the heat treatment adopts vacuum heat treatment, the furnace is cooled to room temperature after the heat treatment is finished, and the vacuum heat treatment can be replaced by argon heat treatment or nitrogen heat treatment.

6) And (3) carrying out linear cutting and abrasive particle flow inner hole polishing on the tubular component subjected to heat treatment in the step 5), and finally obtaining the required thin-wall tubular component, namely the tantalum tube. The tubular member finally obtained in step 6) had an internal diameter of 30mm and a wall thickness of more than 0.2 mm.

As is clear from fig. 2 and 3, the tantalum tubular member obtained is relatively dense, and the inside of the tubular member is tightly bonded, so that the strength is high.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the technical principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.