Sleeve extrusion preparation method of powder metallurgy titanium alloy

Abstract

The invention provides a sheathing extrusion preparation method of powder metallurgy titanium alloy, and relates to the technical field of powder metallurgy titanium alloy preparation. The preparation method comprises the following steps: filling titanium alloy powder into a titanium sheath which is consistent with raw material components, and improving the filling density and the bonding strength of the powder by adopting a vibration powder filling and heating degassing process; then, through vacuum low-temperature presintering, it is ensured that powder particles are effectively combined, and grain growth is avoided; and finally, the pre-sintered blank is subjected to extrusion forming, the organization structure of the material is greatly improved, the compactness of the material is improved, full compactness is achieved, the fine-grain structure is guaranteed, and the fine-grain, high-strength and high-plasticity titanium alloy target profile is obtained. By means of the method, production of the high-performance titanium alloy profile in the complex shape can be achieved, multiple steps in a traditional technology are reduced, the production efficiency is remarkably improved, the manufacturing cost is reduced, and the method has important significance on application and popularization of the powder metallurgy titanium alloy profile.

Description

Technical Field

[0001] The present invention relates to the technical field of powder metallurgy titanium alloy preparation, and particularly to a method for preparing powder metallurgy titanium alloy by canned extrusion. Background Art

[0002] Titanium alloys have characteristics such as high specific strength, good corrosion resistance, and good biocompatibility, and are particularly suitable for lightweight design. They are widely used in fields such as aerospace, medical implants, and chemical equipment. However, due to the intrinsic properties of titanium alloys, the traditional casting and forging processes for manufacturing titanium alloys are expensive and have low material utilization rates. The powder metallurgy process has significant advantages in manufacturing complex-shaped and high-performance titanium alloy parts, significantly improving material utilization, having uniform microstructure, and being able to flexibly adjust the composition of titanium alloys to meet different application requirements, thus having broad application prospects.

[0003] Currently, powder metallurgy titanium alloy extruded profiles use spherical titanium alloy powder as raw materials and are manufactured by hot isostatic pressing + hot extrusion. During the hot isostatic pressing process, powder sintering densification is achieved through high temperature and high pressure, and then bars or wires are obtained by extrusion. However, the use of hot isostatic pressing billets is not suitable for direct extrusion forming, and additional machining is required to cut off the hot isostatic can to meet the extrusion requirements. Secondly, better requirements are put forward for the airtightness of the can in hot isostatic pressing. If the degassing is incomplete, residual gases may form pores or inclusions under high temperature and high pressure, reducing the strength, toughness, and other properties of the material, and may also cause hot isostatic pressing chamber explosion, affecting the equipment life. In addition, the hot isostatic pressing process is long, and the accumulation of multiple steps results in low production efficiency and high cost, which is not suitable for rapid or large-scale production requirements. There is an urgent need to develop a high-efficiency and low-cost powder metallurgy titanium alloy extruded profile preparation technology.

[0004] Chinese Patent CN114214536A discloses a method and application for preparing β-type titanium alloy by powder can hot extrusion technology. In this method, pre-alloyed powder is loaded into a hot extrusion can, vacuum-sealed and heated, and then hot extrusion is carried out. After removing the can from the hot extruded sample and performing heat treatment, it is quenched to room temperature to obtain β-type titanium alloy. Therefore, the prepared titanium alloy is poor in strength, hardness, and plasticity and needs heat treatment to improve, and the removal of the can also increases the cost.

[0005] Chinese Patent CN111347045A discloses a step-by-step hot isostatic pressing preparation method for a high-performance powder metallurgy titanium alloy. This method first preforms a sleeve filled with titanium alloy powder at 850 - 900 °C under a pressure of >100 MPa, and then forms it at 920 - 970 °C under a pressure of >100 MPa. The steps are complicated, the operation difficulty is high, the yield strength ratio is close to 1, the hardness is low, more heat and mechanical energy are consumed, the cost is high, and the sleeve also needs to be removed. Chinese Patent CN116571748A also uses hot isostatic pressing to prepare titanium alloy. The sleeve material is steel, and the raw material alloy powder needs to be specially prepared. Hot isostatic pressing preparation requires high temperature and high pressure, and finally the sleeve also needs to be removed. The room temperature strength and hardness are relatively low.

[0006] Chinese Patent CN110607464A discloses a hot isostatic pressing process for Ti2AlNb alloy powder. This process first performs low-temperature pressure holding treatment and then performs heating hot isostatic pressing treatment. Obviously, the temperature of the low-temperature pressure holding is not low, which is equivalent to undergoing two hot isostatic pressing treatments. Although the performance is mentioned, the cost consumed is not low, and the improvement in strength and hardness is not significant, and the plasticity and toughness are relatively poor.

[0007] In this context, the present invention proposes a sleeve extrusion preparation method for powder metallurgy titanium alloy, which overcomes the deficiencies of the traditional hot isostatic pressing process. Through sleeve design + low-temperature pre-sintering, the forming and partial sintering of the powder body are realized, and a billet for extrusion can be obtained without the need for high temperature and high pressure of hot isostatic pressing. The process integration and optimization reduce the steps and improve the production efficiency. The sleeve and the powder have the same composition, avoiding material waste and improving the utilization rate. Finally, full densification of the pre-sintered billet is achieved through extrusion, and a fine-grained structure is ensured, providing technical support for the large-scale industrial production of titanium alloy profiles. Summary of the Invention

[0008] The present invention provides a method for preparing a powder metallurgy titanium alloy by sheath extrusion. Using near-spherical titanium alloy powder as raw material, through designing the sheath structure and adopting vacuum degassing treatment, a high-loading powder-containing sheath is obtained, eliminating the forming processes such as powder cold isostatic pressing, pressing, and hot isostatic pressing. Vibration is introduced during the powder filling process of the sheath to improve the tap density of the powder, reduce pores, thereby increasing the powder loading amount, reducing the sintering shrinkage deformation amount of the powder, effectively reducing the gap between the sintered billet and the inner wall of the sheath in the sheath, and avoiding the problems of low strength and low production efficiency caused by too large a gap during the extrusion process. Through vacuum low-temperature pre-sintering, metallurgical bonding between powder particles in the sheath is achieved, which not only ensures the bonding strength between powder particles but also avoids grain growth, can effectively achieve fine grain strengthening, and at the same time avoids the problems of poor bonding strength and low plasticity of powder particles caused by directly extruding the powder-containing sheath. Finally, the pre-sintered material is directly hot-extruded without cooling, eliminating the billet heating process. The pre-sintering process is the heating process of the extrusion billet, greatly reducing the process flow, reducing energy consumption, reducing manufacturing costs, and avoiding the oxidation risk brought by billet extrusion heating; by extruding the pre-sintered billet, the microstructure of the material is greatly improved, the density of the material is increased, full densification is achieved, and a fine grain structure is ensured, obtaining a target profile of a titanium alloy with fine grains, high strength, and high plasticity. This method integrates the processes of powder filling, degassing, sintering, and extrusion, significantly reducing manufacturing costs while improving production efficiency, and is of great significance for the popularization and application of powder metallurgy titanium alloy profiles.

[0009] In order to obtain the above-mentioned method for preparing a powder metallurgy titanium alloy by sheath extrusion, the method for preparing a powder metallurgy titanium alloy by sheath extrusion comprises the following steps:

[0010] S1. Sheath preparation: Select a material with the same composition as the raw material powder of the powder metallurgy titanium alloy as the sheath material. Seal the bottom of the sheath, and provide a feeding port at the top of the sheath. A valve for controlling the feeding of the feeding port is provided on the feeding port.

[0011] S2. Vibration powder filling: Open the valve in S1, pour the raw material powder of the powder metallurgy titanium alloy into the sheath in S1, and apply vibration to the sheath during the powder pouring process to improve the tap density of the powder in the sheath until the vibration ends after the raw material powder fills the sheath, obtaining a powder-containing sheath with high tap density.

[0012] S3. Heating and degassing: Heat and evacuate the powder-containing sheath in S2. Close the valve when the vacuum degree in the sheath drops below 1 Pa to obtain a vacuum powder-containing sheath.

[0013] S4. Sheath sealing: Weld and seal the feeding port of the vacuum powder-containing sheath in S3 to ensure the vacuum seal of the sheath, and then remove the feeding port valve to obtain a powder-containing sheath with a complete seal.

[0014] S5. Low-temperature pre-sintering: Vertically place the powder-containing sheath in S5 into the sintering furnace with the top of the powder-containing sheath facing upward, and then conduct vacuum sintering to obtain a titanium alloy pre-sintered blank with a sheath.

[0015] S6. Extrusion forming: First preheat the extrusion cylinder, then directly take out the titanium alloy pre-sintered blank in S5 from the sintering furnace without cooling, and then put it into the extruder for extrusion to obtain a high-performance titanium alloy profile.

[0016] Optionally, the powder metallurgy titanium alloy raw material powder in S1 is commercially available titanium and titanium alloy powder, with a sphericity ≥ 70%, a powder particle size of 10 - 100 μm, a tapped density of the powder being 58 - 65% of the theoretical density, and an oxygen content ≤ 0.1 wt%.

[0017] Optionally, the sheath in S1 is a cylindrical titanium can with a diameter of 100 - 1000 mm, a sheath wall thickness of 1 - 10 mm, and a height of 50 - 2000 mm. Select a suitable titanium can according to specific process requirements; the diameter of the feed port is 10 - 50 mm, and the feed port protrudes 20 - 100 mm above the top of the sheath.

[0018] Optionally, the vibration frequency in S2 is 10 - 500 Hz. After vibration, the tapped density of the powder in the sheath is 61 - 75% of the theoretical density, which is 5 - 15% higher than that of the powder in S1.

[0019] Optionally, the heating rate of heating in S3 is 1 - 5 °C / min, the temperature is 100 - 400 °C, and the holding time is 30 - 120 min.

[0020] Optionally, the composition of the welding wire used in S4 is the same as that of the powder metallurgy titanium alloy raw material powder in S1.

[0021] Optionally, the temperature of vacuum sintering in S5 is 980 - 1100 °C, the holding time is 2 - 5 h, the vacuum degree is 10 -1 -10 - 3 Pa, and the sintering relative density of the titanium alloy pre-sintered blank with a sheath is 75 - 85%.

[0022] Optionally, the preheating temperature of the extrusion cylinder in S6 is 300 - 500 °C, the holding time is 0.5 - 1.5 h; the pre-sintered blank is directly taken out from the sintering furnace without cooling, the temperature of the blank is 900 - 1080 °C, the extrusion ratio is 10 - 100, and the extrusion speed is 50 - 200 mm / s.

[0023] Optionally, the shapes of high-performance titanium alloy profiles in S6 include rods, squares, tubes and special shapes. The shape, size and specifications of the profiles are determined by the extrusion die, extrusion ratio and weight of the extruded billet; the tensile strength of the titanium alloy profile is 10-30% higher than that of hot isostatic pressing, and 10-20% higher than that of hot extrusion; the elongation of the titanium alloy profile is 5-15% higher than that of hot isostatic pressing, and 5-10 higher than that of hot extrusion; the high cycle fatigue strength of the titanium alloy profile is more than 30% higher than that of hot isostatic pressing, and 10-20% higher than that of hot extrusion.

[0024] Optionally, the sheath extrusion technology described in S1-S6 is not only applicable to titanium and titanium alloys, but also to iron-based alloys, copper alloys, aluminum alloys and high-temperature alloys.

[0025] Compared with the prior art, the above technical solution has at least the following beneficial effects:

[0026] The above scheme, the present invention proposes a sheath extrusion preparation method for powder metallurgy titanium alloy, optimizes and improves the problems existing in the hot isostatic pressing-extrusion molding technology of powder metallurgy titanium alloy, and has a series of significant beneficial effects. Traditional hot isostatic pressing-extrusion molding technology still faces many limitations in actual production. For example, although hot isostatic pressing can improve the density of powder through high temperature and high pressure conditions, its processing process is complicated and there are problems such as low degassing efficiency and the inability of the blank to be directly used for high extrusion ratio molding. These technical bottlenecks not only affect the final performance of the material, but also significantly limit the promotion and application of titanium alloys in high performance and industrial production. The present invention uses powder-containing sheathing low-temperature sintering-direct extrusion molding to eliminate the hot isostatic pressing sheath cutting and high-temperature and high-pressure sintering processes. The vacuum low-temperature pre-sintering combined with direct extrusion molding ensures the bonding strength between powder particles and avoids grain growth. It also proposes to directly extrude the sintered pre-sintered material without cooling, thereby eliminating the extrusion heating process. The pre-sintering process is the extrusion blank heating process, which greatly shortens the process flow and reduces the manufacturing cost, and finally obtains a fine-grained, high-strength, high-plasticity titanium alloy target profile.

[0027] The present invention plays a key role in the strength, stability and reliability of subsequent processing of the material through the sheath protection design. The use of a titanium alloy sheath with the same composition as the powder material eliminates the composition difference between the sheath material and the powder material, avoids performance degradation caused by inconsistent material composition, and especially eliminates harmful phases or weak bonding areas that may be generated at heterogeneous interfaces under high temperature environments. This consistency of composition eliminates the sheath cutting process after pre-sintering, ensuring the consistency of material composition and performance during processing, which is particularly important in high-demand fields such as aerospace. In order to achieve sheath extrusion, a large number of experiments have been conducted to verify the sphericity (≥70%) and tap density ((0.58~0.65)ρ 理Higher requirements are put forward. After powder vibration filling, the tap density of the powder in the envelope is increased by 5 - 15% on the original basis, and these data cannot be obtained through experience. The requirements for high sphericity and tap density are of great significance for controlling powder sintering shrinkage and extrusion defects.

[0028] Titanium alloy powder is extremely easy to oxidize. The finer the powder and the higher the temperature, the easier it is to oxidize, resulting in a high oxygen content in the titanium alloy and causing brittle fracture of the material. The protective design of the envelope significantly reduces the possible risks during the processing, such as oxidation, impurity pollution or internal defects. It isolates the external atmosphere in a high-temperature environment, prevents the intrusion of harmful gases such as oxygen and nitrogen, and provides a uniform stress environment, ensuring the smooth progress of subsequent forming and processing steps. The physical protection of the envelope significantly improves the structural stability of the billet, ensures the processing reliability during extrusion, reduces the rejection rate and quality fluctuations, and effectively improves the geometric accuracy and surface quality of the finished product.

[0029] In the present invention, through vacuum low-temperature pre-sintering, the powder particles form metallurgical bonds through diffusion and grain boundary migration, which not only ensures the bonding strength between the powder particles, but also avoids grain growth during low-temperature sintering, effectively achieving fine grain strengthening. At the same time, it avoids the problems of poor bonding strength and low plasticity of powder particles caused by direct extrusion of the powder-containing envelope. Finally, a fine-grained sintered billet with good bonding strength and a relative density of 75 - 85% is obtained, providing high-quality raw materials for subsequent extrusion forming, making the microstructure of the finished material finer and more uniform, and greatly improving the mechanical properties. Innovatively, it is proposed to directly extrude the sintered billet, eliminating the secondary heating process of the billet, reducing the risks of oxidation and nitridation of the titanium alloy billet at high temperatures, inhibiting grain growth, significantly reducing energy consumption, shortening the manufacturing process, and reducing the manufacturing cost.

[0030] The present invention exhibits multiple advantages during the material preparation process through the vacuum degassing process, which is of great significance for improving the purity of titanium alloys and optimizing the subsequent processing performance. Under the heating condition of 100 - 400 °C, vacuum treatment is carried out. Through sufficient thermal driving action, the adsorbed gases on the powder surface and the residual gases in the internal micro-pores are effectively removed, significantly reducing the gas content in the material. This process combines a low-vacuum environment (below 1 Pa) with heating conditions, enabling gas impurities, including harmful gases such as oxygen, hydrogen, and nitrogen, to quickly escape from the powder. This process not only improves the purity of the powder but also reduces the oxygen content of the material, preventing the formation of oxide inclusions. Vacuum-sealed welding is another highlight of this process. After degassing, the envelope is efficiently sealed and welded, completely isolating the entry of the external atmosphere, ensuring the high purity of the material during subsequent high-temperature processes. It not only improves the vacuum holding capacity but also avoids further reactions of titanium with external impurities such as oxygen and nitrogen, thus ensuring the chemical stability and purity of the material. By combining vacuum degassing and sealed envelope technologies, the oxygen content of the titanium alloy profile is effectively controlled to ≤0.2 wt.%, and the low oxygen content reduces the formation of oxide inclusions, significantly enhancing the toughness and ductility of the material.

[0031] Through the envelope extrusion technology of the present invention, the density of the titanium alloy profile reaches 100%, eliminating the material pores and greatly improving the mechanical strength and fatigue performance of the titanium alloy. The pre-sintered fine-grained blank is densified by extrusion forming, and by controlling the extrusion ratio, the grain size of the titanium alloy is further refined, with the average grain size being less than or equal to 20 μm. The fine grains significantly improve the mechanical properties of the material, including yield strength, tensile strength, and toughness. Grain refinement also enhances the high-temperature performance of the material, enabling it to have excellent creep and fatigue resistance in high-temperature environments. In addition, the uniform grain distribution avoids the generation of local weaknesses, contributing to improving the reliability and service life of the material.

[0032] By integrating vibration powder filling, degassing, sintering, and extrusion forming into an integrated process, the present invention greatly shortens the process flow and significantly reduces the cumbersome steps in the traditional process. For example, by introducing vibration powder filling technology, the tap density is effectively increased during the powder filling process, reducing the voids between the powders and greatly improving the uniformity of the material and the quality of the final product. And the extrusion forming is directly carried out using the high-temperature heat of the pre-sintered blank, eliminating the secondary heating and extrusion process of the traditional sintered blank. This integrated process design not only saves time but also improves the overall production efficiency.

[0033] In summary, compared with the traditional powder metallurgy hot isostatic pressing for preparing titanium alloys that requires removing the cladding, the present invention has successfully overcome the limitations of the traditional hot isostatic pressing + hot extrusion process through the innovative powder metallurgy titanium alloy cladding extrusion technology, providing an efficient and reliable solution for the preparation and processing of titanium alloy materials. With the core of a titanium or titanium alloy cladding design with consistent composition, combined with optimized vacuum degassing, sealed welding, and low-temperature pre-sintering technologies, remarkable results have been achieved in aspects such as material densification, grain refinement, and impurity control. By enhancing the strength and stability of the billet through cladding protection, it effectively prevents cracking and deformation during the processing, isolates the powder contamination problem, and at the same time, vacuum low-temperature sintering enables the powder particles to be metallurgically bonded and has a fine-grained structure, providing a reliable guarantee for the production of high-performance titanium alloy profiles. The density of the extruded titanium alloy profiles is 100%, the grain size is controlled within 20 μm, and the oxygen content is ≤ 0.2 wt.%, showing excellent mechanical properties and chemical stability. In addition, the integrated one-piece forming process simplifies the traditional process, significantly improves the production efficiency and product quality, opens up a new path for the preparation of high-performance titanium alloys in fields such as aerospace and medical devices, and demonstrates broad application prospects and industrial value. Brief Description of the Drawings

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0035] Figure 1 It is a process flow diagram of the specific preparation steps of a method for preparing a powder metallurgy titanium alloy by cladding extrusion of the present invention. Detailed Embodiments

[0036] The following will describe the technical solutions in the present invention in conjunction with the drawings.

[0037] In the embodiments of the present invention, words such as "exemplarily" and "for example" are used to represent examples, illustrations, or explanations. Any embodiment or design solution described as "example" in the present invention should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Exactly speaking, the use of the word "example" aims to present concepts in a specific way. In addition, in the embodiments of the present invention, the meaning expressed by "and / or" can be both, or either one of the two can be selected.

[0038] In the embodiments of the present invention, "image" and "picture" can sometimes be used interchangeably. It should be noted that when the difference is not emphasized, the meanings they express are the same.

[0039] In the embodiments of the present invention, sometimes a subscript such as W1 may be written in a non-subscript form such as W1. When the difference is not emphasized, the meanings they express are the same.

[0040] To make the technical problems, technical solutions, and advantages to be solved by the present invention clearer, the following will be described in detail with reference to the accompanying drawings and specific embodiments.

[0041] A method for preparing a powder metallurgy titanium alloy by sheath extrusion, the method for preparing a powder metallurgy titanium alloy by sheath extrusion combines Figure 1 the following steps:

[0042] S1. Sheath preparation: Select a material with the same composition as the raw material powder of the powder metallurgy titanium alloy as the sheath material, seal the bottom of the sheath, and provide a feed port at the top of the sheath. A valve for controlling the feeding of the feed port is provided on the feed port;

[0043] S2. Vibration powder filling: Open the valve in S1, pour the raw material powder of the powder metallurgy titanium alloy into the sheath in S1, and apply vibration to the sheath during the powder pouring process to improve the tap density of the powder in the sheath. Stop vibrating until the raw material powder fills the sheath, and obtain a high-tap density powder-containing sheath;

[0044] S3. Heating and degassing: Heat and evacuate the powder-containing sheath in S2, close the valve when the vacuum degree in the sheath is reduced to below 1 Pa, and obtain a vacuum powder-containing sheath;

[0045] S4. Sheath sealing: Weld and seal the feed port of the vacuum powder-containing sheath in S3 to ensure the vacuum seal of the sheath, and then remove the feed port valve to obtain a powder-containing sheath with a complete seal;

[0046] S5. Low-temperature pre-sintering: Vertically place the powder-containing sheath in S5 into a sintering furnace, keep the top of the powder-containing sheath facing upward, and then perform vacuum sintering to obtain a titanium alloy pre-sintered blank with a sheath;

[0047] S6. Extrusion forming: First preheat the extrusion cylinder, then directly take out the titanium alloy pre-sintered blank in S5 from the sintering furnace without cooling, and then put it into an extruder for extrusion to obtain a high-performance titanium alloy profile.

[0048] Particularly, the raw material powder of the powder metallurgy titanium alloy in S1 is a commercially available titanium and titanium alloy powder, with a sphericity ≥ 70%, a powder particle size of 10 - 100 μm, a powder tap density of 58 - 65% of the theoretical density, and an oxygen content ≤ 0.1 wt%.

[0049] Specifically, the jacket in S1 is a cylindrical titanium can with a diameter of 100 - 1000 mm, a jacket wall thickness of 1 - 10 mm, and a height of 50 - 2000 mm. A suitable titanium can is selected according to specific process requirements; the diameter of the feed port is 10 - 50 mm, and the feed port protrudes 20 - 100 mm above the top of the jacket.

[0050] Specifically, the vibration frequency in S2 is 10 - 500 Hz. After vibration, the tapped density of the powder in the jacket is 61 - 75% of the theoretical density, which is 5 - 15% higher than that in S1.

[0051] Specifically, the heating rate of heating in S3 is 1 - 5 °C / min, the temperature is 100 - 400 °C, and the holding time is 30 - 120 min.

[0052] Specifically, the composition of the welding wire used in S4 is the same as that of the powder metallurgy titanium alloy raw material powder in S1.

[0053] Specifically, the temperature of vacuum sintering in S5 is 980 - 1100 °C, the holding time is 2 - 5 h, and the vacuum degree is 10 -1 -10 - 3 Pa, and the sintering relative density of the titanium alloy pre-sintered blank with the jacket is 75 - 85%.

[0054] Specifically, the preheating temperature of the extrusion cylinder in S6 is 300 - 500 °C, and the holding time is 0.5 - 1.5 h; the pre-sintered blank is taken out directly from the sintering furnace without cooling, the temperature of the blank is 900 - 1080 °C, the extrusion ratio is 10 - 100, and the extrusion rate is 50 - 200 mm / s.

[0055] Specifically, the shapes of the high-performance titanium alloy profiles in S6 include rod-shaped, square-shaped, tubular, and irregular shapes. The shape, size, and specifications of the profiles are determined according to the extrusion die, extrusion ratio, and weight of the extrusion blank; the tensile strength of the titanium alloy profiles is 10 - 30% higher than that of hot isostatic pressing and 10 - 20% higher than that of hot extrusion; the elongation of the titanium alloy profiles is 5 - 15% higher than that of hot isostatic pressing and 5 - 10% higher than that of hot extrusion; the high-cycle fatigue strength of the titanium alloy profiles is more than 30% higher than that of hot isostatic pressing and 10 - 20% higher than that of hot extrusion.

[0056] Specifically, the jacket extrusion technology described in S1 - S6 is applicable not only to titanium and its alloys, but also to iron-based alloys, copper alloys, aluminum alloys, and superalloys.

[0057] Example 1

[0058] The method for preparing a powder metallurgy titanium alloy by jacket extrusion in this example is as follows:

[0059] S1. Sheath Preparation: Select a material with the same composition as the powder metallurgy titanium alloy raw material powder as the sheath material. The sheath is a cylindrical titanium can with a diameter of 300 mm, a sheath wall thickness of 4 mm, and a height of 700 mm. A valve for controlling the feeding of the feeding port is provided on the feeding port. The diameter of the feeding port is 50 mm, and the feeding port protrudes 30 mm above the top of the sheath. The bottom of the sheath is sealed, and a feeding port is provided at the top of the sheath. Among them, the powder metallurgy titanium alloy raw material powder uses commercially available TC4 titanium alloy powder, with a powder sphericity of 90%, a powder particle size of 30 μm, a tapped density of the powder being 61% of the theoretical density, and an oxygen content of 0.07 wt%.

[0060] S2. Vibratory Powder Filling: Open the valve in S1, pour the powder metallurgy titanium alloy raw material powder into the sheath in S1, and apply vibration to the sheath during the powder pouring process to increase the tapped density of the powder in the sheath. The vibration frequency is 40 Hz. Stop vibrating until the raw material powder fills the sheath. After vibration stops, the tapped density of the powder in the sheath is 65% of the theoretical density, obtaining a high-tapped density powder-containing sheath.

[0061] S3. Heating and Degassing: Heat and evacuate the powder-containing sheath in S2. The heating rate of temperature rise is 1 °C / min, the temperature is 200 °C, and the holding time is 50 min. Close the valve until the vacuum degree in the sheath drops below 1 Pa, obtaining a vacuum powder-containing sheath.

[0062] S4. Sheath Sealing: Weld and seal the feeding port of the vacuum powder-containing sheath in S3. The composition of the welding wire is the same as that of the powder metallurgy titanium alloy raw material powder in S1 to ensure the vacuum seal of the sheath, and then remove the feeding port valve to obtain a powder-containing sheath with a complete seal.

[0063] S5. Low-Temperature Pre-Sintering: Vertically place the powder-containing sheath in S5 into the sintering furnace with the top of the powder-containing sheath facing upward, and then conduct vacuum sintering. The temperature of the vacuum sintering is 1100 °C, the holding time is 2 h, and the vacuum degree is 10 -3 Pa. The sintering density of the titanium alloy pre-sintered blank with the sheath is 80%, obtaining a titanium alloy pre-sintered blank with a sheath.

[0064] S6. Extrusion Forming: First, preheat the extrusion cylinder. The preheating temperature is 450 °C, and the holding time is 1.0 h. Then, directly take out the titanium alloy pre-sintered blank in S5 from the sintering furnace without cooling. The temperature of the blank is 1060 °C, and then put it into the extruder for extrusion. The extrusion ratio is 36, and the extrusion rate is 50 mm / s, obtaining a rod-shaped high-performance titanium alloy profile.

[0065] The hardness of the titanium alloy profile prepared in this example is 35 HRC, the tensile strength is 1150 MPa, the yield strength is 1075 MPa, the elongation is 15.7%, and the elastic modulus is 120 GPa.

[0066] Example 2

[0067] The method for preparing a powder metallurgy titanium alloy by cladding extrusion in this example is as follows:

[0068] S1. Cladding preparation: Select a material with the same composition as the powder metallurgy titanium alloy raw material powder as the cladding material. The cladding is a cylindrical titanium can with a diameter of 500 mm, a cladding wall thickness of 6 mm, and a height of 900 mm. A valve for controlling the feeding of the feeding port is provided on the feeding port. The diameter of the feeding port is 60 mm, and the feeding port protrudes 25 mm above the top of the cladding. The bottom of the cladding is sealed, and a feeding port is provided at the top of the cladding. Among them, the powder metallurgy titanium alloy raw material powder is commercially available TA15 titanium alloy powder, with a powder sphericity of 93%, a powder particle size of 20 μm, a tapped density of the powder being 63% of the theoretical density, and an oxygen content of 0.05 wt%.

[0069] S2. Vibration powder filling: Open the valve in S1, pour the powder metallurgy titanium alloy raw material powder into the cladding in S1, and apply vibration to the cladding during the powder pouring process to increase the tapped density of the powder in the cladding. The vibration frequency is 50 Hz. Stop vibrating until the raw material powder fills the cladding. After vibration stops, the tapped density of the powder in the cladding is 69% of the theoretical density, and a high-tapped density powder-containing cladding is obtained.

[0070] S3. Heating and degassing: Heat and evacuate the powder-containing cladding in S2. The heating rate of temperature rise is 3 °C / min, the temperature is 300 °C, and the holding time is 40 min. Close the valve until the vacuum degree in the cladding drops below 1 Pa, and a vacuum powder-containing cladding is obtained.

[0071] S4. Cladding sealing: Weld and seal the feeding port of the vacuum powder-containing cladding in S3. The composition of the welding wire is the same as that of the powder metallurgy titanium alloy raw material powder in S1 to ensure the vacuum sealing of the cladding. Then remove the feeding port valve to obtain a powder-containing cladding with a complete seal.

[0072] S5. Low-temperature pre-sintering: Vertically place the powder-containing cladding in S5 into a sintering furnace with the top of the powder-containing cladding facing up, and then carry out vacuum sintering. The temperature of the vacuum sintering is 1050 °C, the holding time is 3 h, and the vacuum degree is 10 -3 Pa. The sintering density of the titanium alloy pre-sintered blank with the cladding is 82%, and a titanium alloy pre-sintered blank with the cladding is obtained.

[0073] S6. Extrusion forming: First, preheat the extrusion cylinder. The preheating temperature is 300 °C and the heat preservation time is 1.5 h. Then, directly take out the titanium alloy pre-sintered blank in S5 from the sintering furnace without cooling. The temperature of the blank is 1000 °C, and then put it into the extruder for extrusion. The extrusion ratio is 45 and the extrusion rate is 100 mm / s to obtain a square-shaped high-performance titanium alloy profile.

[0074] The hardness of the titanium alloy profile prepared in this example is 340 HV, the tensile strength is 1064 MPa, the yield strength is 1020 MPa, the elongation is 15.2%, and the elastic modulus is 118 GPa.

[0075] Example 3

[0076] The following is the method for preparing a powder metallurgy titanium alloy by cladding extrusion in this example:

[0077] S1. Cladding preparation: Select a material with the same composition as the powder metallurgy titanium alloy raw material powder as the cladding material. The cladding is a cylindrical titanium can with a diameter of 700 mm, a cladding wall thickness of 8 mm, and a height of 1000 mm. A valve for controlling the feeding of the feeding port is provided on the feeding port. The diameter of the feeding port is 80 mm, and the feeding port protrudes 45 mm above the top of the cladding. The bottom of the cladding is sealed, and a feeding port is provided at the top of the cladding. Among them, the powder metallurgy titanium alloy raw material powder uses commercially available TA1 titanium alloy powder, the powder sphericity is 70%, the powder particle size is 50 μm, the tapped density of the powder is 58% of the theoretical density, and the oxygen content is 0.09 wt%.

[0078] S2. Vibrating powder filling: Open the valve in S1 and pour the powder metallurgy titanium alloy raw material powder into the cladding in S1. During the powder pouring process, vibrate the cladding simultaneously to improve the tapped density of the powder in the cladding. The vibration frequency is 90 Hz. Stop vibrating until the raw material powder fills the cladding. After the vibration stops, the tapped density of the powder in the cladding is 61% of the theoretical density to obtain a high-tapped density powder-containing cladding.

[0079] S3. Heating and degassing: Heat and evacuate the powder-containing cladding in S2. The heating rate of temperature rise is 2 °C / min, the temperature is 400 °C, and the heat preservation time is 30 min. Close the valve until the vacuum degree in the cladding drops below 1 Pa to obtain a vacuum powder-containing cladding.

[0080] S4. Cladding sealing: Weld and seal the feeding port of the vacuum powder-containing cladding in S3. The composition of the welding wire is the same as that of the powder metallurgy titanium alloy raw material powder in S1 to ensure the vacuum seal of the cladding. Then remove the feeding port valve to obtain a powder-containing cladding with a complete seal.

[0081] S5. Low-temperature pre-sintering: Vertically place the powder-containing cladding in S5 into the sintering furnace with the top of the powder-containing cladding facing upward, and then conduct vacuum sintering. The temperature of the vacuum sintering is 1000 °C, the holding time is 4.5 h, and the vacuum degree is 10 -3 Pa. The sintering relative density of the pre-sintered titanium alloy blank with the cladding is 76%, and a pre-sintered titanium alloy blank with the cladding is obtained;

[0082] S6. Extrusion forming: First, preheat the extrusion cylinder. The preheating temperature is 400 °C, and the holding time is 1.0 h. Then, directly take out the pre-sintered titanium alloy blank in S5 from the sintering furnace without cooling. The temperature of the blank is 960 °C, and then put it into the extruder for extrusion. The extrusion ratio is 30, and the extrusion rate is 150 mm / s to obtain a high-performance tubular titanium alloy profile.

[0083] The hardness of the titanium alloy profile prepared in this example is 185 HV, the tensile strength is 672 MPa, the yield strength is 597 MPa, the elongation is 26%, and the elastic modulus is 107 GPa.

[0084] Example 4

[0085] The steps of a method for preparing a powder metallurgy titanium alloy by cladding extrusion in this example are as follows:

[0086] S1. Cladding preparation: Select a material with the same composition as the powder metallurgy titanium alloy raw material powder as the cladding material. The cladding is a cylindrical titanium can with a diameter of 600 mm, a cladding wall thickness of 7 mm, and a height of 800 mm. A valve for controlling the feeding of the feeding port is provided on the feeding port. The diameter of the feeding port is 60 mm, and the feeding port protrudes 30 mm above the top of the cladding. The bottom of the cladding is sealed, and a feeding port is provided at the top of the cladding. Among them, the powder metallurgy titanium alloy raw material powder is commercially available TB15 titanium alloy powder, the powder sphericity is 85%, the powder particle size is 75 μm, the tapped density of the powder is 60% of the theoretical density, and the oxygen content is 0.06 wt%;

[0087] S2. Vibration powder filling: Open the valve in S1, pour the powder metallurgy titanium alloy raw material powder into the cladding in S1, and apply vibration to the cladding during the powder pouring process to increase the tapped density of the powder in the cladding. The vibration frequency is 50 Hz. Stop vibrating until the raw material powder fills the cladding. After vibration stops, the tapped density of the powder in the cladding is 65% of the theoretical density, and a high-tapped powder-containing cladding is obtained;

[0088] S3. Heating and degassing: Heat and evacuate the powder-containing cladding in S2. The heating rate of temperature rise is 4 °C / min, the temperature is 300 °C, and the holding time is 50 min. Close the valve until the vacuum degree in the cladding drops below 1 Pa to obtain a vacuum powder-containing cladding;

[0089] S4. Cladding Sealing: Weld and seal the feed port of the vacuum powder-containing cladding in S3. The composition of the welding wire is the same as that of the powder metallurgy titanium alloy raw material powder in S1 to ensure the vacuum seal of the cladding. Then remove the feed port valve to obtain a powder-containing cladding with a complete seal.

[0090] S5. Low-temperature Presintering: Vertically place the powder-containing cladding in S5 into a sintering furnace with the top of the powder-containing cladding facing upward. Then conduct vacuum sintering at a temperature of 1100 °C, a holding time of 2 h, and a vacuum degree of 10 -3 Pa. The sintering density of the titanium alloy pre-sintered blank with the cladding is 78% to obtain a titanium alloy pre-sintered blank with the cladding.

[0091] S6. Extrusion Forming: First, preheat the extrusion cylinder at a preheating temperature of 400 °C and a holding time of 0.5 h. Then directly take out the titanium alloy pre-sintered blank in S5 from the sintering furnace without cooling. The temperature of the blank is 1050 °C, and then place it in an extruder for extrusion. The extrusion ratio is 36, and the extrusion rate is 100 mm / s to obtain a semi-circular high-performance titanium alloy profile.

[0092] The hardness of the titanium alloy profile prepared in this example is 30 HRC, the tensile strength is 1119 MPa, the yield strength is 1048 MPa, the elongation is 16.5%, and the elastic modulus is 110 GPa.

[0093] In the above solution, the present invention proposes a method for preparing a powder metallurgy titanium alloy by cladding extrusion, which optimizes and improves the problems existing in the powder metallurgy titanium alloy hot isostatic pressing-extrusion forming technology and has a series of remarkable beneficial effects. The traditional hot isostatic pressing-extrusion forming technology still faces many limitations in actual production. For example, although hot isostatic pressing can improve the densification of powders through high-temperature and high-pressure conditions, its processing process is complex and there are problems such as low degassing efficiency and the blank cannot be directly used for high-extrusion ratio forming. These technical bottlenecks not only affect the final properties of the material but also significantly limit the popularization and application of titanium alloys in high-performance and industrial production. The present invention omits the hot isostatic pressing cladding cutting and high-temperature and high-pressure sintering processes through low-temperature sintering-direct extrusion forming of the powder-containing cladding. Through vacuum low-temperature presintering combined with direct extrusion forming, it not only ensures the bonding strength between powder particles but also avoids grain growth. It is proposed to directly extrude the sintered pre-sintered material without cooling, omitting the extrusion heating process. The presintering process is the extrusion blank heating process, greatly reducing the process flow and manufacturing cost, and finally obtaining a fine-grained, high-strength, and high-plasticity titanium alloy target profile.

[0094] The present invention plays a key role in the strength, stability and reliability of subsequent processing of the material through the sheath protection design. The use of a titanium alloy sheath with the same composition as the powder material eliminates the composition difference between the sheath material and the powder material, avoids performance degradation caused by inconsistent material composition, and especially eliminates harmful phases or weak bonding areas that may be generated at heterogeneous interfaces under high temperature environments. This consistency of composition eliminates the sheath cutting process after pre-sintering, ensuring the consistency of material composition and performance during processing, which is particularly important in high-demand fields such as aerospace. In order to achieve sheath extrusion, a large number of experiments have been conducted to verify the sphericity (≥70%) and tap density ((0.58~0.65)ρ 理 ) puts forward higher requirements. After vibration powder filling, the tap density of powder in the bag is increased by 5-15% on the original basis. These data cannot be obtained through experience. High sphericity and tap density requirements are of great significance to control powder sintering shrinkage and extrusion defects.

[0095] Titanium alloy powder is very easy to oxidize. The finer the powder, the higher the temperature, the easier it is to oxidize, resulting in a high oxygen content in the titanium alloy, causing the material to break brittlely. The protective design of the sheath significantly reduces the risks that may occur during processing, such as oxidation, impurity contamination or internal defects. It isolates the external atmosphere in a high temperature environment, prevents the intrusion of harmful gases such as oxygen and nitrogen, and provides a uniform stress environment, ensuring the smooth progress of subsequent forming and processing steps. The physical protection of the sheath significantly improves the structural stability of the billet, ensures the processing reliability during the extrusion process, reduces the scrap rate and quality fluctuations, and effectively improves the geometric accuracy and surface quality of the finished product.

[0096] The present invention uses vacuum low-temperature pre-sintering to form metallurgical bonds between powder particles through diffusion and grain boundary migration, which not only ensures the bonding strength between powder particles, but also avoids grain growth through low-temperature sintering, which can effectively achieve fine grain strengthening, and avoids the problem of poor bonding strength and low plasticity of powder particles caused by direct extrusion of powder-containing sheaths, and finally obtains fine-grained sintered blanks with good bonding strength and a density of 75-85%, providing high-quality raw materials for subsequent extrusion molding, making the microstructure of the finished material more fine and uniform, and greatly improving the mechanical properties. It is innovatively proposed to directly extrude the sintered blank, eliminating the secondary heating process of the blank, reducing the risk of oxidation and nitridation of the titanium alloy blank at high temperature, inhibiting grain growth, and greatly reducing energy consumption, shortening the manufacturing process, and reducing manufacturing costs.

[0097] The present invention exhibits multiple advantages during the material preparation process through the vacuum degassing process, which is of great significance for improving the purity of titanium alloys and optimizing the subsequent processing performance. Under the heating condition of 100 - 400 °C, vacuum treatment is carried out. Through sufficient thermal driving action, the adsorbed gases on the powder surface and the residual gases in the internal micro-pores are effectively removed, significantly reducing the gas content in the material. This process combines a low-vacuum environment (below 1 Pa) with heating conditions, enabling gas impurities, including harmful gases such as oxygen, hydrogen, and nitrogen, to rapidly escape from the powder. This process not only improves the purity of the powder but also reduces the oxygen content of the material, preventing the formation of oxide inclusions. Vacuum-sealed welding is another major highlight of this process. After degassing, the envelope is efficiently sealed and welded, completely isolating the entry of the external atmosphere, ensuring the high purity of the material during subsequent high-temperature processes. It not only improves the vacuum holding capacity but also avoids further reactions of titanium with external impurities such as oxygen and nitrogen, thereby ensuring the chemical stability and purity of the material. By combining vacuum degassing and sealed envelope technologies, the oxygen content of the titanium alloy profile is effectively controlled to ≤0.2 wt.%. The low oxygen content reduces the formation of oxide inclusions, significantly enhancing the toughness and ductility of the material.

[0098] Through the envelope extrusion technology of the present invention, the density of the titanium alloy profile reaches 100%, eliminating the material pores and greatly improving the mechanical strength and fatigue performance of the titanium alloy. The pre-sintered fine-grained billet is densified by extrusion forming, and by controlling the extrusion ratio, the grain size of the titanium alloy is further refined, with the average grain size being less than or equal to 20 μm. The fine grains significantly improve the mechanical properties of the material, including yield strength, tensile strength, and toughness. Grain refinement also enhances the high-temperature performance of the material, enabling it to have excellent creep and fatigue resistance in high-temperature environments. In addition, the uniform grain distribution avoids the generation of local weaknesses, contributing to the improvement of the reliability and service life of the material.

[0099] By integrating vibration powder filling, degassing, sintering, and extrusion forming into an integrated process, the present invention significantly shortens the process flow and remarkably reduces the cumbersome steps in the traditional process. For example, by introducing vibration powder filling technology, the tap density is effectively increased during the powder filling process, reducing the voids between the powders and greatly improving the uniformity of the material and the quality of the final product. And the extrusion forming is directly carried out using the high-temperature heat of the pre-sintered billet, eliminating the secondary heating and extrusion process of the traditional sintered billet. This integrated process design not only saves time but also improves the overall production efficiency.

[0100] In summary, compared with the traditional powder metallurgy hot isostatic pressing for preparing titanium alloys that requires removing the cladding, the present invention has successfully overcome the limitations of the traditional hot isostatic pressing + hot extrusion process through the innovative powder metallurgy titanium alloy cladding extrusion technology, providing an efficient and reliable solution for the preparation and processing of titanium alloy materials. With the design of a titanium or titanium alloy cladding with consistent composition as the core, combined with optimized vacuum degassing, sealed welding, and low-temperature pre-sintering technologies, remarkable results have been achieved in aspects such as material densification, grain refinement, and impurity control. By enhancing the strength and stability of the billet through cladding protection, cracking and deformation during the processing have been effectively prevented, the problem of powder contamination has been isolated, and at the same time, vacuum low-temperature sintering enables the metallurgical bonding of powder particles and has a fine-grained structure, providing a reliable guarantee for the production of high-performance titanium alloy profiles. The density of the extruded titanium alloy profiles is 100%, the grain size is controlled within 20 μm, and the oxygen content is ≤ 0.2 wt.%, showing excellent mechanical properties and chemical stability. In addition, the integrated one-piece forming process simplifies the traditional process, significantly improves the production efficiency and product quality, opens up a new path for the preparation of high-performance titanium alloys in fields such as aerospace and medical devices, and demonstrates broad application prospects and industrial value.

[0101] It should be understood that the term "and / or" in this text is merely a description of the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. Here, A and B can be singular or plural. In addition, the character " / " in this text generally represents an "or" relationship between the associated objects before and after, but it may also represent an "and / or" relationship, which can be specifically understood by referring to the context before and after.

[0102] In the present invention, "at least one" means one or more, and "a plurality" means two or more. "At least one of the following" or its similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c can represent: a, b, c, a - b, a - c, b - c, or a - b - c, where a, b, and c can be single or multiple.

[0103] It should be understood that in various embodiments of the present invention, the magnitude of the sequence numbers of the above processes does not mean the order of execution. The order of execution of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.

[0104] As described above, it is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the said claims.

Claims

1. A method for preparing a powder metallurgy titanium alloy by canned extrusion, characterized in that The method for preparing a powder metallurgy titanium alloy by envelope extrusion comprises the following steps: S1. Envelope preparation: Select a material with the same composition as the powder metallurgy titanium alloy raw material powder as the envelope material. Seal the bottom of the envelope, and provide a feeding port at the top of the envelope. A valve for controlling the feeding of the feeding port is arranged on the feeding port. S2. Vibration powder filling: Open the valve in S1, pour the powder metallurgy titanium alloy raw material powder into the envelope in S1, and apply vibration to the envelope during the powder pouring process to increase the tapped density of the powder in the envelope. Stop vibrating until the raw material powder fills the envelope, and obtain a high-tapped powder-containing envelope. S3. Heating and degassing: Heat and evacuate the powder-containing envelope in S2. Close the valve when the vacuum degree in the envelope is reduced to less than 1 Pa, and obtain a vacuum powder-containing envelope. S4. Envelope sealing: Weld and seal the feeding port of the vacuum powder-containing envelope in S3 to ensure the vacuum sealing of the envelope, and then remove the feeding port valve to obtain a powder-containing envelope with a complete seal. S5. Low-temperature pre-sintering: Vertically place the powder-containing envelope in S5 into a sintering furnace with the top of the powder-containing envelope facing upward, and then perform vacuum sintering to obtain a titanium alloy pre-sintered blank with an envelope. S6. Extrusion forming: Preheat the extrusion cylinder first, then directly take out the titanium alloy pre-sintered blank in S5 from the sintering furnace without cooling, and then put it into an extruder for extrusion to obtain a high-performance titanium alloy profile.

2. The method for preparing a powder metallurgy titanium alloy by canned extrusion according to claim 1, wherein The powder metallurgy titanium alloy raw material powder in S1 is a commercially available titanium and titanium alloy powder, with a sphericity ≥ 70%, a powder particle size of 10 - 100 μm, a tapped density of the powder being 58 - 65% of the theoretical density, and an oxygen content ≤ 0.1 wt%.

3. The method for preparing a powder metallurgy titanium alloy by canned extrusion according to claim 1, characterized in that, The envelope in S1 is a cylindrical titanium can with a diameter of 100 - 1000 mm, an envelope wall thickness of 1 - 10 mm, and a height of 50 - 2000 mm. Select a suitable titanium can according to specific process requirements; the diameter of the feeding port is 10 - 50 mm, and the feeding port protrudes 20 - 100 mm above the top of the envelope.

4. The method for preparing a powder metallurgy titanium alloy by cladding extrusion according to claim 1, characterized in that, The vibration frequency in S2 is 10 - 500 Hz. After vibration stops, the tapped density of the powder in the envelope is 61 - 75% of the theoretical density, which is 5 - 15% higher than the tapped density of the powder in S1.

5. The method for preparing a powder metallurgy titanium alloy by sheath extrusion according to claim 1, characterized in that, The heating rate in S3 is 1 - 5 °C / min, the temperature is 100 - 400 °C, and the holding time is 30 - 120 min.

6. The method for preparing a powder metallurgy titanium alloy by cladding extrusion according to claim 1, wherein, The composition of the welding wire in S4 is the same as that of the powder metallurgy titanium alloy raw material powder in S1.

7. The method for preparing a powder metallurgy titanium alloy by canned extrusion according to claim 1, characterized in that, The temperature of vacuum sintering in S5 is 980 - 1100 °C, the heat preservation time is 2 - 5 h, the vacuum degree is 10 -1 -10 -3 Pa, and the sintering density of the titanium alloy pre-sintered blank with a jacket is 75 - 85%.

8. The method for preparing a powder metallurgy titanium alloy by sheath extrusion according to claim 1, wherein, The preheating temperature of the extrusion cylinder in S6 is 300 - 500 °C, and the holding time is 0.5 - 1.5 h; the pre-sintered blank is directly taken out from the sintering furnace without cooling, the blank temperature is 900 - 1080 °C, the extrusion ratio is 10 - 100, and the extrusion rate is 50 - 200 mm / s.

9. The method for preparing a powder metallurgy titanium alloy by canned extrusion according to claim 1, characterized in that, The shapes of high-performance titanium alloy profiles in S6 include rod-shaped, square-shaped, tubular and irregular shapes. The shape, size and specifications of the profiles are determined by the extrusion die, extrusion ratio and weight of the extrusion billet. The tensile strength of the titanium alloy profiles is 10-30% higher than that of hot isostatic pressing and 10-20% higher than that of hot extrusion. The elongation of the titanium alloy profiles is 5-15% higher than that of hot isostatic pressing and 5-10% higher than that of hot extrusion. The high-cycle fatigue strength of the titanium alloy profiles is more than 30% higher than that of hot isostatic pressing and 10-20% higher than that of hot extrusion.

10. The method for preparing a powder metallurgy titanium alloy by canned extrusion according to claim 1, wherein, The canned extrusion technology described in S1-S6 is applicable not only to titanium and titanium alloys, but also to iron-based alloys, copper alloys, aluminum alloys and superalloys.

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