31 results about "Beta titanium alloy" patented technology

The application relates to the technical field of titanium alloy and discloses a titanium alloy based on laser powder bed melting and a preparation method thereof, the titanium alloy comprises the following elements in percentage by weight: 85-93% of titanium, 4-6% of molybdenum, 2-4% of iron, 1-4% of tin, and inevitable impurities as the balance; the forming state organization of the titanium alloy prepared through laser powder bed melting technology is composed of metastable beta phase and fine and dispersed nanometer omega phase, and the size of the nanometer omega phase is 3-6 nm. The titanium alloy of the application has super-high strength and good plasticity, does not need a subsequent heat treatment process, and realizes low-cost, high-performance and short-process preparation of metastable beta titanium alloy.

The invention discloses a method for electron beam fuse additive manufacturing of a beta titanium alloy component, and belongs to the technical field of additive manufacturing. The invention aims to solve the problems of long period, low efficiency, low utilization rate, serious oxidation, obvious beta spots and poor obdurability of beta titanium alloy preparation in the prior art. The method comprises the following steps: pre-treating a printing wire and a substrate; the method comprises the following steps: establishing a three-dimensional solid model based on a target beta titanium alloy component, slicing the three-dimensional solid model to generate multi-layer two-dimensional slicing data, importing the slicing data into electron beam fuse additive manufacturing equipment, and setting a scanning path, preheating parameters and printing process parameters; and the equipment is started and vacuumized, beta titanium alloy printing is conducted according to set printing parameters and programs, all layers are completed, and the beta titanium alloy component is manufactured. The beta titanium alloy component prepared through the method is high in density, and a reliable technical approach is provided for preparation of high-performance beta titanium alloy components in the fields of aerospace and the like.

The application discloses a high-strength alpha+beta titanium alloy suitable for 500 DEG C and a preparation method thereof, which comprises Ti, Al, V, Mo, Nb, Zr and other impurity elements, and the mass percentage (wt.%) of alloy components is as follows: Al is 6.2-7.2, V is 1.5-2.5, Mo is 1.5-2.5, Nb is 0.5-1.5, Zr is 13.5-14.5, Mn is less than or equal to 0.02, C is less than or equal to 0.02, Ni is less than or equal to 0.01, Si is less than or equal to 0.20, Sn is less than or equal to 0.20, Cr is less than or equal to 0.04, O is less than or equal to 0.02, P is less than or equal to 0.01, S is less than or equal to 0.01, N is less than or equal to 0.006, and Ti is the balance. p The application realizes that the alloy has a specific microstructure of a bimodal structure composed of primary alpha phase and transformed beta phase by alloy design, the primary equiaxial alpha s The content of the secondary alpha s The width of the secondary alpha s The alpha T / beta The application forms an alpha The application has excellent thermal stability and thermal strength, and no harmful phase is generated after aging at 550 DEG C. Meanwhile, the alloy has good mechanical properties and excellent processing deformation capacity, the yield strength at room temperature is more than 1250 MPa, the tensile strength at room temperature is more than 1300 MPa, the plasticity at room temperature is more than 7%, and the tensile strength at 500 DEG C is more than 600 MPa, so the application discloses a new high-strength titanium alloy suitable for 500 DEG C.

The invention discloses a method for regulating and controlling as-cast high-toughness beta titanium alloy by introducing a triangular alpha phase of an alpha / beta coherent interface, and relates to the field of complex titanium alloy casting preparation. The method aims at solving the problems that an existing complex titanium alloy casting is low in strength and toughness, and the obdurability cannot be improved through plastic deformation. According to the method, the triangular alpha phase with the alpha / beta coherent interface is introduced into the titanium alloy by regulating and controlling the components of the beta titanium alloy and carrying out proper heat treatment, so that the purpose of coordinating the strength and toughness matching of the alloy is achieved. It is worthy of noting that the alpha phase of the triangle of the alpha / beta coherent interface is generated in the heat treatment process, and the fluidity of the titanium alloy in the casting and mold filling process of a casting cannot be affected. The tensile strength of the titanium alloy in the designed component range ranges from 1100 MPa to 1350 MPa, the toughness ranges from 50 MPa.m < 1 / 2 > to 77 MPa.m < 1 / 2 >, and the performance requirements of various complex titanium alloy structural parts can be met. The method is applied to the field of complex titanium alloy casting preparation.

The application belongs to the field of novel beta titanium alloy hot working, and particularly relates to a forging method for improving anisotropy and strength-toughness matching of super-high strength and toughness beta titanium alloy. The method comprises the following steps: homogenizing a rod, wherein the heating temperature is (Tbeta+30)~(Tbeta+100) DEG C, and high-temperature homogenization treatment is performed for 15-30 hours; high-temperature reversing upsetting and drawing forging, the heating temperature of each fire is reduced by 20-50 DEG C in turn, and the range of the heating temperature is (Tbeta+30)~(Tbeta+100) DEG C; blank forging to obtain a blank; and isothermal forging on the blank to obtain a forged piece. The beta titanium alloy forging process specification is formulated, the problem of anisotropy of TB17 titanium alloy is greatly improved, and the strength and plasticity and toughness are well matched.

This invention provides a biocompatible β This invention relates to a method for composite modification of titanium alloy surfaces, belonging to the technical field of alloy modification methods. The invention includes applications in medical... β This invention involves introducing bioactive particles onto the surface of a titanium alloy substrate, performing friction stir processing (FSP) on the substrate to introduce bioactive particles and construct a gradient grain structure, and then subjecting the FSP-treated substrate to compressed plasma flow (CPF) treatment to achieve uniform distribution of bioactive particles and construct a topology with an average surface roughness of 3-6 μm suitable for cell growth. The invention precisely controls the amount of bioactive particles introduced and constructs a gradient grain structure through friction stir processing (FSP); simultaneously, compressed plasma flow (CPF) technology achieves uniform distribution of bioactive particles and an ideal surface roughness of 3-6 μm on the titanium alloy surface. Ultimately, this significantly improves the cell adhesion, proliferation capacity, and osteogenic properties of the material surface, solving the technical problem of low integration efficiency of traditional titanium alloy implants with human bone tissue.

The application provides a near-beta titanium alloy, which comprises the following components in percentage of raw material mass: Al: 2.5-3.5 %, V: 7-9 %, Cr: 0.8-1.8 %, Mo: 0.7-1.7 %, Fe: 0.5-1.0 %, and the balance of Ti and inevitable impurities. The new high-strength and high-toughness near-beta titanium alloy can reduce the decrease of plasticity and toughness when improving the strength index, fundamentally reduces the difficulty of alloy smelting control, has the advantages of high specific strength, good fracture toughness, good hardenability and good controllability of composition, and can be used for manufacturing large equipment in the fields of aerospace, weapons, petrochemical industry and the like.

The application discloses a Ti-V-Zr-Cr-Al system ultrahigh-strength near-beta titanium alloy and a preparation method thereof, and belongs to the technical field of titanium alloy materials. The ultrahigh-strength near-beta titanium alloy contains 5.0-5.5% of Al, 11.0-11.5% of V, 2.5-3.0% of Cr, 4.5-5.0% of Zr, and the balance of Ti and inevitable impurity elements according to mass percentage. In the preparation process, firstly, the alloy ingot is subjected to open forging, and then is subjected to upsetting and drawing forging after being cooled to a phase transition point, so that a certain amount of primary alpha phase is formed in the alloy and is uniformly distributed in beta grains, thereby obtaining a titanium alloy forging blank; and then, the titanium alloy forging blank is sequentially subjected to solid solution treatment and aging treatment, thereby obtaining a near-beta ultrahigh-strength titanium alloy with a duplex structure. The titanium alloy has a tensile strength of more than 1800 MPa, a yield strength of 1780 MPa, a fracture elongation of more than 3.2%, and a uniform elongation of more than 2.8%. In particular, the tensile strength reaches 1800 MPa, and the titanium alloy can meet the requirements of the fields of aerospace, energy industry and the like, and has high use value and popularization value.

The application discloses a method for electron beam fuse additive manufacturing of beta titanium alloy components, and belongs to the technical field of additive manufacturing. The application aims to solve the problems of long preparation period, low efficiency, low utilization rate, serious oxidation, significant beta spot and poor strength and toughness of the prior art. The method comprises the following steps: pretreating the printing wire and the substrate; establishing a three-dimensional entity model based on the target beta titanium alloy component, performing slice processing on the three-dimensional entity model to generate multi-layer two-dimensional slice data, and then importing the slice data into an electron beam fuse additive manufacturing equipment, and setting a scanning path, preheating parameters and printing process parameters; starting the equipment and performing vacuumization, printing the beta titanium alloy according to the set printing parameters and procedures, completing all layers, and obtaining the beta titanium alloy component. The beta titanium alloy component prepared by the application has high density, and provides a reliable technical approach for the preparation of high-performance beta titanium alloy components in the fields of aviation and aerospace.

The application discloses a kind of preparation methods of laser forming high-strength titanium alloy based on mixed alloy powder, to solve the problem such as high dependence of high-strength titanium alloy manufacturing on custom powder, poor strength and plasticity matching.The application determines metastable beta titanium alloy and duplex titanium alloy powder ratio based on multidimensional theory; by laser forming, the volume energy density is controlled to be 50-90J / mm 3 In-situ alloying is realized; by two-stage heat treatment, solid solution at 780-900 DEG C and aging at 400-600 DEG C, the heterogeneous structure of large-size primary alpha phase cluster and fine secondary alpha phase interweaving is constructed.The application significantly reduces the preparation cost, and realizes the high coordination of strength and plasticity.

This disclosure provides a method for controlling the multi-level α microstructure of metastable β titanium alloys, including the following steps: Step 1: Metastable β titanium alloy at its β phase transformation point T β Solution treatment within ±50℃; Step 2: Perform multi-pass rolling deformation on the billet obtained in Step 1, with a single-pass deformation amount of 10-30%, and hold at the rolling temperature for 1-10 minutes after every 1-2 passes until the total alloy reduction reaches 70%-95%, then cool to room temperature; Step 3: The billet obtained in Step 2 is subjected to T β -40℃~T β Anneal for 2–120 minutes within the temperature range, then cool to room temperature; or first anneal at T β -80℃~T β Annealing at -40℃ for 20–120 min, then at T β -40℃~T β Annealing for 2–120 minutes within the temperature range, then cooling to room temperature; Step 4: The billet obtained in Step 3 is annealed at T... β -350℃~T β Multi-level α-structures were obtained after aging for 4–12 hours within a temperature range of -210℃. This disclosure enables coupling of primary α-structures. p Secondary α phases of different sizes and spacings s This phase allows metastable β-titanium alloys to possess high strength while retaining a certain degree of plasticity.

The application provides a corrosion-resistant titanium alloy β Titanium alloy and surface modification method thereof, belong to alloy modification technical field.The application includes in β A layer of nano Zn particles is laid on the surface of titanium alloy base material, a gradient structure bottom layer containing Zn is constructed by adopting a friction stir processing technology, the treated base material is handled by compression plasma flow, and a dense smooth surface layer combined with the gradient structure bottom layer containing Zn is constructed.The application constructs a gradient structure bottom layer containing Zn by adopting a friction stir processing technology, handles by compression plasma flow, constructs a dense smooth surface layer combined with the gradient structure bottom layer containing Zn, and is characterized by the following advantages: β The titanium alloy surface forms a composite modified layer with longitudinal gradient structure and low roughness surface layer.The corrosion resistance of the titanium alloy in a simulated physiological environment is significantly improved β The titanium alloy in a simulated physiological environment is significantly improved, and the process is physical modification without harmful reagents, and is suitable for the mechanical matching and biocompatibility requirements of bone implants.

The application relates to the technical field of titanium alloys, in particular to a Ti-Al-V-Mo-Cr-Zr-Nb metastable beta titanium alloy and a preparation method thereof. The Ti-Al-V-Mo-Cr-Zr-Nb metastable beta titanium alloy comprises 3.8-4.6% of aluminum in terms of weight percentage, 5.7-6.5% of vanadium in terms of weight percentage, 4.2-5.2% of molybdenum in terms of weight percentage, 3.0-3.7% of chromium in terms of weight percentage, 1.0-2.2% of zirconium in terms of weight percentage, <=1.0% of niobium in terms of weight percentage, <=0.05% of carbon in terms of weight percentage, <=0.05% of nitrogen in terms of weight percentage, <=0.015% of hydrogen in terms of weight percentage, <=0.15% of oxygen in terms of weight percentage, and the balance is titanium and impurity elements. The purpose of the Ti-Al-V-Mo-Cr-Zr-Nb metastable beta titanium alloy and the preparation method thereof is to solve the problem that the comprehensive performance such as strength, plasticity and toughness of the current super-high-strength titanium alloy is difficult to realize good matching.

This invention relates to the field of metal material testing technology, and particularly to a method for rapidly detecting the original β-grain size of near-β titanium alloys. The method includes the following steps: S1. A low-magnification sheet of a titanium alloy bar or forging is sequentially heated, held at a certain temperature, and cooled to obtain a sample to be tested; S2. The sample to be tested is polished, the surface is polished twice with a mixed acid, rinsed with anhydrous ethanol, and dried to obtain a treated sample; S3. The β-phase grain size on the surface of the treated sample is observed. The heat treatment method used in this invention can ensure that the original β-phase morphology does not change during heat treatment. After surface etching, it allows for direct observation and statistical analysis of the original β-grain size of near-β titanium alloys, which is more convenient for the formulation and optimization of actual titanium alloy production processes.

The application discloses a kind of high-strength plastic β titanium alloy strip and whole-process preparation method, the β titanium alloy strip is composed of the following mass percentage components: Cr 7.7%~8.3%, Mo 4.9%~5.5%, V 4.9%~5.5%, Al 2.7%~3.3%, Fe≤0.20%, C≤0.03%, N≤0.02%, H≤0.010%, O≤0.10%, and the rest is Ti;The preparation method comprises: one, forging;Two, hot rolling;Three, cold rolling;Four, heat treatment.The β titanium alloy strip and whole-process preparation method of the application are overall planning from component design to final heat treatment whole-process procedure, improve production efficiency, shorten preparation time, and the β titanium alloy strip solid solution state microstructure is equiaxed β fine grain structure, strength-plasticity matching is high, horizontal longitudinal organization performance is uniform, with excellent comprehensive mechanical properties, applicable to metal processing field.

This invention provides a method for regulating the microstructure and strength-plasticity matching of metastable β-titanium alloys based on the synergistic mechanism of precipitate growth and dissolution. Metastable β-titanium alloys with a basketweave microstructure are heat-treated using a temperature-controlled sample delivery method, held at a two-phase temperature, and then air-cooled. This invention, through research on the regulation of the size characteristics, phase structure, and phase density of the basketweave α phase at grain boundaries and within grains, simplifies the process while achieving synergistic optimization of strength and plasticity. This addresses a pressing technical bottleneck in the current field of metastable β-titanium alloys, achieving an excellent balance between strength and plasticity in the basketweave microstructure of metastable β-titanium alloys by optimizing heat treatment process parameters.

This invention discloses a method for preparing TB15 metastable β titanium alloy, belonging to the field of titanium alloy heat treatment technology. The method involves performing a two-phase region solution heat treatment on TB15 titanium alloy to obtain a solution-treated titanium alloy containing primary equiaxed αp phases. After holding at this temperature, no cooling treatment is performed. The solution-treated titanium alloy is then directly subjected to aging treatment without cooling at a temperature of 550℃ to 570℃ for 4 to 6 hours, allowing the acicular secondary αs phase to disperse and precipitate before cooling to room temperature. This invention eliminates the traditional water-cooling process after solution treatment, utilizing a transfer heat treatment path of direct heated aging after solution treatment. This avoids the formation of Widmanstätten structure at grain boundaries, effectively improving plasticity and fracture toughness while maintaining high alloy strength. It is suitable for the preparation of titanium alloy structural parts in aerospace, automotive, and other industrial fields.

The present application relates to the field of wear-resistant and corrosion-resistant high-speed rotating screen, in particular to a wear-resistant and corrosion-resistant high-strength titanium alloy slit screen and a preparation method thereof. First, high-strength beta titanium alloy plate material with excellent cold workability and welding performance is selected as raw material, and the screen meeting the size requirements is prepared through laser cutting, cold roll forming and laser welding, and then aging treatment is carried out to meet the performance requirements. Then, the rough inner wall of the laser cutting gap is treated by electrolytic polishing process, so that the roughness is within 0.8 μm. Subsequently, the plate material with slits is rolled into the designed screen shape by using a plate rolling machine, and the both sides are welded by laser, thereby completing the manufacture of the screen shape. Finally, the milling machine is used to process the outside of the screen to have a gradient step profile, so as to reduce the filtrate passing path. The slit screen prepared by the method has high structural strength and rigidity, small running noise, excellent corrosion resistance and wear resistance, and can meet the solid-liquid screening requirements in harsh environment.

An alpha-beta titanium alloy comprising (by weight): 5.0-8.0 % aluminium, 1.0-5.5 % vanadium, 0.75-2.5 5 molybdenum, optionally 0.2-1.0 % iron, 0.1-0.2 % silicon and 0.25 % or less oxygen, with the ba

The application provides a heat treatment method for improving the product of strength and plasticity of a solid solution aging metastable beta titanium alloy to more than 17GPa·%, which comprises the following steps: firstly, solid solution treatment of the metastable beta titanium alloy material at 25-35 DEG C below the beta transformation point; then, high temperature short time heat preservation treatment of the metastable beta titanium alloy material at 55-115 DEG C above the beta transformation point; finally, aging treatment of the metastable beta titanium alloy material at 535-600 DEG C. The microstructure of the metastable beta titanium alloy is regulated by the triple heat treatment, and a multi-scale microstructure composed of a beta matrix with an average grain size of 2.10-2.42 mu m, ellipsoidal primary alpha phase with a volume fraction of not more than 7.94%, an average long axis size of not more than 0.58 mu m and an average short axis size of not more than 0.38 mu m, and coarse and fine combined lamellar secondary alpha phase with a volume fraction of 32.96-51.86% is obtained, so that the product of strength and plasticity of the solid solution aging metastable beta titanium alloy is significantly improved to more than 17GPa·%, and the product of strength and plasticity can be improved to more than 24GPa·% under the optimal heat treatment condition.

The invention provides an antibacterial, corrosion-resistant, high-strength and high-plasticity near-beta titanium alloy, a preparation method and application thereof and an oil gas pipe column, and the antibacterial, corrosion-resistant, high-strength and high-plasticity near-beta titanium alloy comprises, by weight, 4.0%-4.5% of Mo, 4.0%-4.7% of V, 4.4%-5.2% of Al, 0.95%-1.9% of Fe and the balance Fe and inevitable impurities, and the total weight of the antibacterial, corrosion-resistant, high-strength and high-plasticity near-beta titanium alloy is 100%. The alloy comprises, by weight, 0.5%-1.5% of Cr, 0.5%-0.8% of Cu and the balance Ti and inevitable impurity elements. The antibacterial, corrosion-resistant, high-strength and high-plasticity near-beta titanium alloy provided by the invention has the characteristics of high strength, high plasticity and excellent antibacterial and corrosion-resistant properties, and has the potential to become a new generation of high-strength, low-density, antibacterial and corrosion-resistant oil gas pipe column material.

The invention belongs to the technical field of titanium alloy materials, and relates to a thermomechanical treatment method for improving the yield strength of a stress-induced martensite transformation induced plasticity metastable beta titanium alloy to 750MPa or above. The method comprises the following steps that firstly, a metastable beta titanium alloy material is subjected to forging drawing deformation at the temperature 50-80 DEG C lower than the beta transition point, and the total deformation is 70%-85%; then the metastable beta titanium alloy material is subjected to high-temperature short-time heat preservation treatment at the temperature 20-100 DEG C higher than the beta transition point; by means of the thermal mechanical treatment method, a full-beta structure with the average grain size ranging from 30 micrometers to 80 micrometers is obtained in the metastable beta titanium alloy, and a beta-poor stable element microcell with the volume fraction ranging from 65% to 85% and elements not fully diffused is constructed in a beta matrix. Synergistic activation of stress-induced alpha ''martensite transformation and stress-induced omega phase transformation is achieved, the yield strength of the stress-induced alpha'' martensite transformation induced plastic metastable beta titanium alloy is remarkably improved to 750 MPa or above, and meanwhile the uniform elongation percentage of 25% or above is kept all the time.

The application discloses a multi-component high-strength low-elastic modulus dual-phase metastable beta titanium alloy and a preparation method thereof. The titanium alloy takes titanium as a main element, and comprises five beta phase stabilizing elements of vanadium, molybdenum, niobium, chromium and iron, an alpha phase stabilizing element of aluminum and a neutral element of zirconium. The Mo equivalent and electron concentration design method is adopted, so that the Mo equivalent is 7.9, and the e / a electron concentration is 4.07, so that the martensite phase change is more easily induced at room temperature, the elastic modulus of the alloy is reduced, and plasticity is provided. Meanwhile, the deformation twinning is also induced, the work hardening capacity is improved, the increased martensite phase interface and twinning interface hinder the movement of dislocations, and thus the alloy strength is improved. The dual-phase metastable beta titanium alloy quenched after dual-phase zone solid solution treatment has a tensile strength of more than 1 GPa, a yield strength of more than 770 MPa, even reaching 850 MPa, and a plastic elongation of more than 11%, and at the same time, the elastic modulus is lower than 55 GPa.

The α+β titanium alloy ingot for hot working has the following chemical composition: 2.5 to 8.0% of Al, 0.5 to 3.0% of Fe, and O in an amount satisfying 0.02% ≤ [O] ≤ ([Al] - [Fe] - 0.5×[Mo] - 0.5×[Nb] + 1.0) / 100 ([X] represents the content of element X when the unit is mass%), the balance being Ti and impurities, the ratio L / S of the circumference L (mm) of the cross section perpendicular to the length direction, i.e., the cross section, to the area S (mm 2 ) of the cross section is 0.010 or more, the average grain diameter D of the casting structure at a position 10 mm from the surface toward the center axis of the α+β titanium alloy ingot in the length direction satisfies D ≤ 10 mm and D ≤ L / 100 in a portion of 20 to 80% of the total length from one of the two end surfaces in the length direction of the α+β titanium alloy ingot toward the other end surface and relative to the length direction, and the thickness of the α+β titanium alloy ingot is 80 mm or more.

The invention discloses a Ti-Mo series high-plasticity metastable beta titanium alloy plate and a preparation method thereof.The method comprises the steps that firstly, a Ti-12Mo alloy ingot obtained through three-time vacuum arc melting is subjected to four-heating-number hot forging, and a forged plate blank is obtained; secondly, the forged plate blank is subjected to three-heating-number hot rolling, and a hot-rolled plate is obtained; thirdly, the hot-rolled plate is subjected to annealing treatment; and fourthly, the hot-rolled plate obtained after annealing treatment is subjected to sand blasting, acid pickling and leveling, and the high-plasticity metastable beta titanium alloy plate is obtained. By adjusting the temperature and the deformation amount in the forging process and optimizing the hot rolling temperature and the plate solution treatment system, omega brittle phase precipitation is effectively restrained, a metastable beta phase is locked, the plastic phase transformation potential is introduced for subsequent deformation, the high-plasticity titanium alloy plate uniform in thickness and good in surface quality is obtained, and the titanium alloy plate can be stamped, deeply drawn and bent into a complex shape; and the application requirements in different fields such as aerospace and electronic appliances are met.

The invention discloses application of a metastable beta titanium alloy in wide-temperature-range solid-state refrigeration, and belongs to the technical field of solid-state refrigeration. The metastable beta titanium alloy serves as a solid-state refrigeration working medium, transformation from a body-centered cubic structure to an orthogonal structure occurs under stress driving, and a heat effect is generated to achieve refrigeration. The alloy comprises the following components in percentage by mass: 20-36% of Nb, 2-5% of Zr, 6-10% of Sn and the balance of Ti and inevitable impurities. The material can realize adiabatic temperature change of 4.2 K at most in a temperature range of 1.59-298 K, and the fatigue life at room temperature exceeds 1 million weeks, and also exceeds 0.5 million weeks in a low-temperature environment, so that the material is obviously superior to other elastic and thermal material systems. Meanwhile, the alloy shows excellent electrochemical stability, and the pitting potential in a 3.5 wt% NaCl solution exceeds 10 V (relative to an Ag / AgCl electrode).

The application provides a metastable beta titanium alloy with a yield ratio lower than 0.6 and a preparation method thereof. The titanium alloy comprises the following components and mass percentages: 78-82% of Ti, 18-20% of V, 0.5-1% of Fe, 0.03-0.08% of O, and the balance of inevitable impurities. The preparation method comprises the following steps: vacuum arc melting, vacuum homogenization annealing, hot rolling, cold rolling, vacuum solid solution heat treatment and the like. The titanium alloy provided by the application can generate stress-induced omega phase lath attached with a thin layer of non-identical variant omega phase on the boundary and / or {332}<113> deformation twin attached with a thin layer of omega phase on the twin boundary during deformation. The formation of the omega phase lath or twin can greatly improve the work hardening capacity and plasticity of the corresponding alloy, thereby reducing the yield ratio to 0.6 or less, and under the condition of the optimal component ratio, the yield ratio can be reduced to 0.51. The application solves the problem of high yield ratio of the existing metastable beta titanium alloy, and the titanium alloy is suitable for manufacturing a new type of cold-formed high-strength component for an aircraft.

The application provides a metastable beta titanium alloy combining gap oxygen solid solution strengthening and stress-induced omega phase transformation induced plasticity and a preparation method thereof. The titanium alloy comprises 18-20% of V, 0.15-0.4% of O and the balance of Ti and trace amounts of impurity elements in terms of mass percentage. The preparation method comprises the steps of vacuum arc melting, vacuum homogenization annealing, hot rolling, cold rolling and vacuum solid solution heat treatment. The titanium alloy provided by the application improves the solid solution strengthening effect by introducing the gap oxygen element, and on the other hand, by regulating the deformation mechanism, the stress-induced omega phase transformation is used to excite the phase transformation induced plasticity effect, so that the high yield strength and high work hardening capacity are obtained. The yield strength of the titanium alloy provided by the application is more than 500 MPa, the tensile strength is more than 784 MPa, and meanwhile, the titanium alloy still has excellent plasticity and work hardening capacity, and can be potentially applied to new aero-engine gearboxes, landing gears and hydraulic system components.

The application discloses a preparation method of a metastable beta titanium alloy three-state structure, which comprises the following steps: firstly, using high-energy pulse current rapid heating technology to heat the titanium alloy as a whole; secondly, using medium-temperature short-time heat preservation treatment to obtain a small amount of micron-sized alpha lath; finally, continuing to use low-temperature aging treatment to promote the precipitation of nanometer-sized alpha lamella, so that fine nanometer alpha lamella is dispersedly distributed, and finally, a new three-state structure containing equiaxed alpha phase, micron-sized lath alpha phase and uniform nanometer lamella alpha phase is obtained in the titanium alloy; by adjusting the process parameters of pulse electric heating and pseudo-amplitude decomposition mechanism, the three-state structure can be quickly and efficiently prepared in the metastable beta titanium alloy; compared with the traditional titanium alloy structure, the three-state structure is beneficial to improving the comprehensive mechanical properties of the alloy; the preparation method is environment-friendly and economical, simple to operate, improves the efficiency and reduces the energy consumption, and has a wide application prospect.