Method for preparing high-toughness titanium alloy based on high-oxygen powder

Abstract

The invention provides a method for preparing a high-toughness titanium alloy based on high-oxygen powder, and relates to the technical field of powder metallurgy titanium alloys. The method sequentially comprises the steps of preparation of a mixed oxidation medium, oxidation of the mixed oxidation medium, cold isostatic pressing forming of a titanium alloy pressed blank, vacuum sintering preparation of a titanium alloy sintered blank, hot working deformation of the titanium alloy sintered blank, cyclic thermal deformation of TC4 titanium alloy and primary solution treatment of fine-grain TC4 titanium alloy. And the high-oxygen TC4 titanium alloy is subjected to multiple times of circulating solution treatment and multiple times of circulating aging treatment. According to the invention, the tensile strength of the medium-strength high-oxygen TC4 titanium alloy is obviously improved from less than or equal to 1200 MPa to a high-strength range (more than or equal to 1350 MPa); the method is simple and easy to operate, high in flexibility, simple to operate, wide in application and beneficial to industrial large-scale production and popularization, and the tolerance of the titanium alloy to the oxygen content is improved.

Description

Technical Field

[0001] The invention relates to the technical field of powder metallurgy titanium alloys, and in particular to a method for preparing high-strength and high-toughness titanium alloys based on high-oxygen powder. Background Art

[0002] Titanium alloys have been widely used in aerospace, medical devices and automotive industries due to their excellent mechanical properties and corrosion resistance. However, the sensitivity of titanium alloys to oxygen content is generally considered to be a key limiting factor in the preparation of high-performance titanium alloys. Traditionally, oxygen content exceeding 0.33wt.% will increase the brittleness of the material and reduce ductility, limiting the potential of titanium alloys in high-strength and high-toughness applications. However, oxygen, as an interstitial strengthening element, can actually play a significant strengthening role in titanium alloys. How to use high-oxygen content titanium powder to prepare high-strength and high-toughness titanium alloys has become a technical problem that needs to be broken through.

[0003] The prior art generally adopts the following methods to solve the problem of high oxygen content in titanium alloys: First, by using titanium powder with low oxygen content or using vacuum deoxidation technology during the smelting process to reduce the oxygen content to improve the ductility of titanium alloys. Although this method can reduce the brittleness of the material to a certain extent, it often requires high-cost process control, and reducing the oxygen content may sacrifice the solid solution strengthening effect of the material and affect the strength of the titanium alloy. Secondly, by adding deoxidizing elements such as calcium, magnesium, and yttrium, these elements can form stable compounds with oxygen, thereby suppressing the brittleness of the titanium alloy. Or, as in Chinese patent CN118222882A, titanium alloy powder is mixed with medium-high entropy alloy powder by laser melting and heat treatment. However, these methods increase production costs, and the oxides that may be introduced may lead to microstructural inhomogeneity, which may cause fluctuations in mechanical properties.

[0004] There are also multiple low-temperature forgings to reduce the impact of oxide inclusions on the plasticity of the material. Although this method can reduce the risk of microcracks caused by oxygen, it has low production efficiency, high cost, and it is not easy to ensure product consistency. There are also strengthening alloy elements such as iron, copper, and chromium to compensate for the loss of ductility caused by high oxygen content. However, this not only increases the complexity of the alloy composition, but also requires complex phase transformation and microstructure control, which also increases the process difficulty and cost.

[0005] In addition, Chinese patent CN112725713A discloses a high-strength, high-plasticity powder metallurgy titanium alloy and a processing method thereof. The oxygen content of the ingot prepared by powder metallurgy does not exceed 0.4wt%. Although a heterogeneous layered multi-level second phase structure with improved strength, plasticity and toughness can be obtained through three-upsetting and three-drawing forging, three-upsetting and three-drawing forging, bar rolling and annealing heat treatment, cracks are prone to occur during the forging process, and the forging cost is high and the efficiency is low.

[0006] The oxygen content of the high-oxygen TC4 titanium alloy powder in Chinese patent CN111360276A is not high, less than 0.4wt%, and the addition of rare earth elements will increase the preparation cost of the material. The mechanical properties of the prepared material are not high, the elongation is high, and the synergistic improvement of strength, plasticity and toughness cannot be achieved.

[0007] In Chinese patent CN114752818A, a nanostructured aluminum alloy composite material is toughened by a titanium alloy lattice structure. The lattice structure needs to be prepared first, and then the aluminum-based amorphous alloy powder is placed in the pores of the titanium alloy lattice structure, cold pressed, and hot extruded to obtain the composite material. The titanium alloy lattice structure and the nanostructured aluminum alloy need to be prepared, which will lead to high costs. How the subsequent aluminum-based amorphous alloy powder is added to the pores will affect the final performance, and it is difficult to evenly distribute the composition and performance. Summary of the invention

[0008] In order to solve the limitation of the prior art that titanium alloys have poor material plasticity, brittle fracture, low oxygen tolerance, low service life and difficulty in recycling residual titanium due to oxygen sensitivity, the negative impact of oxygen is mainly avoided by reducing the oxygen content or introducing specific alloying elements, multiple forging, thermal deformation, heat treatment, and lattice structure. These methods often lead to high costs, complex processes and unstable performance, and do not consider technical problems such as how to fully utilize the potential of oxygen as a gap strengthening element. The present invention proposes a method for preparing high-strength and tough titanium alloys based on high-oxygen powder that can solve the above problems. The technical solution is as follows:

[0009] A method for preparing a high-strength and tough titanium alloy based on high-oxygen powder, the method for preparing a high-strength and tough titanium alloy based on high-oxygen powder comprises the following steps:

[0010] S1. Preparation of mixed oxidizing medium: using a high-precision gas mixer to precisely control the ratio of oxygen and argon to mix and obtain a mixed oxidizing medium;

[0011] S2, oxidation with mixed oxidizing medium: placing commercially available hydrogenated dehydrogenated TC4 titanium alloy powder in a rotary reactor, evacuating the furnace, then heating it, and then introducing S1 mixed oxidizing medium, controlling the oxidation time, and slowly rotating the reactor. After the oxidation is completed, stop introducing the oxidizing medium, and cool it to room temperature with the furnace to obtain high-oxygen TC4 titanium alloy powder;

[0012] S3, cold isostatic pressing of titanium alloy blanks: the high oxygen TC4 titanium alloy powder in S2 is loaded into a cold isostatic pressing package, the titanium alloy powder in the package is compacted by vibration, and the package is sealed by a vacuum sealing device, and the sealed package is placed in a cold isostatic pressing device, and the pressure is gradually increased to the required pressure and maintained, and after demolding, a high oxygen TC4 titanium alloy blank is obtained;

[0013] S4, vacuum sintering preparation of titanium alloy sintered blank: put the S4 medium oxygen TC4 titanium alloy pressed blank into a vacuum sintering furnace for vacuum sintering, control the vacuum degree and sintering temperature, and after sintering, cool it to room temperature with the furnace to obtain a high oxygen TC4 titanium alloy sintered blank;

[0014] S5. Hot working deformation of titanium alloy sintered billet: The S4 medium-high oxygen TC4 titanium alloy sintered billet is placed in a resistance heating furnace. 1 The TC4 titanium alloy is obtained by heat preservation for 1-3 hours and then taken out and subjected to hot working deformation by forging, extrusion or rolling.

[0015] Cyclic thermal deformation of S6 and TC4 titanium alloys: The TC4 titanium alloy in S5 is repeatedly subjected to the thermal deformation of S5 for multiple passes, and the heating temperature T n Than the previous heating temperature T n-1 Low, and finally fine-grained TC4 titanium alloy is obtained;

[0016] S7, a solid solution treatment of fine-grained TC4 titanium alloy: a solid solution treatment is performed on the fine-grained TC4 titanium alloy in S6, followed by direct water cooling to obtain a solid solution high-oxygen TC4 titanium alloy;

[0017] S8, multiple cycles of solid solution treatment of high oxygen TC4 titanium alloy: the single solid solution high oxygen TC4 titanium alloy in S7 is subjected to multiple cycles of heat treatment of S7 to obtain a multiple cycles of high oxygen TC4 titanium alloy;

[0018] S9. Aging treatment of multiple-cycle high-oxygen TC4 titanium alloy: Aging treatment is performed on the multiple-cycle high-oxygen TC4 titanium alloy in S8, and high-strength and tough high-oxygen TC4 titanium alloy is obtained after air cooling.

[0019] Optionally, the ratio of oxygen to argon in S1 is 1:5-1:9.

[0020] Optionally, the commercially available hydrogenated dehydrogenated TC4 titanium alloy powder in S2 has a particle size of 0-20 μm, is evacuated to below 1 Pa, and then heated to 500-700°C, the oxidation time is controlled at 30-90 min, and the reactor is slowly rotated at a low speed of 5-30 rpm. The powder oxygen content of the high-oxygen TC4 titanium alloy powder is ≥0.4wt.% and ≤1.2wt.%.

[0021] Optionally, the required pressure in S3 is 150-250 MPa, the holding time is 30-200 s, and the shape of the high-oxygen TC4 titanium alloy billet is determined according to actual production, and is a slab, a slab, a tube or a shaped billet.

[0022] Optionally, the vacuum degree of vacuum sintering in S4 is 10 -1 -10 -3Pa, the sintering temperature is 1050-1200℃, and the holding time is 2-6h.

[0023] Optionally, S5 in T 1 The temperature is 1100-1250℃, the deformation of hot working deformation is 70-90%. The hot working process and shape of TC4 titanium alloy are determined according to the target product.

[0024] Optionally, the number of times the hot working deformation of S5 is repeated in S6 is 2-5 times, which is n Keep warm for 30min, T n =T n-1 -T 0 , n=2,3,4,5,T n ≥900℃,T 0 The heat treatment process is carried out at a temperature of 50-100°C, and the heating temperature is 50-100°C lower than the heating temperature of the previous pass. The deformation amount of hot working deformation is 70-90%. The hot working pass is determined according to the maximum grain size of the TC4 titanium alloy. The maximum grain size of the fine-grained TC4 titanium alloy is ≤10μm. The oxygen content of the TC4 titanium alloy is greater than 0.4wt.% and less than 1.4wt.%.

[0025] Optionally, the temperature of the first solution treatment in S7 is 920-1020° C., and the holding time is 5-30 min.

[0026] Optionally, the number of cycles of the multiple-cycle heat treatment of S7 in S8 is 2-10 times, and the number of cycles is determined by the oxygen content of the titanium alloy; when the oxygen content is greater than 0.8wt.%, the number of cycles is ≥6 times.

[0027] Optionally, the aging treatment temperature in S9 is 480-620°C, the aging time is 3-10h, the oxygen content of the high-strength and high-toughness high-oxygen TC4 titanium alloy is >0.4wt.% and <1.4wt.%, the density is 99.9-100%, the tensile strength is ≥1350MPa, the yield strength is ≥1250MPa, the yield strength ratio is >0.9, and the elongation is ≥7%.

[0028] Optionally, the methods described in S1-S9 are not limited to the preparation of high-oxygen TC4 alloy, but are also applicable to other α, α+β titanium alloys and their waste recycling.

[0029] Technical principle of the present invention:

[0030] The existing methods to avoid oxygen embrittlement are generally to add alloying elements such as Ca, Mg, Re, high-temperature oxygen fixation, or to reduce the oxygen content in the titanium matrix at high cost, but the effect is limited, and there are technical defects such as complex process, high cost, and inability to guarantee product performance.

[0031] The present invention proposes a new method for preparing high-oxygen, high-strength and high-toughness titanium alloy based on thermomechanical treatment, heat treatment and oxygen element regulation. By artificially introducing and making full use of the excellent characteristics of interstitial oxygen, the effective distribution and strengthening effect of oxygen in the titanium alloy are achieved. The high-oxygen TC4 titanium alloy achieves high strength and high plasticity matching, and its tensile strength is ≥1350MPa and elongation is ≥7%. Compared with the traditional process.

[0032] The present invention achieves solid solution strengthening of the titanium alloy by precisely controlling the oxygen element through cyclic thermomechanical treatment and cyclic heat treatment. Under the premise of ensuring the strong plasticity of the material, it solves the problems of high oxygen removal cost, complex process and oxygen embrittlement in the traditional titanium alloy preparation process. The titanium alloy material finally prepared has excellent strength (≥1350MPa) and good plasticity (elongation ≥7%).

[0033] The present invention proposes to use a high-precision gas mixer to mix oxygen and argon in an accurate proportion to ensure the accuracy and uniformity of the oxygen concentration. The mixed oxygen-argon medium is introduced into a rotary reactor. The uniform high-oxygen powder is beneficial to the subsequent process oxygen regulation to achieve the strength-plasticity matching of the titanium alloy and reduce the oxygen sensitivity. This is essentially different from the traditional process method.

[0034] The invention adopts a cyclic high-temperature hot processing deformation technology to realize the processing deformation of a high-oxygen titanium alloy sintered blank.

[0035] The present invention realizes effective processing of high-oxygen titanium alloy sintered billets through cyclic high-temperature hot processing technology, and adopts a gradually decreasing hot processing temperature strategy to achieve grain refinement. The processing temperature after each thermal deformation is lower than that of the previous pass, thereby avoiding abnormal grain growth caused by recovery recrystallization, and gradually reducing the flow inside the grains, thereby increasing deformation storage energy. At the same time, the process promotes the recrystallization process, effectively adjusts the dislocation structure inside the grains, and thus achieves the purpose of grain refinement. The present invention further prevents grain growth by shortening the holding time while maintaining sufficient rheological resistance reduction.

[0036] The present invention designs a cyclic solution heat treatment process according to the interstitial oxygen content, optimizes and controls the chemical composition and microstructure of the titanium alloy, combines oxygen elements with dislocations to induce them to serve as nucleation points, produces a multifunctional martensitic structure, and utilizes nano-twinned martensite and martensitic twins to jointly release the stress of the deformation process.

[0037] The present invention proposes a cyclic solution treatment + water cooling treatment and designs a TC4 multifunctional martensite heterostructure. Under the stress stimulation of the surrounding multifunctional martensite and the stimulation of its own high oxygen content, the α phase promotes the HCP-FCC phase transformation, thereby ensuring the high plasticity of the material and realizing the preparation of a high-oxygen and high-strength and tough titanium alloy.

[0038] This method does not require the additional addition of alloying elements such as Fe, Cu, Cr, Mo, Zr, Nb, and Ta. By making full use of the high oxygen content in the titanium alloy powder and finely controlling the oxygen element, the brittleness problem caused by oxygen is avoided, thereby effectively improving the strength and toughness of the titanium alloy.

[0039] The present invention obtains a high-oxygen TC4 alloy with uniform composition, dense structure and fine grains through cyclic heat treatment combined with subsequent aging treatment. The oxygen element is used to induce the formation of multifunctional martensite to achieve high plasticity control, and the solid solution strengthening effect of the oxygen element is fully utilized to finally obtain a high-strength and tough high-oxygen TC4 titanium alloy with a tensile strength of ≥1350MPa and an elongation of ≥7%, showing excellent mechanical properties.

[0040] The present invention breaks the tolerance of titanium alloy to oxygen content, increases its oxygen content from 0.3wt.% to 1.4wt.%, significantly enhances the specific strength of the alloy, broadens the application prospects of titanium alloy in aerospace, high-performance equipment and other fields, and provides a new technical path for the high strength and toughness of titanium alloy.

[0041] The present invention is not limited to improving the oxygen tolerance of high-oxygen TC4 alloy, but is also applicable to improving the strength, toughness and oxygen tolerance of other α, α+β series titanium alloys such as Ti-2.5Cu, Ti-5Al-2.5Sn, Ti-6Al-2Nb-1Ta-0.8Mo, Ti-10V-2Fe-3Al and Ti-15Mo-3Nb-3Al.

[0042] In summary, the high-oxygen titanium alloy proposed in the present invention combines cyclic high-temperature thermal deformation technology with heat treatment to achieve the preparation of high-strength and high-oxygen TC4 titanium alloy. Through multiple thermomechanical treatments, cyclic solution treatments and efficient aging treatments, the oxygen element regulation of the high-oxygen TC4 titanium alloy is achieved, and the tolerance of the titanium alloy to oxygen content is expanded. It is highly flexible, simple to operate, and widely applicable, and is suitable for low-cost and high-efficiency industrial production of titanium alloys.

[0043] Compared with the prior art, the above technical solution has at least the following beneficial effects:

[0044] The above scheme, the present invention proposes a method for preparing high-strength and toughness titanium alloy based on high-oxygen powder, which can solve the limitations of the prior art that titanium alloys have poor material plasticity, brittle fracture, low oxygen tolerance, low service life and difficulty in recycling residual titanium due to oxygen sensitivity. The negative impact of oxygen is mainly avoided by reducing the oxygen content or introducing specific alloy elements, multiple forging, thermal deformation, heat treatment, and lattice structure. These methods often lead to high costs, complex processes and unstable performance, and do not consider technical issues such as how to fully utilize the potential of oxygen as a gap strengthening element.

[0045] Through innovative process design, the present invention significantly improves the tolerance of titanium alloy to oxygen, greatly reduces the inherent oxygen sensitivity and oxygen brittleness of the titanium matrix, significantly improves the strength and specific strength of the titanium alloy, and has strong industrial applicability.

[0046] The present invention ensures that the oxidizing medium can be evenly distributed by slowly rotating the reaction furnace at a low speed, so as to provide a stable oxidizing environment and avoid brittleness of the powder caused by local oxidation transition.

[0047] The present invention avoids technical defects such as internal cracks caused by local uneven deformation and excessive deformation through multiple thermal deformations, and introduces abundant dislocations by utilizing multiple deformations to achieve dislocation pinning, thereby significantly enhancing the strength and toughness of the titanium alloy.

[0048] The present invention ensures the grain refinement effect by means of cyclic high-temperature hot processing, lower processing temperature after each hot deformation than the previous process, shortening the holding time, etc., thereby achieving a significant fine grain strengthening effect with a grain size of ≤10μm and ensuring the high strength and toughness of the high-oxygen titanium alloy.

[0049] The present invention effectively avoids high oxygen brittleness and makes full use of its solid solution strengthening characteristics by designing a cyclic solution heat treatment process and optimizing the composition and microstructure, thereby greatly increasing the strength of the titanium alloy, achieving a synergistic improvement in the strength and plasticity of the titanium alloy, and ensuring the consistency and stability of product quality.

[0050] In addition, the present invention increases the tolerance limit of oxygen in titanium alloys from 0.3wt.% of traditional TC4 to 1.4wt.%, effectively reducing the difficulty of utilizing high-oxygen titanium alloys, providing broader application prospects for titanium alloy manufacturing fields such as titanium alloy strengthening, titanium powder recovery, powder metallurgy, and injection molding, and greatly expanding the value and potential of high-oxygen titanium alloys in practical engineering applications.

[0051] In summary, compared with other traditional methods, the method of the present invention does not require the additional addition of alloying elements such as Fe, Cu, Cr, Mo, Zr, Nb, Ta, and Y. By making full use of the high oxygen content and combining a multi-step cycle process with heat treatment, the tensile strength of the medium-strength high-oxygen TC4 titanium alloy is significantly increased from (≤1200MPa) to the high-strength range (≥1350MPa). The method is simple and easy to operate, which expands the tolerance of titanium alloys to oxygen content. It is highly flexible, simple to operate, and widely applicable, which is conducive to large-scale industrial production and promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0053] Figure 1 The present invention is a process flow chart of a method for preparing high-strength and toughness titanium alloy based on high-oxygen powder. DETAILED DESCRIPTION

[0054] The technical solution of the present invention is described below in conjunction with the accompanying drawings.

[0055] In the embodiments of the present invention, words such as "exemplarily" and "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "example" in the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of the word "example" is intended to present the concept in a specific way. In addition, in the embodiments of the present invention, the meaning expressed by "and / or" can be both, or it can be either of the two.

[0056] In the embodiments of the present invention, "image" and "picture" may sometimes be used interchangeably. It should be noted that when the distinction between them is not emphasized, the meanings they intend to express are consistent.

[0057] In the embodiments of the present invention, sometimes the subscripts such as W 1 It may be written in non-subscript form such as W1. When the difference is not emphasized, the meaning is the same.

[0058] In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0059] A method for preparing a high-strength and tough titanium alloy based on high-oxygen powder, the method for preparing a high-strength and tough titanium alloy based on high-oxygen powder is combined with Figure 1 Follow these steps:

[0060] S1. Preparation of mixed oxidizing medium: using a high-precision gas mixer to precisely control the ratio of oxygen and argon to mix and obtain a mixed oxidizing medium;

[0061] S2, oxidation with mixed oxidizing medium: placing commercially available hydrogenated dehydrogenated TC4 titanium alloy powder in a rotary reactor, evacuating the furnace, then heating it, and then introducing S1 mixed oxidizing medium, controlling the oxidation time, and slowly rotating the reactor. After the oxidation is completed, stop introducing the oxidizing medium, and cool it to room temperature with the furnace to obtain high-oxygen TC4 titanium alloy powder;

[0062] S3, cold isostatic pressing of titanium alloy blanks: the high oxygen TC4 titanium alloy powder in S2 is loaded into a cold isostatic pressing package, the titanium alloy powder in the package is compacted by vibration, and the package is sealed by a vacuum sealing device, and the sealed package is placed in a cold isostatic pressing device, and the pressure is gradually increased to the required pressure and maintained, and after demolding, a high oxygen TC4 titanium alloy blank is obtained;

[0063] S4, vacuum sintering preparation of titanium alloy sintered blank: put the S4 medium oxygen TC4 titanium alloy pressed blank into a vacuum sintering furnace for vacuum sintering, control the vacuum degree and sintering temperature, and after sintering, cool it to room temperature with the furnace to obtain a high oxygen TC4 titanium alloy sintered blank;

[0064] S5. Hot working deformation of titanium alloy sintered billet: The S4 medium-high oxygen TC4 titanium alloy sintered billet is placed in a resistance heating furnace. 1 The TC4 titanium alloy is obtained by heat preservation for 1-3 hours and then taken out and subjected to hot working deformation by forging, extrusion or rolling.

[0065] Cyclic thermal deformation of S6 and TC4 titanium alloys: The TC4 titanium alloy in S5 is repeatedly subjected to the thermal deformation of S5 for multiple passes, and the heating temperature T n Than the previous heating temperature T n-1 Low, and finally fine-grained TC4 titanium alloy is obtained;

[0066] S7, a solid solution treatment of fine-grained TC4 titanium alloy: a solid solution treatment is performed on the fine-grained TC4 titanium alloy in S6, followed by direct water cooling to obtain a solid solution high-oxygen TC4 titanium alloy;

[0067] S8, multiple cycles of solid solution treatment of high oxygen TC4 titanium alloy: the single solid solution high oxygen TC4 titanium alloy in S7 is subjected to multiple cycles of heat treatment of S7 to obtain a multiple cycles of high oxygen TC4 titanium alloy;

[0068] S9. Aging treatment of multiple-cycle high-oxygen TC4 titanium alloy: Aging treatment is performed on the multiple-cycle high-oxygen TC4 titanium alloy in S8, and high-strength and tough high-oxygen TC4 titanium alloy is obtained after air cooling.

[0069] In particular, the ratio of oxygen to argon in S1 is 1:5-1:9.

[0070] In particular, the commercially available hydrogenated dehydrogenated TC4 titanium alloy powder in S2 has a particle size of 0-20 μm, is evacuated to below 1 Pa, and then heated to 500-700°C, the oxidation time is controlled at 30-90 min, and the reactor is slowly rotated at a low speed of 5-30 rpm. The powder oxygen content of the high-oxygen TC4 titanium alloy powder is ≥0.4wt.% and ≤1.2wt.%.

[0071] In particular, the required pressure in S3 is 150-250 MPa, the holding time is 30-200 s, and the shape of the high-oxygen TC4 titanium alloy billet is determined according to actual production, and is a slab, a slab, a tube or a shaped billet.

[0072] In particular, the vacuum degree of vacuum sintering in S4 is 10 -1 -10 -3 Pa, the sintering temperature is 1050-1200℃, and the holding time is 2-6h.

[0073] In particular, S5 T 1 The temperature is 1100-1250℃, the deformation of hot working deformation is 70-90%. The hot working process and shape of TC4 titanium alloy are determined according to the target product.

[0074] In particular, the number of passes of hot working deformation in S5 repeated multiple times in S6 is 2-5 times, which is n Keep warm for 30min, T n =T n-1 -T 0 , n=2,3,4,5,T n ≥900℃,T 0 The heat treatment process is carried out at a temperature of 50-100°C, and the heating temperature is 50-100°C lower than the heating temperature of the previous pass. The deformation amount of hot working deformation is 70-90%. The hot working pass is determined according to the maximum grain size of the TC4 titanium alloy. The maximum grain size of the fine-grained TC4 titanium alloy is ≤10μm. The oxygen content of the TC4 titanium alloy is greater than 0.4wt.% and less than 1.4wt.%.

[0075] In particular, the temperature of the first solution treatment in S7 is 920-1020°C, and the holding time is 5-30 minutes.

[0076] In particular, the number of cycles of the multiple-cycle heat treatment of S7 in S8 is 2-10 times, and the number of cycles is determined by the oxygen content of the titanium alloy; when the oxygen content is greater than 0.8wt.%, the number of cycles is ≥6 times.

[0077] In particular, the aging treatment temperature in S9 is 480-620°C, the aging time is 3-10h, the oxygen content of the high-strength and high-toughness high-oxygen TC4 titanium alloy is >0.4wt.% and <1.4wt.%, the density is 99.9-100%, the tensile strength is ≥1350MPa, the yield strength is ≥1250MPa, the yield strength ratio is >0.9, and the elongation is ≥7%.

[0078] In particular, the methods described in S1-S9 are not limited to the preparation of high-oxygen TC4 alloy, but are also applicable to other α, α+β titanium alloys and their waste recycling.

[0079] Example 1

[0080] A method for preparing a high-strength and tough titanium alloy based on high-oxygen powder, the method for preparing a high-strength and tough titanium alloy based on high-oxygen powder comprises the following steps:

[0081] S1. Preparation of mixed oxidizing medium: using a high-precision gas mixer to precisely control the ratio of oxygen and argon to be 1:5 for mixing to obtain a mixed oxidizing medium;

[0082] S2. Oxidation with mixed oxidizing medium: Place commercially available 10 μm hydrogenated dehydrogenated TC4 titanium alloy powder in a rotary reactor, evacuate to below 1 Pa, then heat to 680°C, control the oxidation time to 80 min, and slowly rotate the reactor at a low speed of 20 rpm. After the oxidation is completed, stop introducing the oxidizing medium, cool to room temperature with the furnace, and obtain high-oxygen TC4 titanium alloy powder; the powder oxygen content of the high-oxygen TC4 titanium alloy powder is 1.2 wt.%;

[0083] S3, cold isostatic pressing of titanium alloy blanks: the high oxygen TC4 titanium alloy powder in S2 is loaded into a cold isostatic pressing package, the titanium alloy powder in the package is compacted by vibration, and then the package is sealed using a vacuum sealing device, and the sealed package is placed in a cold isostatic pressing device, and the pressure is gradually increased to the required pressure of 220 MPa and maintained for 100 seconds. After demolding, a high oxygen TC4 titanium alloy blank is obtained;

[0084] Vacuum sintering preparation of S4 titanium alloy sintered blank: Put the S4 medium oxygen TC4 titanium alloy pressed blank into a vacuum sintering furnace for vacuum sintering, and control the vacuum degree to 10 -2 Pa and sintering temperature are 1190℃, holding time is 5h, after sintering, the furnace is cooled to room temperature to obtain high oxygen TC4 titanium alloy sintered blank;

[0085] S5. Hot working deformation of titanium alloy sintered billet: The S4 medium-high oxygen TC4 titanium alloy sintered billet is placed in a resistance heating furnace. 1 Keep warm for 1h, T 1 The temperature is 1250°C, and then the alloy is taken out and subjected to hot working deformation by extrusion, the deformation amount of the hot working deformation is 85%, and TC4 titanium alloy is obtained;

[0086] Cyclic thermal deformation of S6 and TC4 titanium alloys: The TC4 titanium alloy in S5 was subjected to the thermal deformation of S5 for 5 times. n (T n =T n-1 -T 0 , n=2, 3, 4, 5) and then heat-treated for 30 min, and then hot-worked by extrusion with a deformation of 90%, and T 0The heating temperature is 50°C, that is, the heating temperature is 50°C lower than the heating temperature of the previous pass, and finally a fine-grained TC4 titanium alloy is obtained; the maximum grain size of the fine-grained TC4 titanium alloy is 5μm, and the hot working pass is determined according to the maximum grain size of the TC4 titanium alloy;

[0087] S7, a solid solution treatment of fine-grained TC4 titanium alloy: a solid solution treatment is performed on the fine-grained TC4 titanium alloy in S6, the temperature of the solid solution treatment is 980°C, and the holding time is 15 minutes; then it is directly water-cooled to obtain a solid solution high-oxygen TC4 titanium alloy;

[0088] S8, multiple cycles of solid solution treatment of high oxygen TC4 titanium alloy: the single solid solution high oxygen TC4 titanium alloy in S7 is subjected to 9 cycles of heat treatment of S7 to obtain a 9 cycles high oxygen TC4 titanium alloy;

[0089] S9. Aging treatment of multiple-cycle high-oxygen TC4 titanium alloy: The multiple-cycle high-oxygen TC4 titanium alloy in S8 was subjected to aging treatment. The aging treatment temperature was 600°C, the aging time was 7h, and high-strength and tough high-oxygen TC4 titanium alloy was obtained after air cooling.

[0090] Example 2

[0091] A method for preparing a high-strength and tough titanium alloy based on high-oxygen powder, the method for preparing a high-strength and tough titanium alloy based on high-oxygen powder comprises the following steps:

[0092] S1. Preparation of mixed oxidizing medium: using a high-precision gas mixer to precisely control the ratio of oxygen and argon to be 1:7 for mixing to obtain a mixed oxidizing medium;

[0093] S2. Oxidation with mixed oxidizing medium: Place commercially available 15 μm hydrogenated dehydrogenated TC4 titanium alloy powder in a rotary reactor, evacuate to below 1 Pa, then heat to 620°C, control the oxidation time to 60 min, and slowly rotate the reactor at a low speed of 15 rpm. After the oxidation is completed, stop introducing the oxidizing medium, cool to room temperature with the furnace, and obtain high-oxygen TC4 titanium alloy powder; the powder oxygen content of the high-oxygen TC4 titanium alloy powder is 0.7 wt.%;

[0094] S3, cold isostatic pressing of titanium alloy blanks: the high oxygen TC4 titanium alloy powder in S2 is loaded into a cold isostatic pressing package, the titanium alloy powder in the package is compacted by vibration, and then the package is sealed using a vacuum sealing device, and the sealed package is placed in a cold isostatic pressing device, and the pressure is gradually increased to the required pressure of 190 MPa and maintained for 120 seconds. After demolding, a high oxygen TC4 titanium alloy blank is obtained;

[0095] Vacuum sintering preparation of S4 titanium alloy sintered blank: Put the S4 medium oxygen TC4 titanium alloy pressed blank into a vacuum sintering furnace for vacuum sintering, and control the vacuum degree to 10 -2Pa and sintering temperature are 1160℃, holding time is 3h, after sintering, the furnace is cooled to room temperature to obtain high oxygen TC4 titanium alloy sintered blank;

[0096] S5. Hot working deformation of titanium alloy sintered billet: The S4 medium-high oxygen TC4 titanium alloy sintered billet is placed in a resistance heating furnace. 1 Keep warm for 1.5h, T 1 The temperature is 1200°C, and then the alloy is taken out and hot-worked by forging, with the deformation amount of the hot-work deformation being 90%, to obtain TC4 titanium alloy.

[0097] Cyclic thermal deformation of S6 and TC4 titanium alloys: The TC4 titanium alloy in S5 was subjected to the thermal deformation of S5 for three times. n (T n =T n-1 -T 0 , n=2, 3, 4, 5) and then heat-treated for 30 min, hot working deformation was performed by forging, the deformation amount was 90%, and T 0 The heating temperature is 60°C, that is, the heating temperature is 60°C lower than the heating temperature of the previous pass, and finally a fine-grained TC4 titanium alloy is obtained; the maximum grain size of the fine-grained TC4 titanium alloy is 7μm, and the hot working pass is determined according to the maximum grain size of the TC4 titanium alloy;

[0098] S7, a solid solution treatment of fine-grained TC4 titanium alloy: a solid solution treatment is performed on the fine-grained TC4 titanium alloy in S6, the temperature of the solid solution treatment is 940°C, and the holding time is 20 minutes; then it is directly water-cooled to obtain a solid solution high-oxygen TC4 titanium alloy;

[0099] S8, multiple cycles of solid solution treatment of high oxygen TC4 titanium alloy: the single solid solution high oxygen TC4 titanium alloy in S7 is subjected to five cycles of heat treatment of S7 to obtain a five-cycle high oxygen TC4 titanium alloy;

[0100] S9. Aging treatment of multiple-cycle high-oxygen TC4 titanium alloy: The multiple-cycle high-oxygen TC4 titanium alloy in S8 was subjected to aging treatment. The aging treatment temperature was 580°C, the aging time was 5h, and high-strength and tough high-oxygen TC4 titanium alloy was obtained after air cooling.

[0101] Example 3

[0102] A method for preparing a high-strength and tough titanium alloy based on high-oxygen powder, the method for preparing a high-strength and tough titanium alloy based on high-oxygen powder comprises the following steps:

[0103] S1. Preparation of mixed oxidizing medium: using a high-precision gas mixer to precisely control the ratio of oxygen and argon to be 1:9 for mixing to obtain a mixed oxidizing medium;

[0104] S2. Oxidation with mixed oxidizing medium: Place commercially available 20 μm hydrogenated dehydrogenated TC4 titanium alloy powder in a rotary reactor, evacuate to below 1 Pa, then heat to 560°C, control the oxidation time to 50 min, and slowly rotate the reactor at a low speed of 10 rpm. After the oxidation is completed, stop introducing the oxidizing medium, cool to room temperature with the furnace, and obtain high-oxygen TC4 titanium alloy powder; the powder oxygen content of the high-oxygen TC4 titanium alloy powder is 0.5wt.%;

[0105] S3, cold isostatic pressing of titanium alloy blanks: the high oxygen TC4 titanium alloy powder in S2 is loaded into a cold isostatic pressing package, the titanium alloy powder in the package is compacted by vibration, and then the package is sealed using a vacuum sealing device, and the sealed package is placed in a cold isostatic pressing device, and the pressure is gradually increased to the required pressure of 180 MPa and maintained for 130 seconds. After demolding, a high oxygen TC4 titanium alloy blank is obtained;

[0106] Vacuum sintering preparation of S4 titanium alloy sintered blank: Put the S4 medium oxygen TC4 titanium alloy pressed blank into a vacuum sintering furnace for vacuum sintering, and control the vacuum degree to 10 -2 Pa and sintering temperature are 1130℃, holding time is 5h, after sintering, the furnace is cooled to room temperature to obtain high oxygen TC4 titanium alloy sintered blank;

[0107] S5. Hot working deformation of titanium alloy sintered billet: The S4 medium-high oxygen TC4 titanium alloy sintered billet is placed in a resistance heating furnace. 1 Keep warm for 3h, T 1 The temperature is 1100°C, and then the alloy is taken out and subjected to hot working deformation by extrusion, with the deformation amount of the hot working deformation being 70%, thereby obtaining TC4 titanium alloy;

[0108] Cyclic thermal deformation of S6 and TC4 titanium alloys: The TC4 titanium alloy in S5 was subjected to the thermal deformation of S5 for two times. n (T n =T n-1 -T 0 , n=2, 3, 4, 5) and then heat-treated for 30 min, and then hot-worked by extrusion with a deformation of 90%, and T 0 The heating temperature is 80°C, that is, the heating temperature is 80°C lower than the heating temperature of the previous pass, and finally a fine-grained TC4 titanium alloy is obtained; the maximum grain size of the fine-grained TC4 titanium alloy is 9μm, and the hot working pass is determined according to the maximum grain size of the TC4 titanium alloy;

[0109] S7, a solid solution treatment of fine-grained TC4 titanium alloy: a solid solution treatment is performed on the fine-grained TC4 titanium alloy in S6, the temperature of the solid solution treatment is 920°C, and the holding time is 30 minutes; then it is directly water-cooled to obtain a solid solution high-oxygen TC4 titanium alloy;

[0110] S8, multiple cycles of solid solution treatment of high oxygen TC4 titanium alloy: the single solid solution high oxygen TC4 titanium alloy in S7 is subjected to a double cycle heat treatment of S7 to obtain a double cycle high oxygen TC4 titanium alloy;

[0111] S9. Aging treatment of multiple-cycle high-oxygen TC4 titanium alloy: The multiple-cycle high-oxygen TC4 titanium alloy in S8 was subjected to aging treatment. The aging treatment temperature was 550°C, the aging time was 8 hours, and high-strength and tough high-oxygen TC4 titanium alloy was obtained after air cooling.

[0112] Example 4

[0113] A method for preparing a high-strength and tough titanium alloy based on high-oxygen powder, the method for preparing a high-strength and tough titanium alloy based on high-oxygen powder comprises the following steps:

[0114] S1. Preparation of mixed oxidizing medium: using a high-precision gas mixer to precisely control the ratio of oxygen and argon to be 1:6 for mixing to obtain a mixed oxidizing medium;

[0115] S2. Oxidation with mixed oxidizing medium: Place commercially available 15 μm hydrogenated dehydrogenated TC4 titanium alloy powder in a rotary reactor, evacuate to below 1 Pa, then heat to 650°C, control the oxidation time to 60 min, and slowly rotate the reactor at a low speed of 20 rpm. After the oxidation is completed, stop introducing the oxidizing medium, cool to room temperature with the furnace, and obtain high-oxygen TC4 titanium alloy powder; the powder oxygen content of the high-oxygen TC4 titanium alloy powder is 0.6 wt.%;

[0116] S3, cold isostatic pressing of titanium alloy blanks: the high oxygen TC4 titanium alloy powder in S2 is loaded into a cold isostatic pressing package, the titanium alloy powder in the package is compacted by vibration, and then the package is sealed using a vacuum sealing device, and the sealed package is placed in a cold isostatic pressing device, and the pressure is gradually increased to the required pressure of 180 MPa and maintained for 200 seconds. After demolding, a high oxygen TC4 titanium alloy blank is obtained;

[0117] Vacuum sintering preparation of S4 titanium alloy sintered blank: Put the S4 medium oxygen TC4 titanium alloy pressed blank into a vacuum sintering furnace for vacuum sintering, and control the vacuum degree to 10 -1 Pa and sintering temperature are 1150℃, holding time is 4h, after sintering, the furnace is cooled to room temperature to obtain high oxygen TC4 titanium alloy sintered blank;

[0118] S5. Hot working deformation of titanium alloy sintered billet: The S4 medium-high oxygen TC4 titanium alloy sintered billet is placed in a resistance heating furnace. 1 Keep warm for 2h, T 1The temperature is 1150°C, and then the alloy is taken out and hot-worked by forging, with the deformation amount of hot-work deformation being 90%, to obtain TC4 titanium alloy.

[0119] Cyclic thermal deformation of S6 and TC4 titanium alloys: The TC4 titanium alloy in S5 was subjected to the thermal deformation of S5 for two times. n (T n =T n-1 -T 0 , n=2, 3, 4, 5) and then heat-treated for 30 min, hot working deformation was performed by rolling, the deformation was 50%, and T 0 The heating temperature is 60°C, that is, the heating temperature is 60°C lower than the heating temperature of the previous pass, and finally a fine-grained TC4 titanium alloy is obtained; the maximum grain size of the fine-grained TC4 titanium alloy is 6μm, and the hot working pass is determined according to the maximum grain size of the TC4 titanium alloy;

[0120] S7, a solid solution treatment of fine-grained TC4 titanium alloy: a solid solution treatment is performed on the fine-grained TC4 titanium alloy in S6, the temperature of the solid solution treatment is 960°C, and the holding time is 10 minutes; then it is directly water-cooled to obtain a solid solution high-oxygen TC4 titanium alloy;

[0121] S8, multiple cycles of solid solution treatment of high oxygen TC4 titanium alloy: the single solid solution high oxygen TC4 titanium alloy in S7 is subjected to four cycles of heat treatment of S7 to obtain a four-cycle high oxygen TC4 titanium alloy;

[0122] S9. Aging treatment of multiple-cycle high-oxygen TC4 titanium alloy: The multiple-cycle high-oxygen TC4 titanium alloy in S8 was subjected to aging treatment. The aging treatment temperature was 600°C, the aging time was 5h, and high-strength and tough high-oxygen TC4 titanium alloy was obtained after air cooling.

[0123] The above scheme, the present invention proposes a method for preparing high-strength and toughness titanium alloy based on high-oxygen powder, which can solve the limitations of the prior art that titanium alloys have poor material plasticity, brittle fracture, low oxygen tolerance, low service life and difficulty in recycling residual titanium due to oxygen sensitivity. The negative impact of oxygen is mainly avoided by reducing the oxygen content or introducing specific alloy elements, multiple forging, thermal deformation, heat treatment, and lattice structure. These methods often lead to high costs, complex processes and unstable performance, and do not consider technical issues such as how to fully utilize the potential of oxygen as a gap strengthening element.

[0124] Through innovative process design, the present invention significantly improves the tolerance of titanium alloy to oxygen, greatly reduces the inherent oxygen sensitivity and oxygen brittleness of the titanium matrix, significantly improves the strength and specific strength of the titanium alloy, and has strong industrial applicability.

[0125] The present invention ensures that the oxidizing medium can be evenly distributed by slowly rotating the reaction furnace at a low speed, so as to provide a stable oxidizing environment and avoid brittleness of the powder caused by local oxidation transition.

[0126] The present invention avoids technical defects such as internal cracks caused by local uneven deformation and excessive deformation through multiple thermal deformations, and introduces abundant dislocations by utilizing multiple deformations to achieve dislocation pinning, thereby significantly enhancing the strength and toughness of the titanium alloy.

[0127] The present invention ensures the grain refinement effect by means of cyclic high-temperature hot processing, lower processing temperature after each hot deformation than the previous process, shortening the holding time, etc., thereby achieving a significant fine grain strengthening effect with a grain size of ≤10μm and ensuring the high strength and toughness of the high-oxygen titanium alloy.

[0128] The present invention effectively avoids high oxygen brittleness and makes full use of its solid solution strengthening characteristics by designing a cyclic solution heat treatment process and optimizing the composition and microstructure, thereby greatly increasing the strength of the titanium alloy, achieving a synergistic improvement in the strength and plasticity of the titanium alloy, and ensuring the consistency and stability of product quality.

[0129] In addition, the present invention increases the tolerance limit of oxygen in titanium alloys from 0.3wt.% of traditional TC4 to 1.4wt.%, effectively reducing the difficulty of utilizing high-oxygen titanium alloys, providing broader application prospects for titanium alloy manufacturing fields such as titanium alloy strengthening, titanium powder recovery, powder metallurgy, and injection molding, and greatly expanding the value and potential of high-oxygen titanium alloys in practical engineering applications.

[0130] In summary, compared with other traditional methods, the method of the present invention does not require the additional addition of alloying elements such as Fe, Cu, Cr, Mo, Zr, Nb, Ta, and Y. By making full use of the high oxygen content and combining a multi-step cycle process with heat treatment, the tensile strength of the medium-strength high-oxygen TC4 titanium alloy is significantly increased from (≤1200MPa) to the high-strength range (≥1350MPa). The method is simple and easy to operate, which expands the tolerance of titanium alloys to oxygen content. It is highly flexible, simple to operate, and widely applicable, which is conducive to large-scale industrial production and promotion.

[0131] It should be understood that the term "and / or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship, but it may also indicate an "and / or" relationship. Please refer to the context for specific understanding.

[0132] In the present invention, "at least one" means one or more, and "plurality" means two or more. "At least one of the following" or similar expressions refers 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 mean: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0133] It should be understood that in various embodiments of the present invention, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0134] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for preparing high-strength and high-toughness titanium alloy based on high-oxygen powder, characterized in that: The method for preparing high-strength and tough titanium alloy based on high-oxygen powder is as follows: S1. Preparation of mixed oxidizing medium: using a high-precision gas mixer to precisely control the ratio of oxygen and argon to mix and obtain a mixed oxidizing medium; S2, oxidation with mixed oxidizing medium: placing commercially available hydrogenated dehydrogenated TC4 titanium alloy powder in a rotary reactor, evacuating the furnace, then heating it, and then introducing S1 mixed oxidizing medium, controlling the oxidation time, and slowly rotating the reactor. After the oxidation is completed, stop introducing the oxidizing medium, and cool it to room temperature with the furnace to obtain high-oxygen TC4 titanium alloy powder; S3, cold isostatic pressing of titanium alloy blanks: the high oxygen TC4 titanium alloy powder in S2 is loaded into a cold isostatic pressing package, the titanium alloy powder in the package is compacted by vibration, and the package is sealed by a vacuum sealing device, and the sealed package is placed in a cold isostatic pressing device, and the pressure is gradually increased to the required pressure and maintained, and after demolding, a high oxygen TC4 titanium alloy blank is obtained; S4, vacuum sintering preparation of titanium alloy sintered blank: put the S4 medium oxygen TC4 titanium alloy pressed blank into a vacuum sintering furnace for vacuum sintering, control the vacuum degree and sintering temperature, and after sintering, cool it to room temperature with the furnace to obtain a high oxygen TC4 titanium alloy sintered blank; S5. Hot working deformation of titanium alloy sintered billet: Place the S4 medium-high oxygen TC4 titanium alloy sintered billet in a resistance heating furnace, keep it warm at T1 for 1-3 hours, then take it out and perform hot working deformation by forging, extrusion or rolling to obtain TC4 titanium alloy; Cyclic thermal deformation of S6 and TC4 titanium alloys: The TC4 titanium alloy in S5 is repeatedly subjected to the thermal deformation of S5 for multiple passes, and the heating temperature T n Than the previous heating temperature T n-1 Low, and finally fine-grained TC4 titanium alloy is obtained; S7, a solid solution treatment of fine-grained TC4 titanium alloy: a solid solution treatment is performed on the fine-grained TC4 titanium alloy in S6, followed by direct water cooling to obtain a solid solution high-oxygen TC4 titanium alloy; S8, multiple cycles of solid solution treatment of high oxygen TC4 titanium alloy: the single solid solution high oxygen TC4 titanium alloy in S7 is subjected to multiple cycles of heat treatment of S7 to obtain a multiple cycles of high oxygen TC4 titanium alloy; S9. Aging treatment of multiple-cycle high-oxygen TC4 titanium alloy: Aging treatment is performed on the multiple-cycle high-oxygen TC4 titanium alloy in S8, and high-strength and tough high-oxygen TC4 titanium alloy is obtained after air cooling.

2. The method for preparing high-strength and high-toughness titanium alloy based on high-oxygen powder according to claim 1, characterized in that: The ratio of oxygen to argon in S1 is 1:5-1:

9.

3. The method for preparing high-strength and high-toughness titanium alloy based on high-oxygen powder according to claim 1, characterized in that: The particle size of the commercially available hydrogenated dehydrogenated TC4 titanium alloy powder in S2 is 0-20μm. It is evacuated to below 1Pa and then heated to 500-700℃. The oxidation time is controlled at 30-90min, and the reactor is rotated slowly at a low speed of 5-30rpm. The powder oxygen content of the high-oxygen TC4 titanium alloy powder is ≥0.4wt.% and ≤1.2wt.%.

4. The method for preparing high-strength and high-toughness titanium alloy based on high-oxygen powder according to claim 1, characterized in that: The required pressure in S3 is 150-250MPa, and the holding time is 30-200s. The shape of the high-oxygen TC4 titanium alloy billet is determined according to actual production, and can be a slab, a slab, a tube or a special-shaped billet.

5. The method for preparing high-strength and high-toughness titanium alloy based on high-oxygen powder according to claim 1, characterized in that: The vacuum degree of vacuum sintering in S4 is 10 -1 -10 -3 Pa, the sintering temperature is 1050-1200℃, and the holding time is 2-6h.

6. The method for preparing high-strength and toughness titanium alloy based on high-oxygen powder according to claim 1, characterized in that: In S5, T1 is 1100-1250℃, and the deformation of hot working deformation is 70-90%. The hot working process and shape of TC4 titanium alloy are determined according to the target product.

7. The method for preparing high-strength and toughness titanium alloy based on high-oxygen powder according to claim 1, characterized in that: In S6, the hot working deformation of S5 is repeated for 2 to 5 times, which is n Keep warm for 30min, T n =T n-1 -T0,n=2,3,4,5,T n ≥900℃, T0 is 50-100℃; and the heating temperature is 50-100℃ lower than the heating temperature of the previous pass, the deformation amount of hot working deformation is 70-90%, and the hot working pass is determined according to the maximum grain size of TC4 titanium alloy, the maximum grain size of fine-grained TC4 titanium alloy is ≤10μm; the oxygen content of TC4 titanium alloy is >0.4wt.% and <1.4wt.%.

8. The method for preparing high-strength and high-toughness titanium alloy based on high-oxygen powder according to claim 1, characterized in that: The temperature of the first solution treatment in S7 is 920-1020°C, and the holding time is 5-30 minutes.

9. The method for preparing high-strength and toughness titanium alloy based on high-oxygen powder according to claim 1, characterized in that: The number of cycles of the multiple-cycle heat treatment of S7 in S8 is 2-10 times, and the number of cycles is determined by the oxygen content of the titanium alloy; when the oxygen content is greater than 0.8wt.%, the number of cycles is ≥6 times.

10. The method for preparing high-strength and high-toughness titanium alloy based on high-oxygen powder according to claim 1, characterized in that: The aging treatment temperature in S9 is 480-620℃, the aging time is 3-10h, the oxygen content of the high-strength and high-toughness high-oxygen TC4 titanium alloy is >0.4wt.% and <1.4wt.%, the density is 99.9-100%, the tensile strength is ≥1350MPa, the yield strength is ≥1250MPa, the yield strength ratio is >0.9, and the elongation is ≥7%.

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