Method suitable for preparing high-strength titanium alloy with both strength and plasticity through additive manufacturing process

Abstract

The invention discloses a method suitable for preparing a high-strength titanium alloy with both strength and plasticity by an additive manufacturing process, which comprises the following steps of: 1, carrying out vacuum consumable electrode arc melting on raw materials twice to obtain a secondary cast ingot; secondly, the secondary cast ingot is machined into a round rod, plasma rotating electrode atomization powder manufacturing is conducted on the round rod, and titanium alloy powder is obtained; thirdly, the titanium alloy powder is subjected to electron beam additive manufacturing, and a titanium alloy sample is obtained; and fourthly, the titanium alloy sample is subjected to heat treatment, and the high-strength titanium alloy with both strength and plasticity is obtained. According to the method, the quality of powder is greatly guaranteed through front vacuum consumable electrode electric arc melting and plasma rotating electrode atomization powder preparation, then the titanium alloy sample is obtained through electron beam additive manufacturing, the structure of the titanium alloy sample is regulated and controlled through heat treatment, and the high-strength titanium alloy with the uniform structure and high plasticity is obtained; according to the prepared high-strength titanium alloy with both the strength and the plasticity, the tensile strength is larger than 1300MPa, and meanwhile, the elongation percentage of 5% or above is kept.

Description

Technical Field

[0001] The present invention belongs to the technical field of additive manufacturing of high-strength titanium alloys, and specifically relates to a method for preparing a high-strength titanium alloy having both strength and plasticity by an additive manufacturing process. Background Art

[0002] High-strength titanium alloys are widely used in aerospace and other fields due to their low density, high strength and corrosion resistance. In recent years, the use of additive manufacturing to prepare complex titanium alloy parts has gradually become one of the preferred processes for lightweight aerospace equipment. However, since high-strength titanium alloys contain a large amount of β-stabilizing elements, a large amount of fine needle-like α phases precipitate in the matrix after such alloys are prepared by additive manufacturing, making the elongation of the relevant alloys significantly lower than the forged level.

[0003] In the existing technology, the alloy structure is regulated by additive manufacturing process, and the tensile strength of the obtained high-strength titanium alloy is about 1200-1300MPa, and the elongation is less than 5%, showing the characteristics of high strength and low plasticity. Therefore, in the face of the design and application needs of titanium alloys, it is urgent to develop a high-strength titanium alloy preparation method that takes into account the strength and plasticity of the alloy. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method for preparing a high-strength titanium alloy with both strength and plasticity by additive manufacturing process in view of the shortcomings of the above-mentioned prior art. The method greatly ensures the quality of the powder by pre-vacuum consumable electrode arc melting and plasma rotating electrode atomization powder making, and then uses electron beam additive manufacturing and heat treatment to control the organization of the titanium alloy sample to obtain a high-strength titanium alloy with uniform organization and both strength and plasticity. The prepared high-strength titanium alloy with both strength and plasticity has a tensile strength greater than 1300MPa while maintaining an elongation of more than 5%.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a method for preparing a high-strength titanium alloy with both strength and plasticity by an additive manufacturing process, characterized in that the method comprises the following steps:

[0006] Step 1, subjecting the titanium alloy raw material to vacuum consumable electrode arc primary melting to obtain a primary ingot, and then welding two or three primary ingots and subjecting them to vacuum consumable electrode arc secondary melting to obtain a secondary ingot; the titanium alloy raw material is formulated according to the composition of Ti-5Al-4Cr-4Mo-4V-3Zr;

[0007] Step 2: Processing the secondary ingot obtained in step 1 into a round rod, and then subjecting the round rod to plasma rotating electrode atomization powder making to obtain titanium alloy powder;

[0008] Step 3: Electron beam additive manufacturing is performed on the titanium alloy powder obtained in step 2 to obtain a titanium alloy sample;

[0009] Step 4: heat-treating the titanium alloy sample obtained in step 3 to obtain a high-strength titanium alloy with both strength and plasticity.

[0010] The present invention firstly presses titanium alloy raw materials to obtain a primary consumable electrode, then performs vacuum consumable electrode arc primary melting to obtain a primary ingot, and then welds 2 to 3 primary ingots to obtain a secondary consumable electrode, and performs vacuum consumable electrode arc secondary melting to obtain a secondary ingot, wherein the primary consumable electrode and the secondary consumable electrode are respectively used as cathodes, and a copper crucible is used as an anode. In a vacuum or inert atmosphere, the primary consumable electrode or the secondary consumable electrode is rapidly melted under arc high temperature heating to form a molten pool and stirred, some volatile impurities are diffused to the surface of the molten pool and removed, and the chemical composition of the alloy is fully uniformed after stirring; the present invention processes the secondary ingot into a round rod, and threads are turned at one end to connect with the electrode mandrel of a plasma rotating electrode atomization device, and the round rod is fixed on the rotating electrode device to perform plasma rotating electrode atomization powder making.

[0011] The present invention manufactures titanium alloy powder specially used for additive manufacturing through pre-vacuum consumable electrode arc melting and plasma rotating electrode atomization powder making, which greatly guarantees the quality of the powder, and then uses electron beam additive manufacturing to obtain titanium alloy samples, and then uses heat treatment to regulate the structure of the titanium alloy samples to obtain a high-strength titanium alloy with uniform structure and both strength and plasticity.

[0012] The above-mentioned method for preparing a high-strength titanium alloy with both strength and plasticity by additive manufacturing process is characterized in that the mass of the primary ingot in step 1 is 10kg to 25kg, and the shape is a cylinder with a diameter of 90mm to 120mm and a height of 320mm to 500mm, and the mass of the secondary ingot is 20kg to 50kg, and the shape is a cylinder with a diameter of 120mm to 160mm and a height of 320mm to 500mm. The present invention controls the parameters of vacuum consumable electrode arc melting, so that the prepared secondary ingot is directly used for plasma rotating electrode atomization powder making after simple processing, which effectively improves material utilization and processing efficiency.

[0013] The above-mentioned method for preparing high-strength titanium alloy with both strength and plasticity by additive manufacturing process is characterized in that the processing in step 2 is to process the secondary ingot into a round rod with metallic luster by hot processing or machining, and the diameter of the round rod is 30mm to 75mm. The present invention controls the processing parameters to make the round rod suitable for most plasma rotating electrode atomization equipment.

[0014] The above-mentioned method for preparing a high-strength titanium alloy with both strength and plasticity by an additive manufacturing process is characterized in that, in the plasma rotating electrode atomization powder making process described in step 2, a plasma arc is used to heat and melt the end face of the round rod, and a powder throwing process is performed, wherein the rotation speed of the electrode is 20000r / min~32000r / min, the current is 1100A~1500A, and the voltage is 50V~60V, and then the titanium alloy powder with a particle size of 20μm~150μm is collected through a powder sieve. The present invention controls the parameters of the plasma rotating electrode atomization powder making so that the powder collection rate of the titanium alloy powder with a particle size of 20μm~150μm is greater than 90%, and at the same time, the quality of the titanium alloy powder is also guaranteed, so that the titanium alloy powder is subjected to subsequent treatment to obtain a high-strength titanium alloy with both strength and plasticity.

[0015] The above-mentioned method for preparing a high-strength titanium alloy with both strength and plasticity by additive manufacturing process is characterized in that the parameters of the electron beam additive manufacturing in step 3 are: preheating temperature of 700°C to 760°C, scanning current of 10mA to 17mA, and scanning speed of 3m / s to 6m / s. The present invention effectively takes into account the additive manufacturing accuracy, molding quality and molding efficiency of the titanium alloy by controlling the parameters of the electron beam additive manufacturing, thereby ensuring the performance of the high-strength titanium alloy with both strength and plasticity prepared subsequently.

[0016] The above-mentioned method for preparing a high-strength titanium alloy with both strength and plasticity by additive manufacturing process is characterized in that the heat treatment process described in step four is: the muffle furnace is heated to 850℃~880℃, and then the titanium alloy sample is placed in the muffle furnace, kept warm for 1h~2h, and then cooled to 700℃~750℃ with the furnace at a cooling rate of 0.1℃ / min~0.5℃ / min, and then the titanium alloy sample is taken out and air-cooled to room temperature, and then the muffle furnace is heated to 500℃~580℃, and then the titanium alloy sample air-cooled to room temperature is placed in the muffle furnace, kept warm for 2h~6h, and finally air-cooled. The present invention first heats the muffle furnace to 850°C-880°C, i.e., 30°C-50°C above the phase transformation point, places the titanium alloy sample in the muffle furnace, and keeps it warm for 1h-2h, so that the fine needle-shaped α phase generated in the additive manufacturing process in the titanium alloy sample is dissolved back during the heat treatment and heat preservation process, and then cools the furnace to 700°C-750°C at a cooling rate of 0.1°C / min-0.5°C / min, and then air-cools to room temperature, so that the α phase is discontinuously precipitated and grown on and in the β grain boundary, effectively ensuring the plastic strength of the titanium alloy, and then heats the muffle furnace again to 500°C-580°C, and places the titanium alloy sample air-cooled to room temperature in the muffle furnace, keeps it warm for 2h-6h, and finally air-cools, so that a large amount of basket structure is precipitated in the titanium alloy sample, so that the strength of the titanium alloy is significantly improved under the premise of ensuring that the plasticity is not lower than the engineering use requirement, i.e., the elongation is not lower than 5%.

[0017] The above-mentioned method for preparing a high-strength titanium alloy with both strength and plasticity by additive manufacturing process is characterized in that the high-strength titanium alloy with both strength and plasticity described in step 4 has a tensile strength greater than 1300 MPa while maintaining an elongation of more than 5%.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] 1. The present invention manufactures titanium alloy powder specially used for additive manufacturing by pre-vacuum consumable electrode arc melting and plasma rotating electrode atomization powder making, which greatly guarantees the quality of the powder, and then uses electron beam additive manufacturing to obtain a titanium alloy sample, and then uses heat treatment to regulate the structure of the titanium alloy sample to obtain a high-strength titanium alloy with uniform structure and both strength and plasticity. The prepared high-strength titanium alloy with both strength and plasticity has a tensile strength greater than 1300MPa and an elongation of more than 5%.

[0020] 2. The present invention removes volatile impurities by performing two vacuum consumable electrode arc melting processes to make the chemical composition of the titanium alloy sufficiently uniform. By controlling the parameters of the vacuum consumable electrode arc melting process, the prepared secondary ingot can be directly used for plasma rotating electrode atomization powder making after simple processing, thereby effectively improving material utilization and processing efficiency.

[0021] 3. The present invention controls the parameters of plasma rotating electrode atomization powder making so that the powder collection rate of titanium alloy powder with a particle size of 20μm to 150μm is greater than 90%, while also ensuring the quality of the titanium alloy powder, so that the titanium alloy powder can be obtained through subsequent processing to obtain a high-strength titanium alloy with both strength and plasticity.

[0022] 4. The present invention uses a multi-stage temperature rise and fall heat treatment to cause the fine needle-shaped α phase generated in the additive manufacturing process in the titanium alloy sample to dissolve back during the heat treatment and heat preservation process, so that the α phase discontinuously precipitates and grows on and in the β grain boundaries, effectively ensuring the plastic strength of the titanium alloy, and precipitating a large amount of basketweave structure in the titanium alloy sample, so that the strength of the titanium alloy is significantly improved while ensuring that the plasticity is not lower than the engineering use requirement, that is, the elongation is not lower than 5%.

[0023] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a low-magnification microstructure diagram of a high-strength titanium alloy part having both strength and plasticity prepared in Example 1 of the present invention.

[0025] Figure 2 This is a high-magnification microstructure diagram of a high-strength titanium alloy part having both strength and plasticity prepared in Example 1 of the present invention.

[0026] Figure 3This is a low-magnification microstructure image of the titanium alloy part prepared in Comparative Example 1 of the present invention.

[0027] Figure 4 This is a high-magnification microstructure diagram of the titanium alloy part prepared in Comparative Example 1 of the present invention.

[0028] Figure 5 This is a low-magnification microstructure image of the titanium alloy part prepared in Comparative Example 2 of the present invention.

[0029] Figure 6 This is a high-magnification microstructure diagram of the titanium alloy part prepared in Comparative Example 2 of the present invention. DETAILED DESCRIPTION

[0030] Example 1

[0031] This embodiment includes the following steps:

[0032] Step 1, the titanium alloy raw material is prepared according to the grade of Ti-5Al-4Cr-4Mo-4V-3Zr and subjected to vacuum consumable electrode arc primary melting to obtain a primary ingot with a mass of 10 kg, a cylindrical shape of 90 mm in diameter and 320 mm in height, and then two primary ingots are welded and subjected to vacuum consumable electrode arc secondary melting to obtain a secondary ingot with a mass of 20 kg, a cylindrical shape of 120 mm in diameter and 380 mm in height;

[0033] Step 2: The secondary ingot obtained in step 1 is processed into a round rod with a diameter of 30 mm and a metallic luster by hot working or machining, and the surface oxide scale is removed, and then the round rod is subjected to plasma rotating electrode atomization powder making, and the end face of the round rod is heated and melted by plasma arc, and a powder throwing process is performed, wherein the electrode speed is 28000r / min, the current is 1300A, and the voltage is 50V. Finally, a titanium alloy powder with a particle size of 53μm to 150μm is obtained by powder screening;

[0034] Step 3: The titanium alloy powder obtained in step 2 is subjected to electron beam additive manufacturing at a preheating temperature of 740° C., a scanning current of 16 mA, and a scanning speed of 5 m / s to obtain a titanium alloy sample;

[0035] Step 4: Heat the muffle furnace to 850°C, then place the titanium alloy sample obtained in step 3 in the muffle furnace, keep it warm for 1 hour, then cool it to 750°C with the furnace at a cooling rate of 0.5°C / min, then take out the titanium alloy sample and air-cool it to room temperature, then heat the muffle furnace to 540°C, then place the titanium alloy sample that has been air-cooled to room temperature in the muffle furnace, keep it warm for 4 hours, and finally air-cool it to obtain high-strength titanium alloy parts with both strength and plasticity.

[0036] Comparative Example 1

[0037] This comparative example comprises the following steps:

[0038] Step 1, the titanium alloy raw material is prepared according to the grade of Ti-5Al-4Cr-4Mo-4V-3Zr and subjected to vacuum consumable electrode arc primary melting to obtain a primary ingot with a mass of 10 kg, a cylindrical shape of 90 mm in diameter and 320 mm in height, and then two primary ingots are welded and subjected to vacuum consumable electrode arc secondary melting to obtain a secondary ingot with a mass of 20 kg, a cylindrical shape of 120 mm in diameter and 380 mm in height;

[0039] Step 2: The secondary ingot obtained in step 1 is processed into a round rod with a diameter of 30 mm and a metallic luster by hot working or machining, and the surface oxide scale is removed, and then the round rod is subjected to plasma rotating electrode atomization powder making, and the end face of the round rod is heated and melted by plasma arc, and a powder throwing process is performed, wherein the electrode speed is 28000r / min, the current is 1300A, and the voltage is 50V. Finally, a titanium alloy powder with a particle size of 53μm to 150μm is obtained by powder screening;

[0040] Step 3: The titanium alloy powder obtained in step 2 is subjected to electron beam additive manufacturing at a preheating temperature of 740° C., a scanning current of 16 mA, and a scanning speed of 5 m / s to obtain a titanium alloy part.

[0041] Comparative Example 2

[0042] Step 1, the titanium alloy raw material is prepared according to the grade of Ti-5Al-4Cr-4Mo-4V-3Zr and subjected to vacuum consumable electrode arc primary melting to obtain a primary ingot with a mass of 10 kg, a cylindrical shape of 90 mm in diameter and 320 mm in height, and then two primary ingots are welded and subjected to vacuum consumable electrode arc secondary melting to obtain a secondary ingot with a mass of 20 kg, a cylindrical shape of 120 mm in diameter and 380 mm in height;

[0043] Step 2: The secondary ingot obtained in step 1 is processed into a round rod with a diameter of 30 mm and a metallic luster by hot working or machining, and the surface oxide scale is removed, and then the round rod is subjected to plasma rotating electrode atomization powder making, and the end face of the round rod is heated and melted by plasma arc, and a powder throwing process is performed, wherein the electrode speed is 28000r / min, the current is 1300A, and the voltage is 50V. Finally, a titanium alloy powder with a particle size of 53μm to 150μm is obtained by powder screening;

[0044] Step 3: The titanium alloy powder obtained in step 2 is subjected to electron beam additive manufacturing at a preheating temperature of 740° C., a scanning current of 16 mA, and a scanning speed of 5 m / s to obtain a titanium alloy sample;

[0045] Step 4: Heat the muffle furnace to 760°C, then place the titanium alloy sample obtained in step 3 in the muffle furnace, keep it warm for 1 hour, then take out the titanium alloy sample and air-cool it to room temperature, then heat the muffle furnace to 540°C, then place the titanium alloy sample air-cooled to room temperature in the muffle furnace, keep it warm for 4 hours, and finally air-cool it to obtain titanium alloy parts.

[0046] The mechanical properties of the high-strength titanium alloy parts with both strength and plasticity prepared in Example 1 and the titanium alloy parts prepared in Comparative Examples 1 and 2 were tested. The results are shown in Table 1.

[0047] Table 1

[0048] tensile strength Elongation Example 1 1349±6MPa 7.3±0.9％ Comparative Example 1 1152±22MPa 13.8±1.3％ Comparative Example 2 1249±3MPa 9.0±1.2％

[0049] Combining the process treatments of Example 1, Comparative Example 1 and Comparative Example 2, relative to Example 1, no heat treatment process is performed in Comparative Example 1, and Comparative Example 2 adopts a different heat treatment system. Therefore, the tensile strength of the final titanium alloy parts of Comparative Example 1 and Comparative Example 2 is lower than the standard of Example 1, and the requirements of both strength and plasticity cannot be achieved.

[0050] Figure 1 This is a low-magnification microstructure diagram of a high-strength titanium alloy part having both strength and plasticity prepared in Example 1 of the present invention. Figure 2 This is a high-magnification microstructure diagram of a high-strength titanium alloy part having both strength and plasticity prepared in Example 1 of the present invention. Figure 3 is a low-magnification microstructure diagram of the titanium alloy part prepared in Comparative Example 1 of the present invention, Figure 4 This is a high-magnification microstructure diagram of the titanium alloy part prepared in Comparative Example 1 of the present invention. Figure 5 is a low-magnification microstructure diagram of the titanium alloy part prepared in Comparative Example 2 of the present invention, Figure 6 This is a high-magnification microstructure diagram of the titanium alloy part prepared in Comparative Example 2 of the present invention. Figure 1 to Figure 6 It can be seen that after the high-strength titanium alloy parts with both strength and plasticity prepared in Example 1 are subjected to specific heat treatment, the alloy presents fine lamellar structure in the grains and relatively coarse structure at the grain boundaries, forming a typical two-level heterogeneous structure, achieving the requirements of both strength and plasticity. Coarse lamellar or needle-like α-phase structure was observed in the titanium alloy parts prepared in Comparative Example 1. This structure indicates that the grains are relatively large, the structure has not been effectively refined, and the sample strength requirements cannot be achieved. The organizational morphology of the titanium alloy parts prepared in Comparative Example 2 is similar to that of Comparative Example 1, but the lamellar structure is finer, resulting in poor plasticity of the alloy, and the requirements of both strength and plasticity cannot be achieved either.

[0051] Example 2

[0052] This embodiment includes the following steps:

[0053] Step 1, the titanium alloy raw material is prepared according to the grade of Ti-5Al-4Cr-4Mo-4V-3Zr and subjected to vacuum consumable electrode arc primary melting to obtain a primary ingot with a mass of 25 kg, a cylindrical shape of 120 mm in diameter and 500 mm in height, and then two primary ingots are welded and subjected to vacuum consumable electrode arc secondary melting to obtain a secondary ingot with a mass of 50 kg, a cylindrical shape of 160 mm in diameter and 500 mm in height;

[0054] Step 2: The secondary ingot obtained in step 1 is processed into a round rod with a diameter of 75 mm and a metallic luster by hot working or machining, and the surface oxide scale is removed, and then the round rod is subjected to plasma rotating electrode atomization powder making, and the end face of the round rod is heated and melted by plasma arc, and a powder throwing process is performed, wherein the electrode speed is 20000r / min, the current is 1500A, and the voltage is 55V. Finally, a titanium alloy powder with a particle size of 20μm to 120μm is obtained by powder screening;

[0055] Step 3: The titanium alloy powder obtained in step 2 is subjected to electron beam additive manufacturing at a preheating temperature of 700° C., a scanning current of 10 mA, and a scanning speed of 3 m / s to obtain a titanium alloy sample;

[0056] Step 4: Heat the muffle furnace to 880°C, then place the titanium alloy sample obtained in step 3 in the muffle furnace, keep it warm for 1.5 hours, then cool it to 730°C with the furnace at a cooling rate of 0.1°C / min, then take out the titanium alloy sample and air-cool it to room temperature, then heat the muffle furnace to 580°C, then place the titanium alloy sample that has been air-cooled to room temperature in the muffle furnace, keep it warm for 2 hours, and finally air-cool it to obtain high-strength titanium alloy parts with both strength and plasticity.

[0057] Example 3

[0058] This embodiment includes the following steps:

[0059] Step 1, the titanium alloy raw material is prepared according to the grade of Ti-5Al-4Cr-4Mo-4V-3Zr and subjected to vacuum consumable electrode arc primary melting to obtain a primary ingot with a mass of 13 kg, a cylindrical shape of 90 mm in diameter and 435 mm in height, and then three primary ingots are welded and subjected to vacuum consumable electrode arc secondary melting to obtain a secondary ingot with a mass of 40 kg, a cylindrical shape of 160 mm in diameter and 420 mm in height;

[0060] Step 2: The secondary ingot obtained in step 1 is processed into a round rod with a diameter of 50 mm and a metallic luster by hot working or machining, and the surface oxide scale is removed, and then the round rod is subjected to plasma rotating electrode atomization powder making, and the end face of the round rod is heated and melted by plasma arc, and a powder throwing process is performed, wherein the electrode speed is 32000r / min, the current is 1100A, and the voltage is 60V. Finally, the powder is sieved to obtain a titanium alloy powder with a particle size of 30μm to 130μm;

[0061] Step 3: The titanium alloy powder obtained in step 2 is subjected to electron beam additive manufacturing at a preheating temperature of 760° C., a scanning current of 17 mA, and a scanning speed of 6 m / s to obtain a titanium alloy sample;

[0062] Step 4: Heat the muffle furnace to 860°C, then place the titanium alloy sample obtained in step 3 in the muffle furnace, keep it warm for 2 hours, then cool it to 700°C with the furnace at a cooling rate of 0.3°C / min, then take out the titanium alloy sample and air-cool it to room temperature, then heat the muffle furnace to 550°C, then place the titanium alloy sample that has been air-cooled to room temperature in the muffle furnace, keep it warm for 6 hours, and finally air-cool it to obtain high-strength titanium alloy parts with both strength and plasticity.

[0063] The above is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent change made to the above embodiment according to the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A method for preparing a high-strength titanium alloy with both strength and plasticity by using an additive manufacturing process, characterized in that: The method comprises the following steps: Step 1, subjecting the titanium alloy raw material to vacuum consumable electrode arc primary melting to obtain a primary ingot, and then welding two or three primary ingots and subjecting them to vacuum consumable electrode arc secondary melting to obtain a secondary ingot; the titanium alloy raw material is formulated according to the composition of Ti-5Al-4Cr-4Mo-4V-3Zr; Step 2: Processing the secondary ingot obtained in step 1 into a round rod, and then subjecting the round rod to plasma rotating electrode atomization powder making to obtain titanium alloy powder; Step 3: Electron beam additive manufacturing is performed on the titanium alloy powder obtained in step 2 to obtain a titanium alloy sample; Step 4: heat-treating the titanium alloy sample obtained in step 3 to obtain a high-strength titanium alloy with both strength and plasticity.

2. A method for preparing a high-strength titanium alloy with both strength and plasticity suitable for additive manufacturing process according to claim 1, characterized in that: The mass of the primary ingot in step 1 is 10kg-25kg, and the shape is a cylinder with a diameter of 90mm-120mm and a height of 320mm-500mm. The mass of the secondary ingot is 20kg-50kg, and the shape is a cylinder with a diameter of 120mm-160mm and a height of 320mm-500mm.

3. The method for preparing a high-strength titanium alloy with both strength and plasticity suitable for additive manufacturing process according to claim 1, characterized in that: The processing in step 2 is to process the secondary ingot into a round rod with metallic luster by thermal processing or mechanical processing, and the diameter of the round rod is 30 mm to 75 mm.

4. The method for preparing a high-strength titanium alloy with both strength and plasticity suitable for additive manufacturing process according to claim 1, characterized in that: In the plasma rotating electrode atomization powder making process described in step 2, a plasma arc is used to heat and melt the end face of the round rod, and a powder throwing process is performed, wherein the electrode rotation speed is 20000r / min~32000r / min, the current is 1100A~1500A, the voltage is 50V~60V, and then the titanium alloy powder with a particle size of 20μm~150μm is collected through a powder sieve.

5. The method for preparing a high-strength titanium alloy with both strength and plasticity suitable for additive manufacturing process according to claim 1, characterized in that: The parameters of the electron beam additive manufacturing in step 3 are: preheating temperature of 700° C. to 760° C., scanning current of 10 mA to 17 mA, and scanning speed of 3 m / s to 6 m / s.

6. The method for preparing a high-strength titanium alloy with both strength and plasticity suitable for additive manufacturing process according to claim 1, characterized in that: The heat treatment process described in step 4 is as follows: the muffle furnace is heated to 850°C to 880°C, and then the titanium alloy sample is placed in the muffle furnace, kept warm for 1h to 2h, and then cooled to 700°C to 750°C with the furnace at a cooling rate of 0.1°C / min to 0.5°C / min, and then the titanium alloy sample is taken out and air-cooled to room temperature, and then the muffle furnace is heated to 500°C to 580°C, and then the titanium alloy sample air-cooled to room temperature is placed in the muffle furnace, kept warm for 2h to 6h, and finally air-cooled.

7. The method for preparing a high-strength titanium alloy with both strength and plasticity suitable for additive manufacturing process according to claim 1, characterized in that: The high-strength titanium alloy with both strength and plasticity described in step 4 has a tensile strength greater than 1300 MPa and an elongation greater than 5%.

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