A titanium alloy bar with high strength and high toughness and a preparation method thereof

Abstract

The present invention belongs to the field of titanium alloys, and specifically relates to a titanium alloy bar with high strength and high toughness and a method for preparing the same. The titanium alloy comprises, by mass percentage, 63% to 65% Ti, 22% to 25% Nb, 3% to 5% Zr, 7% to 9% Sn, and 0.05% to 0.2% O. The titanium alloy has a crack initiation toughness of 56.2 to 165.6 kJ / m 2 , crack extension toughness is 67.0~241.7kJ / m 2 , a tensile strength of 650-800 MPa, an elongation of 5%-17%, and an elastic modulus of 50-60 GPa. This invention does not involve the preparation of porous materials, solid solution, or water quenching processes, and does not rely on the phase transformation from the parent phase to the martensite phase to achieve high toughness. Instead, it achieves an alloy material with both high strength and high toughness through a completely different working principle.

Description

Technical Field

[0001] The present invention belongs to the field of titanium alloys, and in particular relates to a titanium alloy bar with high strength and high toughness and a preparation method thereof. Background Art

[0002] Titanium alloys, due to their excellent specific strength, corrosion resistance, and biocompatibility, are widely used in high-tech fields such as aerospace, medical, and automotive. With the development of science and technology, the performance requirements of titanium alloys are constantly increasing. In particular, high-strength and high-toughness titanium alloys have important application prospects in fields such as aerospace and medical implants.

[0003] 1. Titanium alloy materials in existing technology

[0004] (1) α-type titanium alloy: α-type titanium alloy has good toughness and oxidation resistance, but its strength is relatively low and it is difficult to meet the needs of some high-strength applications.

[0005] (2) β-type titanium alloy: β-type titanium alloy is widely used in high-strength applications due to its high strength and good plasticity. However, β-type titanium alloy generally has a low elastic modulus, which limits its application in certain fields requiring high toughness.

[0006] (3) α+β titanium alloy: α+β titanium alloy combines the advantages of both α and β phases and has good overall performance. However, in practical applications, this type of alloy still faces a contradiction between strength and toughness, and it is difficult to achieve an optimal balance between high strength and high toughness.

[0007] 2. Existing preparation process of titanium alloy bars

[0008] The traditional titanium alloy bar preparation process mainly includes smelting, forging and heat treatment. These processes can improve the strength and toughness of the material to a certain extent, but they often face the following problems:

[0009] (1) The balance between strength and toughness is difficult to achieve: Existing titanium alloy materials often sacrifice their toughness while improving their strength, making it difficult to meet the requirements of high strength and high toughness at the same time.

[0010] (2) High cost: The preparation cost of titanium alloy materials is relatively high. The preparation process design, such as solid solution and water quenching, is relatively complex and has high requirements for equipment and technology, which limits its promotion and application in some fields. Summary of the Invention

[0011] The purpose of the present invention is to provide a titanium alloy rod with high strength and high toughness and a preparation method thereof, so as to solve the problem that titanium alloy rods in the prior art cannot meet the requirements of both high strength and high toughness. By optimizing the alloy composition and preparation process, the comprehensive performance of the titanium alloy is significantly improved to meet the application needs of high-end fields such as aerospace and medical care.

[0012] The technical solution of the present invention is:

[0013] A titanium alloy rod with high strength and high toughness, the titanium alloy rod contains a metastable bcc structure β phase, and the composition of the titanium alloy is as follows by mass percentage: Ti 63% to 65%, Nb 22% to 25%, Zr 3% to 5%, Sn 7% to 9%, and O 0.05% to 0.2%. The titanium alloy has a crack initiation toughness of 56.2 to 165.6 kJ / m 2 , crack extension toughness is 67.0~241.7kJ / m 2 , tensile strength 650~800MPa, elongation 5%~17%, elastic modulus 50~60GPa.

[0014] The titanium alloy bar with high strength and high toughness has the following preferred composition contents: Ti 63.87%, Nb 24.0%, Zr 4.0%, Sn 8.0%, and O 0.13%.

[0015] The method for preparing the titanium alloy bar with high strength and high toughness is carried out in the following steps:

[0016] (1) Adjusting the composition ratio so that the mass percentage of the element composition of the titanium alloy satisfies the following: Ti 63% to 65%, Nb 22% to 25%, Zr 3% to 5%, Sn 7% to 9%, and O 0.05% to 0.2%;

[0017] (2) Pressing the alloy electrode and vacuum melting it for 2 to 6 times;

[0018] (3) Forging and blanking - cooling, controlling the forging temperature to 700-1250°C, the deformation to 10-50%, the cooling rate to 10-30°C / min, and the cooling end temperature to 20°C;

[0019] (4) The first step is room temperature aging treatment, the aging time is 1 to 14 days;

[0020] (5) Aging heat treatment at a temperature of 100 to 300°C for 5 to 25 minutes, followed by cooling to room temperature at a rate of 10 to 20°C / minute;

[0021] (6) Second step: aging heat treatment, heat treatment temperature 50 ~ 600 ° C, heat treatment time 30 ~ 60 minutes, then cooling to room temperature at a rate of 20 ~ 40 ° C / min;

[0022] (7) The third step is aging heat treatment, with a heat treatment temperature of 50-200°C and a heat treatment time of 60-120 minutes, followed by cooling to room temperature at a rate of 30-50°C / min;

[0023] (8) The second step is room temperature aging treatment, the aging time is 1 to 10 days;

[0024] (9) A titanium alloy rod with high strength and high toughness is obtained.

[0025] In the method for preparing titanium alloy bars with high strength and high toughness, in step (3), the design of the forging die should take into account the shape and size of the final part. The forging die is usually made of a high-temperature resistant alloy to ensure wear resistance and heat resistance. The titanium alloy bar blank is placed on the spindle of a rotary machine tool for rotary forging.

[0026] In the method for preparing the titanium alloy rod with high strength and high toughness, in step (3), this step needs to be repeated until the size and shape required by the design are achieved.

[0027] The technical principle of the present invention is:

[0028] How each step and its order work

[0029] (1) Adjust the composition ratio

[0030] The microstructure is optimized by precisely adjusting the elemental composition of the alloy to meet the following mass percentages: Ti 63%-65%, Nb 22%-25%, Zr 3%-5%, Sn 7%-9%, and O 0.05%-0.2%. Specifically, optimizing the ratios of titanium (Ti), niobium (Nb), zirconium (Zr), tin (Sn), and oxygen (O) significantly improves the alloy's phase stability and eliminates property anisotropy. The preferred composition is 63.87% Ti, 24.0% Nb, 4.0% Zr, 8.0% Sn, and 0.13% O, ensuring the stability of the alloy's mechanical properties under various environmental conditions. This precise adjustment of the composition ratios optimizes the microstructure and minimizes stress concentration and interface mismatch between grains.

[0031] (2) Pressing alloy electrodes and vacuum melting

[0032] Vacuum melting technology, which melts alloy electrodes in a high vacuum environment, prevents oxidation and the introduction of other impurities, ensuring the alloy's high purity and uniformity. Vacuum melting not only promotes the full dissolution and uniform distribution of alloying elements, but also forms a fine, uniform grain structure through high-temperature melting and rapid solidification. This process optimizes the alloy's microstructure by controlling melting parameters, enhancing the material's mechanical properties and toughness.

[0033] (3) Forging and cooling

[0034] During the forging process, the forging temperature is controlled to ensure that the material is within the optimal plastic deformation temperature range. The deformation is controlled within 10-50% to avoid defects caused by excessive deformation. Rapid cooling after forging (10-30°C / minute) effectively inhibits grain growth and retains a fine and uniform grain structure. By controlling the cooling endpoint temperature to 20°C, the stability of the material at room temperature and the uniformity of mechanical properties are ensured. This step optimizes the grain size and phase distribution through precise forging and cooling control, thereby improving the comprehensive mechanical properties of the alloy.

[0035] (4) First step aging heat treatment

[0036] The first step of aging heat treatment is to further strengthen the matrix structure of the material by precipitating metastable phases. This process optimizes the distribution and size of the precipitated phase by controlling the cooling rate (10-20°C / minute), thereby improving the hardness and strength of the material. The second step of aging heat treatment further promotes the precipitation and phase transformation of the secondary phase in the alloy and optimizes the microstructure. The microstructure of the alloy is ensured to be stable and uniform by a higher aging temperature and extended aging time. The cooling rate is controlled at 20-40°C / minute to ensure the optimal size and distribution of the precipitated phase, further improving the comprehensive mechanical properties of the material. The third step of aging heat treatment is to further stabilize the microstructure of the alloy and eliminate residual stress and defects by aging at low temperature for a long time. This process ensures the long-term stability and toughness of the alloy at room temperature by a slower cooling rate (30-50°C / minute).

[0037] (8) Room temperature aging treatment

[0038] Before the aging heat treatment, a first step of room temperature aging is added for 1 to 14 days. This stabilizes the alloy structure and helps achieve the desired structure in subsequent heat treatments. A second step of room temperature aging is performed after the aging heat treatment for 1 to 10 days to further refine the microstructure and gradually eliminate residual stresses through the natural aging process, improving the material's performance stability. This natural aging step allows the alloy to achieve optimal performance without introducing additional thermal stress.

[0039] Through the aforementioned meticulous adjustment of composition ratios, rigorous vacuum melting, precisely controlled multiple forging and cooling cycles, multi-step aging heat treatment, and room-temperature aging, alloy bars with high strength and toughness are ultimately achieved. Strict parameter control at each step ensures a uniform microstructure, fine grains, and a balanced phase distribution, resulting in the material's exceptional overall mechanical properties. This combination of precisely controlled and optimized process steps significantly enhances the performance of the alloy bars, enabling them to meet the demanding high-strength and high-toughness requirements of high-end applications.

[0040] The advantages and beneficial effects of the present invention are:

[0041] 1. The present invention provides a titanium alloy bar with high strength and high toughness, the alloy has a maximum crack initiation toughness of 165.6 kJ / m 2 , the maximum expansion toughness is 241.7kJ / m 2 , with a tensile strength of 767MPa, an elongation of 17%, and an elastic modulus of 51GPa, which solves the shortcomings of poor mechanical properties of existing high-toughness alloys and expands the application capabilities of metastable β titanium alloys in high-strength and high-toughness service environments.

[0042] 2. The present invention provides a method for preparing titanium alloy rods with high strength and high toughness. This technical solution cannot contain solid solution and quenching treatments, because both solid solution treatment and quenching will destroy the required organization and structure of the alloy, and thus the alloy will not have the required high strength and high toughness. Therefore, it simplifies the existing metastable β titanium alloy preparation process and effectively improves the preparation and processing efficiency of the alloy. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 Schematic diagrams of sample orientation for alloy plate tensile and fracture toughness J-integral specimens. RD represents the forging streamline direction, ND represents the normal direction, and TD represents the direction perpendicular to the forging streamline. (a) shows a schematic diagram of the fracture toughness (CT) specimen orientation, where the first set of letters indicates the loading direction, and the second set of letters indicates the crack propagation direction (e.g., RD-TD indicates loading in the RD direction and crack propagation in the TD direction). (b) shows the TD-TD orientation diagram for the fracture toughness specimen (loading direction TD, crack propagation direction TD), (c) shows the TD-RD orientation diagram for the fracture toughness specimen (loading direction TD, crack propagation direction RD), (d) shows the RD-TD orientation diagram for the fracture toughness specimen (loading direction RD, crack propagation direction TD), and (e) shows the RD-TD orientation diagram for the plate tensile specimen (tensile direction RD, crack propagation direction TD).

[0044] Figure 2 The stress-strain curve of the alloy is shown in Figure 1. In the figure, the horizontal axis is Strain (%) and the vertical axis is strength (MPa).

[0045] Figure 3 This is the load-displacement curve of the alloy fracture toughness multi-specimen method. In the figure, the horizontal axis Load line displacement is the loading line displacement (mm), and the vertical axis Load is the tensile load (N).

[0046] Figure 4 The JR resistance curve is shown in Figure 1. In the figure, the horizontal axis Crack extension is the J integral crack extension length △a (mm), and the vertical axis J-integral is the J integral (kJ / m 2 ). DETAILED DESCRIPTION

[0047] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention and the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts should fall within the scope of protection of the present invention.

[0048] Example 1

[0049] In this embodiment, a method for preparing a titanium alloy bar with high strength and high toughness is carried out in the following steps:

[0050] (1) Adjusting the composition ratio so that the mass percentage of the elements in the alloy satisfies the following: Ti 64.8%, Nb 23%, Zr 3%, Sn 9%, O 0.2%;

[0051] (2) pressing alloy electrodes and performing vacuum melting;

[0052] (3) Forging and blanking - cooling, the initial forging temperature is 1200℃, the final forging temperature is 1000℃, the deformation is controlled to 30%, the cooling rate is controlled to 20℃ / min, and the cooling end temperature is 20℃;

[0053] (4) The first step is room temperature aging treatment, the aging time is 1 day;

[0054] (5) First step aging heat treatment, heat treatment temperature 300 ° C, heat treatment time 10 minutes, then cooling to room temperature at a rate of 10 ° C / min;

[0055] (6) Second step aging heat treatment, heat treatment temperature 350 ° C, heat treatment time 30 minutes, then cooling to room temperature at a rate of 20 ° C / min;

[0056] (7) The third step is aging heat treatment, the heat treatment temperature is 200 ° C, the heat treatment time is 60 minutes, and then cooled to room temperature at a rate of 30 ° C / min;

[0057] (8) The second step is room temperature aging treatment, the aging time is 1 day;

[0058] (9) A titanium alloy rod with high strength and high toughness is obtained.

[0059] like Figure 1 As shown in (a) and (d), the RD-TD orientation mechanical properties test was carried out, and the RD-TD orientation mechanical properties are shown in Table 1.

[0060] Example 2

[0061] In this embodiment, a method for preparing a titanium alloy bar with high strength and high toughness is carried out in the following steps:

[0062] (1) Adjust the composition ratio so that the mass percentage of the element composition of the alloy satisfies: Ti 64.95%, Nb 22.5%, Zr 3.6%, Sn 8.9%, O: 0.05%.

[0063] (2) pressing alloy electrodes and performing vacuum melting;

[0064] (3) Forging and blanking - cooling, the initial forging temperature is 1250℃, the final forging temperature is 1050℃, the deformation is controlled to 50%, the cooling rate is controlled to 30℃ / min, and the cooling end temperature is 20℃;

[0065] (4) The first step is room temperature aging treatment, the aging time is 14 days;

[0066] (5) First step aging heat treatment, heat treatment temperature 300 ° C, heat treatment time 10 minutes, then cooling to room temperature at a rate of 10 ° C / min;

[0067] (6) Second step aging heat treatment, heat treatment temperature 350 ° C, heat treatment time 30 minutes, then cooling to room temperature at a rate of 20 ° C / min;

[0068] (7) The third step is aging heat treatment, the heat treatment temperature is 200 ° C, the heat treatment time is 60 minutes, and then cooled to room temperature at a rate of 30 ° C / min;

[0069] (8) The second step is room temperature aging treatment, the aging time is 1 day;

[0070] (9) A titanium alloy rod with high strength and high toughness is obtained.

[0071] like Figure 1 As shown in (a) and (d), the RD-TD orientation mechanical properties test was carried out, and the RD-TD orientation mechanical properties are shown in Table 1.

[0072] Example 3

[0073] In this embodiment, a method for preparing a titanium alloy bar with high strength and high toughness is carried out in the following steps:

[0074] (1) The composition ratio is adjusted so that the mass percentage of the element composition of the alloy satisfies the following: Ti: 63.87%, Nb: 24%, Zr: 4%, Sn: 8%, O: 0.13%.

[0075] (2) pressing alloy electrodes and performing vacuum melting;

[0076] (3) Forging and blanking - cooling, the initial forging temperature is 900℃, the final forging temperature is 700℃, the deformation is controlled to be 10%, the cooling rate is controlled to be 10℃ / min, and the cooling end temperature is 20℃;

[0077] (4) The first step is room temperature aging treatment, the aging time is 10 days;

[0078] (5) First step aging heat treatment, heat treatment temperature 300 ° C, heat treatment time 10 minutes, then cooling to room temperature at a rate of 10 ° C / min;

[0079] (6) Second step aging heat treatment, heat treatment temperature 100 ° C, heat treatment time 30 minutes, then cooling to room temperature at a rate of 20 ° C / min;

[0080] (7) The third step is aging heat treatment, the heat treatment temperature is 200 ° C, the heat treatment time is 60 minutes, and then cooled to room temperature at a rate of 30 ° C / min;

[0081] (8) The second step is room temperature aging treatment, the aging time is 1 day;

[0082] (9) A titanium alloy rod with high strength and high toughness is obtained.

[0083] like Figure 1 As shown in (a) and (d), the RD-TD orientation mechanical properties test was carried out, and the RD-TD orientation mechanical properties are shown in Table 1.

[0084] Example 4

[0085] In this embodiment, a method for preparing a titanium alloy bar with high strength and high toughness is carried out in the following steps:

[0086] (1) The composition ratio is adjusted so that the mass percentage of the element composition of the alloy satisfies the following: Ti: 63.87%, Nb: 24%, Zr: 4%, Sn: 8%, O: 0.13%.

[0087] (2) pressing alloy electrodes and performing vacuum melting;

[0088] (3) Forging and blanking - cooling, the initial forging temperature is 1000℃, the final forging temperature is 800℃, the deformation is controlled to 20%, the cooling rate is controlled to 10℃ / min, and the cooling end temperature is 20℃;

[0089] (4) The first step is room temperature aging treatment, the aging time is 7 days;

[0090] (5) First step aging heat treatment, heat treatment temperature 300 ° C, heat treatment time 10 minutes, then cooling to room temperature at a rate of 10 ° C / min;

[0091] (6) Second step aging heat treatment, heat treatment temperature 100 ° C, heat treatment time 30 minutes, then cooling to room temperature at a rate of 20 ° C / min;

[0092] (7) The third step is aging heat treatment, the heat treatment temperature is 200 ° C, the heat treatment time is 60 minutes, and then cooled to room temperature at a rate of 30 ° C / min;

[0093] (8) The second step is room temperature aging treatment, the aging time is 1 day;

[0094] (9) A titanium alloy rod with high strength and high toughness is obtained.

[0095] like Figure 1 As shown in (a) and (b), the TD-TD orientation mechanical properties test was carried out, and the TD-TD orientation mechanical properties are shown in Table 1.

[0096] Example 5

[0097] In this embodiment, a method for preparing a titanium alloy bar with high strength and high toughness is carried out in the following steps:

[0098] (1) The composition ratio is adjusted so that the mass percentage of the element composition of the alloy satisfies the following: Ti: 63.87%, Nb: 24%, Zr: 4%, Sn: 8%, O: 0.13%.

[0099] (2) pressing alloy electrodes and performing vacuum melting;

[0100] (3) Forging and blanking - cooling, the initial forging temperature is 1100℃, the final forging temperature is 900℃, the deformation is controlled to be 40%, the cooling rate is controlled to be 30℃ / min, and the cooling end temperature is 20℃;

[0101] (4) The first step is room temperature aging treatment, the aging time is 2 days;

[0102] (5) First step aging heat treatment, heat treatment temperature 300 ° C, heat treatment time 10 minutes, then cooling to room temperature at a rate of 10 ° C / min;

[0103] (6) Second step aging heat treatment, heat treatment temperature 100 ° C, heat treatment time 30 minutes, then cooling to room temperature at a rate of 20 ° C / min;

[0104] (7) The third step is aging heat treatment, the heat treatment temperature is 200 ° C, the heat treatment time is 60 minutes, and then cooled to room temperature at a rate of 30 ° C / min;

[0105] (8) The second step is room temperature aging treatment, the aging time is 1 day;

[0106] (9) A titanium alloy rod with high strength and high toughness is obtained.

[0107] like Figure 1 As shown in (a) and (c), the TD-RD orientation mechanical properties test was carried out, and the TD-RD orientation mechanical properties are shown in Table 1.

[0108] Table 1 Mechanical properties of Ti2448 alloy

[0109]

[0110] Comparative Example 1

[0111] Pure titanium, pure niobium, and pure tantalum are mixed in appropriate proportions, with the mass fraction of Nb being 25% to 29%, the mass fraction of Ta being 14% to 20%, and the remainder being Ti. Ingots are melted and cast using a vacuum consumable arc technique. The ingots undergo a high-temperature homogenization and diffusion heat treatment to eliminate element segregation. The ingots are then hot forged, annealed, and quenched, and then cold rolled to a deformation of 40% to 50%. This embodiment does not involve rotary forging, and the resulting titanium alloy does not possess high strength and toughness.

[0112] Comparative Example 2

[0113] Five melting steps were performed using vacuum consumable electrode arc melting technology. The ingots were subjected to a high-temperature homogenization diffusion treatment at 1050 degrees Celsius for 24 hours to eliminate element segregation. The ingots were hot-forged into billets at 900 degrees Celsius. The billets were hot-rolled into thick plates at 650 degrees Celsius. The thick plates were solution treated and quenched at 900 degrees Celsius for 15 minutes in water. The quenched thick plates were cold rolled at room temperature to a cold rolling deformation of 40%. The cold-rolled plates were then subjected to a short-term heat treatment at 350 degrees Celsius for 40 minutes. This embodiment does not involve rotary forging, and the resulting titanium alloy does not possess high strength and toughness.

[0114] Comparative Example 3

[0115] The same as Example 1, except that the titanium alloy material obtained after hot forging was hot rolled at 1123K to form a bulk alloy; the resulting bulk alloy was encapsulated in a quartz tube for heat treatment at 1123K for 24 hours, followed by air cooling; and the cooled bulk alloy was cold rolled in the same direction at room temperature with an 8% reduction. This example does not involve rotary forging, and the resulting titanium alloy does not possess high strength and toughness.

[0116] like Figure 2 As shown, it can be seen from the high strength performance curve of the alloy in Example 3 that the tensile strength of the alloy is greater than 700 MPa, and it has high strength characteristics.

[0117] like Figure 3 As shown in FIG, it can be seen from the load-displacement curve of the fracture toughness multi-specimen method of the alloy in Example 3 that during the loading process, the sample in Example 3 (RD-TD orientation) still has a large plastic deformation after exceeding the maximum load. The plastic deformation can enhance toughness. The larger the plastic deformation area, the higher the J integral value.

[0118] like Figure 4 As shown in the JR resistance curve of the alloy in Example 3, it can be seen that the crack initiation toughness of the alloy in RD-TD orientation is 165.6 kJ / m 2 , expansion toughness is 241.7kJ / m 2 , the alloy is characterized by high toughness.

[0119] The implementation results show that the present invention does not involve the preparation of porous materials, solid solution, water quenching and other processes, and does not require the use of the phase transformation from the parent phase to the martensite phase to achieve high toughness. An alloy material with both high strength and high toughness is obtained through a completely different working principle.

Claims

1. A method for preparing a titanium alloy bar with high strength and high toughness, characterized in that: The titanium alloy bar contains a metastable bcc structured β phase. The composition of the titanium alloy is as follows by mass percentage: Ti 63%~65%, Nb 22%~25%, Zr3%~5%, Sn 7%~9%, and O 0.05%~0.2%. The crack initiation toughness of the titanium alloy is 56.2~165.6kJ / m 2 , crack growth toughness is 67.0~241.7 kJ / m 2 , tensile strength 650~800MPa, elongation 5%~17%, elastic modulus 50~60GPa; The method for preparing the titanium alloy bar with high strength and high toughness is carried out in the following steps: (1) Adjust the composition ratio so that the mass percentage of the element composition of the titanium alloy meets the following requirements: Ti 63%~65%, Nb 22%~25%, Zr 3%~5%, Sn 7%~9%, O 0.05%~0.2%; (2) Pressing the alloy electrode and vacuum melting it for 2 to 6 times; (3) Forging and blanking - cooling, control the forging temperature to 700~1250℃, control the deformation to 10~50%, control the cooling rate to 10~30℃ / min, and the cooling end temperature to 20℃; (4) The first step is room temperature aging treatment, the aging time is 1 to 14 days; (5) The first step is aging heat treatment, with a heat treatment temperature of 300 °C and a heat treatment time of 10 minutes, followed by cooling to room temperature at a rate of 10 °C / minute; (6) Second step aging heat treatment, heat treatment temperature 350℃, heat treatment time 30 minutes, then cooling to room temperature at a rate of 20℃ / min; or heat treatment temperature 100℃, heat treatment time 30 minutes, then cooling to room temperature at a rate of 20℃ / min; (7) The third step is aging heat treatment, the heat treatment temperature is 200 ° C, the heat treatment time is 60 minutes, and then cooled to room temperature at a rate of 30 ° C / minute; (8) The second step is room temperature aging treatment, the aging time is 1 to 10 days; (9) A titanium alloy rod with high strength and high toughness is obtained.

2. The method for preparing a titanium alloy bar with high strength and high toughness according to claim 1, characterized in that: In step (3), the forging die design should take into account the shape and size of the final part. The forging die is made of a high-temperature resistant alloy to ensure wear resistance and heat resistance. The titanium alloy bar blank is placed on the spindle of a rotary machine tool for rotary forging.

3. The method for preparing a titanium alloy bar having high strength and high toughness according to claim 1, wherein: In step (3), this step needs to be repeated until the design size and shape are achieved.

4. The method for preparing a titanium alloy bar with high strength and high toughness according to claim 1, characterized in that: The composition of the titanium alloy rod is as follows: Ti 63.87%, Nb 24.0%, Zr 4.0%, Sn 8.0%, and O 0.13%.

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