High-strength Ti-Cr-V-Al-Zr series titanium alloy and preparation method

Abstract

The invention discloses a high-strength Ti-Cr-V-Al-Zr series titanium alloy and a preparation method thereof, and belongs to the technical field of metal materials. The titanium alloy comprises, by mass, 5.0%-6.0% of Cr, 7.0%-9.0% of V, 5.0%-7.0% of Al, 7.0%-10.5% of Zr, smaller than or equal to 0.15% of O and the balance Ti and impurities. The preparation method comprises the steps that raw materials are mixed and then subjected to cold crucible magnetic levitation smelting under high-purity argon, the induction current ranges from 450 A to 500 A, and the frequency ranges from 20 kHz to 25 kHz; then cogging forging, beta-phase region forging and two-phase region multi-directional forging are conducted in sequence; and finally, carrying out solid solution at 760 DEG C for 60 minutes, carrying out water quenching, aging at 480-520 DEG C for 120 minutes, and carrying out air cooling. Through reasonable composition proportion, on the premise that expensive refractory elements such as Mo and Nb are removed, a multi-scale alpha / beta composite structure is formed through the synergistic effect of Zr and Al, and the structure uniformity is controlled in cooperation with a specific smelting and forging process, so that the yield strength of the alloy reaches 1550-1737 MPa, the tensile strength is 1613-1778 MPa, the ductility is 5.1-9.4%, and the alloy has excellent comprehensive mechanical properties and cost advantages and is suitable for industrial production. The method is suitable for high-performance structural members in the fields of aerospace and the like.

Description

Technical Field

[0001] This invention relates to the field of metallic materials technology, specifically to a high-strength Ti-Cr-V-Al-Zr titanium alloy and its preparation method. Background Technology

[0002] Titanium alloys possess a range of characteristics, including high specific strength, high damage tolerance, and excellent fatigue resistance, making them a highly valued structural material in the field of new materials. Among them, metastable β-type titanium alloys can achieve excellent properties through heat treatment. The aerospace industry has extremely high requirements for structural components, demanding not only high strength and toughness but also long-term service under high and low temperature conditions. Titanium alloys are best suited to these service conditions due to their properties.

[0003] Metastable β-type titanium alloys can have their strength significantly improved by applying deformation and appropriate heat treatment to adjust their microstructure, making them one of the most widely used titanium alloys in research and engineering applications. For example, Ti1023 and Ti5553, after solution aging, can achieve a tensile strength of 1200 MPa, while titanium alloys such as TB15 and TB17 can achieve tensile strengths exceeding 1300 MPa after solution aging. However, with the development of aerospace technology, the existing properties of titanium alloys can no longer meet the modern aerospace industry's demands for "higher, farther, and stronger" capabilities.

[0004] Therefore, it is necessary to develop titanium alloys with better mechanical properties to meet the performance requirements of titanium alloy materials in the aerospace field. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a high-strength Ti-Cr-V-Al-Zr titanium alloy and its preparation method. This titanium alloy contains no refractory elements, is less prone to compositional segregation, and possesses excellent comprehensive mechanical properties while maintaining the advantage of low cost.

[0006] This invention is achieved through the following technical solution: A high-strength Ti-Cr-V-Al-Zr titanium alloy, comprising, by mass percentage: 5.0~6.0% Cr, 7.0~9.0% V, 5.0~7.0% Al, 7.0~10.5% Zr, O≦0.15%, with the balance being Ti and unavoidable impurities.

[0007] Preferably, the microstructure of the titanium alloy is a two-phase structure comprising a β-phase matrix and precipitated α-phase; the precipitated α-phase includes a primary α-phase and a secondary α-phase, wherein the primary α-phase is equiaxed or spherical with a size of 0.6~1.3μm, and the secondary α-phase is lamellar or needle-like with a thickness of 50~120nm.

[0008] Preferably, the titanium alloy has a yield strength Rp of 1550MPa to 1737MPa, a tensile strength Rm of 1613MPa to 1778MPa, and a total elongation at break A of 5.1% to 9.4%.

[0009] A method for preparing a high-strength Ti-Cr-V-Al-Zr titanium alloy includes the following steps: Step 1: After mixing the raw materials evenly according to the stated mass percentage, perform multiple melting processes in a high-purity argon atmosphere to obtain a casting with uniform composition. Step 2: The ingot is subjected to blank forging, β phase region forging and two-phase region multi-directional forging in sequence; Step 3: The forged ingot is subjected to solution treatment and aging treatment to obtain the high-strength Ti-Cr-V-Al-Zr titanium alloy; The aging treatment is performed at a temperature of 480-520℃, and the holding time is 120 minutes, followed by air cooling to room temperature.

[0010] Preferably, in step 1, the melting is carried out using cold crucible magnetic levitation melting, with an induced current of 450-500A and a current frequency of 20-25 kHz, and the melting is maintained for 15-20 minutes after the alloy is completely melted.

[0011] Preferably, in step 2, the temperature of the billet forging is 1000℃-1200℃, the holding time is 60-120min, and the deformation is ≥60%.

[0012] Preferably, in step 2, the forging temperature of the β phase region is 850℃-1000℃, the holding time is 60-120min, and the deformation is ≥50%.

[0013] Preferably, in step 2, the temperature of the two-phase region multi-directional forging is 740-780℃, the holding time is 120min, and the deformation amount in each direction is ≥40%.

[0014] Preferably, in step 3, the solution treatment involves solution treatment at 760°C for 60 minutes followed by water quenching to room temperature.

[0015] An aerospace structural component is made of the aforementioned high-strength Ti-Cr-V-Al-Zr titanium alloy; Alternatively, the manufacturing method of the aerospace structural component may include using the preparation method described above to prepare the high-strength Ti-Cr-V-Al-Zr titanium alloy, and then processing it into the required aerospace structural component.

[0016] Compared with the prior art, the present invention has the following beneficial technical effects: This application provides a high-strength Ti-Cr-V-Al-Zr titanium alloy. Cr and V, as strong β-stabilizing elements, are designed to obtain a fully supersaturated metastable β-phase matrix after solution treatment, providing the necessary prerequisite for the large-scale, dispersed precipitation of the secondary α-phase during aging. The introduction of Al not only acts as an α-phase stabilizer but also directly enhances the matrix strength through the solution effect. The addition of Zr plays a crucial role in microalloying. Zr and Al have a low enthalpy of mixing, making them prone to segregation at the α / β phase boundary. This segregation behavior not only significantly refines the size of the primary α-phase but also guides the uniform precipitation of the secondary α-phase at the nanoscale during aging, forming a dual-scale α-phase distribution. This multi-scale composite structure, through the coupling mechanism of phase boundary strengthening and precipitation strengthening, constructs a dense dislocation movement barrier in the β-phase matrix, significantly improving the material's resistance to plastic deformation. This titanium alloy composition completely eliminates expensive refractory elements such as Mo and Nb, as well as the easily segregated element Fe. Through conventional heat treatment, it can achieve a yield strength of over 1550 MPa while maintaining an elongation of over 5.3%, achieving a good match between high strength and moderate plasticity. This breaks through the problem of traditional high-strength β-titanium alloys relying on expensive elements or sacrificing plasticity.

[0017] This application provides a method for preparing a high-strength Ti-Cr-V-Al-Zr titanium alloy, employing a three-stage forging process: billet forging, β-phase forging, and two-phase multi-directional forging. Billet forging is performed in the β single-phase region at 1000-1200℃, breaking down the original coarse cast grains through large deformation to establish a uniform deformed matrix for subsequent processing. β-phase forging is carried out at 850-1000℃, further refining the grain size and eliminating any processing banding that may remain from the billet forging while retaining the β phase. The forging is performed in the (α+β) two-phase region at 740-780℃. In this temperature range, the primary α phase has begun to precipitate but has not yet coarsened. Applying multi-directional deformation at this temperature allows the primary α phase to be sheared, fragmented, and redistributed in multiple directions, forming fine equiaxed or lath-like structures. This three-dimensional α-phase network provides numerous non-uniform nucleation sites for the nucleation of secondary α phases during subsequent aging. The final solution-aging heat treatment is a functional activation of the forged structure: the 760℃ solution treatment allows the alloying elements to reach the optimal solubility in the β matrix, and the water quenching freezes them into a supersaturated state; the subsequent precise aging at 480-520℃ utilizes the thermodynamic instability of the β phase to promote the precipitation of nanoscale secondary α phases from the matrix at extremely high density. These secondary α phases complement the primary α phases formed by forging, forming a multi-scale, multi-morphological strengthening phase distribution network. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a microstructure diagram of the high-strength metastable β-titanium alloy of Example 1 of the present invention; Figure 2 This is a microstructure diagram of the high-strength metastable β-titanium alloy of Example 2 of the present invention; Figure 3 This is a microstructure diagram of the high-strength metastable β-titanium alloy in Example 3 of the present invention; Figure 4 The table shows the room temperature tensile properties of the Ti-Cr-V-Al-Zr titanium alloy as an example of this invention after solution treatment and aging. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0021] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0022] A high-strength Ti-Cr-V-Al-Zr titanium alloy, comprising, by mass percentage: 5.0~6.0% Cr, 7.0~9.0% V, 5.0~7.0% Al, 7.0~10.5% Zr, O≦0.15%, with the balance being Ti and other unavoidable impurities. After solution cooling and aging in the two-phase region, the alloy exhibits a typical equiaxed α phase in the β matrix, with a size between 0.6 and 1.3 μm. The thickness of the precipitated lamellar secondary α phase is between 50 and 120 nm. In this composite structure, the fine and dispersed equiaxed α phase provides deformability, while the nanoscale secondary α phase provides strength, giving the alloy high strength and high toughness.

[0023] The titanium alloy has a yield strength Rp of 1550 MPa to 1737 MPa, a tensile strength Rm of 1613 MPa to 1778 MPa, and a total elongation at break A of 5.1% to 9.4%.

[0024] This Ti-Cr-V-Al-Zr titanium alloy removes refractory elements Mo and Nb, as well as expensive element Mo and Fe, which easily causes segregation and β-spots. Al and Zr are added, taking advantage of their low enthalpy of mixing and easy agglomeration, which facilitates the composite strengthening of the α phase and thus improves the overall strength of the alloy. Cr and V, as β-stabilizing elements, have a strong solid solution strengthening effect, further improving the mechanical properties of the alloy. Sufficient shear resistance is generated at the α / β interface, reducing the mean free slip path of dislocations in the alloy, thus giving the alloy excellent comprehensive mechanical properties.

[0025] Correspondingly, this application also provides a method for preparing the above-mentioned high-strength Ti-Cr-V-Al-Zr titanium alloy, including the following steps: Step 1: Mix the raw materials evenly according to the above mass percentage, put them into the furnace and melt them multiple times in a high-purity argon atmosphere to obtain a uniformly composed ingot. Then, peel off the skin and cut the riser of the ingot to obtain a titanium alloy ingot. During the melting process, high-purity argon gas is introduced, the induced current is 450-500A, and the current frequency is 20-25KHz. After the alloy is completely melted, the process is maintained for 15-20 minutes.

[0026] Step 2: Free forging of titanium alloy ingots. Free forging includes sequentially performing initial forging, β-phase region forging, and two-phase region multi-directional forging on the ingots. The forging temperature is 1000℃-1200℃, the holding time is 60-120min, and the deformation is ≥60%.

[0027] The forging temperature of the β phase region is 850℃-1000℃, the holding time is 60-120min, and the deformation is ≥50%.

[0028] The forging temperature of the two-phase region is 740-780℃, the holding time is 120min, and the deformation in each direction is ≥40%.

[0029] Step 3: Heat treat the forged titanium alloy ingot in the two-phase region to obtain a Ti-Cr-V-Al-Zr titanium alloy.

[0030] The heat treatment involves solution treatment at 760℃ for 60 minutes, followed by water quenching to room temperature, and then aging treatment at 480-520℃ for 120 minutes, and finally air cooling to room temperature.

[0031] This high-strength Ti-Cr-V-Al-Zr titanium alloy employs multiple smelting processes, resulting in a simple and short-process fabrication method. Through rational component proportioning and microstructure design, combined with mature titanium alloying theory, a multi-scale primary α-phase and nano-secondary α-phase composite microstructure is formed within the β-phase matrix. Excellent synergy between strength and plasticity can be achieved through simple heat treatment. This alloy significantly reduces the overall manufacturing cost of high-performance titanium alloys while saving raw materials and processing costs, meeting the demands of various industrial applications for advanced titanium alloy structural components.

[0032] Example 1 A high-strength Ti-Cr-V-Al-Zr titanium alloy is composed of the following components by mass percentage: Cr-5.22%, V-7.76%, Al-5.83%, Zr-7.99%, O-0.099%, with the balance being Ti and other unavoidable impurities.

[0033] The preparation method of this high-strength Ti-Cr-V-Al-Zr titanium alloy includes the following steps: Step 1: Prepare the master alloy using a cold crucible magnetic levitation melting method. Take high-purity titanium, high-purity Cr, high-purity V, high-purity Al, and high-purity Zr, weigh them according to their mass percentages, and weigh them to an accuracy of 0.01g.

[0034] The above raw materials are mixed evenly and then bulked into a cold crucible suspension melting furnace. High-purity argon gas is introduced during the melting process, with an induced current of 480A and a current frequency of 22KHz. After the alloy is completely melted, it is held for 15 minutes. To ensure uniform composition, after the ingot cools, it is inverted and melting is continued. The melting process is repeated no less than 5 times.

[0035] Step 2: Forging the master alloy into a billet. Cut the riser from the master alloy ingot obtained in step 1 and perform forging. The forging temperature is 1150℃, the holding time is 120min, the forging method is three-stage forging and three-stage drawing, and the deformation is 60%.

[0036] Step 3: The master alloy after billet forging is subjected to two β-phase region forgings. The first forging temperature is 1000℃, the holding time is 120min, the forging method is three-stage forging and three-stage drawing, and the deformation is 50%. The second forging temperature is 890℃, the holding time is 120min, the forging method is three-stage forging and three-stage drawing, and the deformation is 50%.

[0037] Step 4: The master alloy after β phase region forging is subjected to two-phase region multi-directional forging. The forging temperature is 780℃, the holding time is 120min, the forging method is multi-directional forging, and the deformation amount in each direction is 40%.

[0038] Step 5: Perform solution treatment and aging on the ingot after multi-directional forging in the two-phase region.

[0039] Ti-Cr-V-Al-Zr titanium alloys were solution-treated at 760℃ for 60 min in the α+β two-phase region, water-cooled to room temperature, aged at 480℃ for 120 min, and air-cooled to room temperature.

[0040] The organizations obtained, such as Figure 1 As shown, after solution cooling and aging in the two-phase region, a typical equiaxed α phase with a size of approximately 0.6–1.2 μm appears in the β matrix, along with a lamellar secondary α phase with a thickness of approximately 50–80 nm. In this composite structure, the fine, dispersed equiaxed α phase provides deformability, while the nanoscale secondary α phase provides strength, giving the alloy high strength and high toughness. The GB / T228.1-2021 standard requires that the measured mechanical properties of the alloy be as follows... Figure 4 As shown in curve 1, the yield strength is Rp=1737MPa, the tensile strength is Rm=1778MPa, and the total elongation at break is A=5.1%.

[0041] Example 2 A high-strength Ti-Cr-V-Al-Zr titanium alloy is composed of the following components by mass percentage: Cr-5.22%, V-7.76%, Al-5.83%, Zr-7.99%, O-0.099%, with the balance being Ti and other unavoidable impurities.

[0042] The preparation method of high-strength Ti-Cr-V-Al-Zr titanium alloy in this embodiment specifically includes the following steps: Step 1: Prepare the master alloy using a cold crucible magnetic levitation melting method. Take high-purity titanium, high-purity Cr, high-purity V, high-purity Al, and high-purity Zr, weigh them according to their mass percentages, and weigh them to an accuracy of 0.01g.

[0043] The above raw materials are mixed evenly and then bulked into a cold crucible suspension melting furnace. High-purity argon gas is introduced during the melting process, with an induced current of 480A and a current frequency of 22KHz. After the alloy is completely melted, it is held for 15 minutes. To ensure uniform composition, after the ingot cools, it is inverted and melting is continued. The melting process is repeated no less than 5 times.

[0044] Step 2: Forging the master alloy into a billet. Cut the riser from the master alloy ingot obtained in step 1 and perform forging. The forging temperature is 1150℃, the holding time is 120min, the forging method is three-stage forging and three-stage drawing, and the deformation is 60%.

[0045] Step 3: The master alloy after billet forging is subjected to two β-phase region forgings. The first forging temperature is 1000℃, the holding time is 120min, the forging method is three-stage forging and three-stage drawing, and the deformation is 50%. The second forging temperature is 890℃, the holding time is 120min, the forging method is three-stage forging and three-stage drawing, and the deformation is 50%.

[0046] Step 4: The master alloy after β phase region forging is subjected to two-phase region multi-directional forging. The forging temperature is 780℃, the holding time is 120min, the forging method is multi-directional forging, and the deformation amount in each direction is 40%.

[0047] Step 5: Perform solution treatment and aging on the ingot after multi-directional forging in the two-phase region.

[0048] Ti-Cr-V-Al-Zr titanium alloys were solution-treated at 760℃ for 60 min in the α+β two-phase region, water-cooled to room temperature, aged at 500℃ for 120 min, and air-cooled to room temperature.

[0049] The organizations obtained, such as Figure 2 As shown, after solution cooling and aging in the two-phase region, a typical equiaxed α phase with a size of approximately 0.6–1.2 μm appears in the β matrix, along with a lamellar secondary α phase with a thickness of approximately 60–100 nm. In this composite structure, the fine, dispersed equiaxed α phase provides deformability, while the nanoscale secondary α phase provides strength, giving the alloy high strength and high toughness. The mechanical properties of the alloy were measured according to the requirements of GB / T228.1-2021 standard as follows: Figure 4 As shown in curve 2, the yield strength is Rp=1650MPa, the tensile strength is Rm=1703MPa, and the total elongation at break is A=8.1%.

[0050] Example 3 A method for preparing a high-strength Ti-Cr-V-Al-Zr titanium alloy, comprising the following components by mass percentage: Cr-5.22%, V-7.76%, Al-5.83%, Zr-7.99%, O-0.099%, with the balance being Ti and other unavoidable impurities.

[0051] The preparation method of high-strength Ti-Cr-V-Al-Zr titanium alloy in this embodiment specifically includes the following steps: Step 1: Prepare the master alloy using a cold crucible magnetic levitation melting method. Take high-purity titanium, high-purity Cr, high-purity V, high-purity Al, and high-purity Zr, weigh them according to their mass percentages, and weigh them to an accuracy of 0.01g.

[0052] The above raw materials are mixed evenly and then bulked into a cold crucible suspension melting furnace. High-purity argon gas is introduced during the melting process, with an induced current of 480A and a current frequency of 22KHz. After the alloy is completely melted, it is held for 15 minutes. To ensure uniform composition, after the ingot cools, it is inverted and melting is continued. The melting process is repeated no less than 5 times.

[0053] Step 2: Forging the master alloy into a billet. Cut the riser from the master alloy ingot obtained in step 1 and perform forging. The forging temperature is 1150℃, the holding time is 120min, the forging method is three-stage forging and three-stage drawing, and the deformation is 60%.

[0054] Step 3: The master alloy after billet forging is subjected to two β-phase region forgings. The first forging temperature is 1000℃, the holding time is 120min, the forging method is three-stage forging and three-stage drawing, and the deformation is 50%. The second forging temperature is 890℃, the holding time is 120min, the forging method is three-stage forging and three-stage drawing, and the deformation is 50%.

[0055] Step 4: The master alloy after β phase region forging is subjected to two-phase region multi-directional forging. The forging temperature is 780℃, the holding time is 120min, the forging method is multi-directional forging, and the deformation amount in each direction is 40%.

[0056] Step 5: Perform solution treatment and aging on the ingot after multi-directional forging in the two-phase region.

[0057] Ti-Cr-V-Al-Zr titanium alloys were solution-treated at 760℃ for 60 min in the α+β two-phase region, water-cooled to room temperature, aged at 520℃ for 120 min, and air-cooled to room temperature.

[0058] The organizations obtained, such as Figure 3 As shown, after solution cooling and aging in the two-phase region, a typical equiaxed α phase with a size of approximately 0.6–1.3 μm appears in the β matrix, along with a lamellar secondary α phase with a thickness of approximately 70–120 nm. In this composite structure, the fine, dispersed equiaxed α phase provides deformability, while the nanoscale secondary α phase provides strength, giving the alloy high strength and high toughness. The mechanical properties of the alloy were measured according to the requirements of GB / T228.1-2021 standard as follows: Figure 4 As shown in curve 3, the yield strength is Rp=1550MPa, the tensile strength is Rm=1613MPa, and the total elongation at break is A=9.4%.

[0059] It should be noted that the above embodiments are merely specific implementation examples of the present invention, used to verify the technical effects of the present invention, and are not intended to limit the present invention.

[0060] 1. Regarding the composition: Within the mass percentage range described in this invention (Cr: 5.0~6.0%, V: 7.0~9.0%, Al: 5.0~7.0%, Zr: 7.0~10.5%, O≤0.15%), those skilled in the art can appropriately adjust and combine the content of each element according to actual performance requirements to obtain a metastable β-type titanium alloy with high strength.

[0061] 2. Regarding the aging temperature: The aging treatment temperature can be selected between 480℃ and 520℃. When the aging temperature increases from low to high within this range, the size of the precipitated secondary α phase gradually increases while its quantity density decreases, thereby gradually reducing the yield strength and tensile strength of the alloy, while correspondingly increasing the elongation at break. As shown in Examples 1-3, when the aging temperatures are 480℃, 500℃, and 520℃, the alloy exhibits different performance combinations ranging from high strength and hardness to a better match between strength and plasticity. Therefore, those skilled in the art can select a suitable temperature within the aging temperature range disclosed in this invention according to the specific requirements for the strength and plasticity of the component.

[0062] 3. Regarding other process parameters: The forging temperature, β-phase region forging temperature, two-phase region forging temperature, and their respective holding times and deformation amounts in the forging process can all be adjusted within the range given in this invention. The temperature and time of the solution treatment can also be fine-tuned according to the actual microstructure of the ingot, with the principle of obtaining a uniform supersaturated metastable β-phase matrix.

[0063] In summary, the high-strength Ti-Cr-V-Al-Zr titanium alloy provided by this invention, through reasonable composition design, contains no refractory elements Mo and Nb, and no easily segregating element Fe. After melting, forging, solution treatment, and aging heat treatment, the alloy achieves excellent comprehensive mechanical properties. Because the alloy contains no expensive element Mo, the raw material cost is lower, giving the Ti-Cr-V-Al-Zr titanium alloy a low-cost advantage, which can meet the high-performance requirements of various industrial fields for titanium alloy structural components.

[0064] Correspondingly, this application also provides an aerospace structural component made of the aforementioned high-strength Ti-Cr-V-Al-Zr titanium alloy; Alternatively, the manufacturing method of the aerospace structural component may include using the preparation method described above to prepare the high-strength Ti-Cr-V-Al-Zr titanium alloy, and then processing it into the required aerospace structural component.

[0065] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A high-strength Ti-Cr-V-Al-Zr-based titanium alloy, characterized by comprising, in mass %, By mass percentage, it comprises: 5.0-6.0% of Cr, 7.0-9.0% of V, 5.0-7.0% of Al, 7.0-10.5% of Zr, O<=0.15%, and the balance of Ti and inevitable impurities.

2. The high-strength Ti-Cr-V-Al-Zr-based titanium alloy according to claim 1, characterized in that, The microstructure of the titanium alloy is a duplex structure comprising a beta phase matrix and precipitated alpha phases; the precipitated alpha phases comprise primary alpha phases and secondary alpha phases, wherein the primary alpha phases are equiaxed or spherical, and the size is 0.6-1.3 μm, and the secondary alpha phases are flaky or needle-shaped, and the thickness is 50-120 nm.

3. The high-strength Ti-Cr-V-Al-Zr-based titanium alloy of claim 1, wherein, The yield strength Rp of the titanium alloy is 1550-1737 MPa, the tensile strength Rm is 1613-1778 MPa, and the total elongation at break A is 5.1-9.4%.

4. A method of producing a high-strength Ti-Cr-V-Al-Zr-based titanium alloy according to any one of claims 1 to 3, characterized by, The method comprises the following steps: Step 1, after the raw materials are uniformly mixed according to the mass percentage, multiple melting is carried out under a high-purity argon environment to obtain a uniformly-composed ingot; Step 2, the ingot is sequentially subjected to open-die forging, beta phase zone forging and two-phase zone multi-directional forging; Step 3, the forged ingot is subjected to solid solution treatment and aging treatment to obtain the high-strength Ti-Cr-V-Al-Zr titanium alloy; The temperature of the aging treatment is 480-520℃, and the holding time is 120 min, followed by air cooling to room temperature.

5. The method for preparing the high-strength Ti-Cr-V-Al-Zr titanium alloy according to claim 4, characterized in that, In step 1, the melting adopts cold-crucible magnetic levitation melting, the induction current is 450-500 A, and the current frequency is 20-25 kHz; after the alloy is completely melted, it is continuously maintained for 15-20 min.

6. The method of claim 4, wherein the high-strength Ti-Cr-V-Al-Zr-based titanium alloy is prepared by the steps of: preparing a master alloy by mixing and melting a predetermined amount of Ti, Cr, V, Al, and Zr; and casting the master alloy into a predetermined shape. In step 2, the temperature of the open-die forging is 1000-1200℃, the holding time is 60-120 min, and the deformation amount is >=60%.

7. The method of claim 4, wherein the high-strength Ti-Cr-V-Al-Zr-based titanium alloy is prepared by the steps of: preparing a master alloy by mixing and melting a predetermined amount of Ti, Cr, V, Al, and Zr; and casting the master alloy into a predetermined shape. In step 2, the temperature of the beta phase zone forging is 850-1000℃, the holding time is 60-120 min, and the deformation amount is >=50%.

8. The method of claim 4, wherein the high-strength Ti-Cr-V-Al-Zr-based titanium alloy is prepared by the steps of: preparing a master alloy by mixing and melting a predetermined amount of Ti, Cr, V, Al, and Zr; and casting the master alloy into a predetermined shape. In step 2, the temperature of the two-phase zone multi-directional forging is 740-780℃, the holding time is 120 min, and the deformation amount of each direction is >=40%.

9. The method of claim 4, wherein the high-strength Ti-Cr-V-Al-Zr-based titanium alloy is prepared by the steps of: preparing a master alloy by mixing and melting a predetermined amount of Ti, Cr, V, Al, and Zr; and casting the master alloy into a predetermined shape. In step 3, the solid solution treatment is water quenching to room temperature after being solid-solved at 760℃ for 60 min.

10. An aerospace structure, characterized by, It is made of the high-strength Ti-Cr-V-Al-Zr titanium alloy of claim 1 or 2; Alternatively, the manufacturing method of the aerospace structural part comprises the preparation method of any one of claims 3-10, and the high-strength Ti-Cr-V-Al-Zr titanium alloy is prepared and then processed into the required aerospace structural part.

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