An ordered phase-strengthened titanium alloy with improved oxidation resistance and its preparation method

Abstract

This invention discloses an ordered phase-strengthened titanium alloy with improved oxidation resistance and its preparation method, belonging to the technical field of titanium-based metal materials. The method involves using a laser cladding process with a mass ratio of (0.85~1.15):(0.85~1.15) to clad Ti particles and Ti-Sn-Al compound particles onto the surface of the ordered phase-strengthened titanium alloy, forming a base layer coating. Then, using the same laser cladding process, Ti-Sn-Al compound particles are clad onto the base layer coating, forming a double-layer Ti-Sn-Al intermetallic compound coating on the surface of the ordered phase-strengthened titanium alloy. The ordered phase-strengthened titanium alloy with the double-layer Ti-Sn-Al intermetallic compound coating is then subjected to slow cooling and air cooling sequentially to obtain an ordered phase-strengthened titanium alloy with improved oxidation resistance, effectively enhancing its high-temperature oxidation resistance and long-term service capability.

Description

Technical Field

[0001] This invention belongs to the field of titanium-based metal materials technology, specifically relating to an ordered phase-strengthened titanium alloy with improved oxidation resistance and its preparation method. Background Technology

[0002] With the increasing demands for high-temperature structural components in aerospace, energy, and other fields, there is a need to develop titanium alloys that combine lightweight, high strength, high-temperature stability, and excellent oxidation resistance. When traditional titanium alloys are used for extended periods above 600°C, a porous and thermodynamically unstable oxide film, such as TiO2, easily forms on the surface. This film cannot effectively prevent oxygen from diffusing inward, leading to continuous oxidation of the substrate and a sharp decline in performance, severely limiting their application and long-term service in high-temperature environments.

[0003] To improve the high-temperature oxidation resistance of titanium alloys, researchers have proposed several solutions, mainly including alloying modification and surface coating protection. Alloying modification primarily involves adding small amounts of highly reactive elements (such as Cr, Si, and Nb) to the titanium alloy. These elements preferentially react with oxygen during high-temperature oxidation to form a continuous and dense composite oxide film, effectively preventing oxygen diffusion and thus significantly improving the alloy's oxidation resistance. However, the amount of these elements added must be strictly controlled; otherwise, it can easily induce the precipitation of brittle phases and lead to deterioration of ductility and toughness, affecting the overall mechanical properties of the alloy. Therefore, due to limitations in the amount of elements added, the improvement in the high-temperature oxidation resistance of the alloy is also limited.

[0004] Surface coating protection primarily involves applying one or more layers of high-temperature resistant, oxidation-resistant materials to the alloy surface to prevent direct contact between oxygen (O) and the alloy substrate, thereby significantly improving its high-temperature oxidation resistance. Commonly used coatings include nickel-based alloy coatings (such as NiCrAlY and NiCoCrAlY systems), TiAl metal compound coatings (such as TiAl systems), and high-entropy alloy and ceramic coatings. These coatings can form a continuous and dense oxide film (such as Al2O3, NiAl2O4, etc.) at high temperatures, effectively inhibiting oxygen diffusion and substrate oxidation. Compared to alloying modification, coatings achieve superior oxidation resistance with minimal impact on the substrate composition. However, surface coating protection places stringent requirements on the physicochemical properties of the coating. Firstly, the coating itself must possess strong oxidation resistance and thermal stability; secondly, it must have strong adhesion to the substrate and a low difference in thermal expansion coefficients. Otherwise, the surface coating is prone to cracking and peeling during use, limiting its long-term reliability and safety.

[0005] For the novel Ti-Sn-Al ordered phase reinforced high-temperature titanium alloys developed in recent years, their long-term service temperature reaches above 850℃. Current high-temperature oxide coatings suffer from insufficient oxidation resistance, thermal stability, and poor adhesion to the alloy. Therefore, providing a novel coating and application method suitable for Ti-Sn-Al ordered phase reinforced high-temperature titanium alloys is of great significance for the practical application and future development of these alloys. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention provides an ordered phase-strengthened titanium alloy with improved oxidation resistance and its preparation method. Specifically for ordered phase-strengthened titanium alloys serving at high temperatures, particularly novel Ti-Sn-Al ordered phase-strengthened titanium alloys capable of operating above 850°C, this invention leverages the excellent oxidation resistance and high-temperature stability of the Ti-Sn-Al intermetallic compound itself, as well as its good bonding ability with the homomorphic Ti matrix. A Ti-Sn-Al intermetallic compound coating is prepared on the surface of the ordered phase-strengthened titanium alloy to enhance the alloy's oxidation resistance.

[0007] The present invention is implemented using the following technical solutions: A method for preparing an ordered phase-strengthened titanium alloy with improved oxidation resistance, specifically including the following steps: Step 1: Using a laser cladding process, Ti particles and Ti-Sn-Al compound particles are clad onto the surface of an ordered phase-strengthened titanium alloy at a mass ratio of (0.85~1.15):(0.85~1.15) to form an underlayer coating. Step 2: Using laser cladding technology, Ti-Sn-Al compound particles are clad onto the bottom coating to form a double-layer Ti-Sn-Al intermetallic compound coating on the ordered phase-strengthened titanium alloy surface. Step 3: The ordered phase-strengthened titanium alloy with a double-layer Ti-Sn-Al intermetallic compound coating on its surface is subjected to slow cooling and air cooling in sequence to obtain an ordered phase-strengthened titanium alloy with improved oxidation resistance.

[0008] A further improvement of the present invention is that: Step 1 involves grinding and cleaning the surface of the ordered phase-strengthened titanium alloy, controlling the surface roughness to be 20~50 μm, and then cladding Ti particles and Ti-Sn-Al compound particles.

[0009] The ordered phase strengthened titanium alloy mentioned in step 1 is a Ti-Sn-Al ordered phase strengthened titanium alloy or an α2-Ti3Al ordered phase strengthened titanium alloy.

[0010] The Ti-Sn-Al compound mentioned in steps 1 and 2 is one or both of Ti8AlSn and Ti4AlSn2.

[0011] In the underlayer coating described in step 1, the total amount of Ti, Al, and Sn is 100% by atomic percentage, of which Al is 5%~8% and Sn is 5%~12%. In step 2, a surface coating is formed on the underlayer coating. The underlayer coating and the surface coating constitute a double-layer Ti-Sn-Al intermetallic compound coating. In the surface coating, the total amount of Ti, Al, and Sn is 100% by atomic percentage, of which Al is 10%~15% and Sn is 10%~30%.

[0012] The thickness of the double-layer Ti-Sn-Al intermetallic compound coating described in step 2 is 1~1.5 mm.

[0013] The slow cooling described in step 3 is carried out in a resistance furnace at 150~200℃ for 2~3 hours, and then the alloy is removed from the furnace and air-cooled to room temperature to obtain an ordered phase-strengthened titanium alloy with improved oxidation resistance.

[0014] An ordered phase-strengthened titanium alloy with improved oxidation resistance obtained by the preparation method of the ordered phase-strengthened titanium alloy with improved oxidation resistance described in any one of the above methods.

[0015] An ordered phase-strengthened titanium alloy with improved oxidation resistance includes an ordered phase-strengthened titanium alloy and a bottom coating and a surface coating sequentially clad on the surface of the titanium alloy. The bottom coating is formed by Ti particles and Ti-Sn-Al compound particles in a mass ratio of (0.85~1.15):(0.85~1.15), and the surface coating is formed by Ti-Sn-Al compound particles.

[0016] Compared with the prior art, the present invention has the following beneficial technical effects: This invention discloses a method for preparing ordered phase-reinforced titanium alloys with enhanced oxidation resistance. A Ti-Sn-Al intermetallic compound coating is prepared on the surface of the ordered phase-reinforced titanium alloy. Leveraging the excellent oxidation resistance, thermal stability, and good bonding ability between the Ti-Sn-Al intermetallic compound and the Ti matrix, the oxidation resistance of the titanium alloy is effectively improved. Specifically, the presence of high Al and Sn content and their interaction with Ti result in excellent oxidation resistance of the Ti-Sn-Al intermetallic compound (ordered phase) at temperatures above 850°C. At high temperatures, a dense and stable (Ti,Sn)₂O and Al₂O₃ film mainly forms on the surface of the Ti-Sn-Al intermetallic compound. Unlike the loose TiO₂ film, this film effectively isolates oxygen from further contact with the substrate. The (Ti,Sn)₂O also improves the adhesion of the oxide layer to the substrate surface and slows down the diffusion rate of O atoms, inhibiting the oxidation process of the substrate. Furthermore, Ti-Sn-Al intermetallic compounds possess a highly ordered crystal structure and strong chemical bonding, exhibiting excellent thermal stability. Simultaneously, they share the same hexagonal crystal structure as Ti crystals, resulting in similar crystal structures and strong adhesion to titanium alloy substrates (especially Ti-Sn-Al ordered phase reinforced alloys). This invention employs laser cladding to prepare a double-layer coating, designing a transition layer that neutralizes the Ti matrix composition and the Ti-Sn-Al intermetallic compound composition as the bottom coating that directly contacts the titanium alloy, further enhancing the bonding between the coating and the titanium alloy substrate.

[0017] The titanium alloy with a Ti-Sn-Al intermetallic compound coating prepared by this invention exhibits excellent high-temperature oxidation resistance. It maintains a complete and dense oxide layer under conditions of 850℃ / 100 h and 900℃ / 50 h, with oxidation weight gain not exceeding 2 mg / cm³. 2 Therefore, it can be used stably in service environments of 850℃ and above. Compared with traditional anti-oxidation coatings and surface coating protection methods, it shows obvious advantages and can ensure that the new ordered phase titanium alloy can be used stably for a long time in high temperature environments without surface peeling and performance degradation due to oxidation. This is conducive to promoting the application and development of this alloy in aerospace and other fields. Attached Figure Description

[0018] Figure 1 The image shows the macroscopic surface of the novel ordered phase-reinforced titanium alloy with a Ti-Sn-Al intermetallic compound coating obtained in Example 1 after long-term high-temperature oxidation. Figure 2 This is a macroscopic surface image of the novel ordered phase-reinforced titanium alloy with a Ti-Sn-Al intermetallic compound coating obtained in Example 2 after long-term high-temperature oxidation. Figure 3This is a macroscopic surface image of a conventional ordered phase reinforced titanium alloy with a Ti-Sn-Al intermetallic compound coating obtained in Example 3 after long-term high-temperature oxidation. Figure 4 The image shows the macroscopic surface of the titanium alloys with Ti-Al alloy coatings prepared in Comparative Examples 1-3 after long-term high-temperature oxidation. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to specific embodiments and accompanying drawings. The specific embodiments described below are only for further illustrating the present invention and are not intended to limit the scope of protection of the present invention.

[0020] Unless otherwise defined, all terms used herein shall be interpreted in accordance with their meaning as commonly understood by those skilled in the art. Unless otherwise specified, all raw materials, reagents, instruments, and equipment used in this invention may be obtained commercially or prepared by existing methods.

[0021] A method for improving the oxidation resistance of ordered phase-reinforced titanium alloys includes the following steps: (1) The surface of the high-temperature titanium alloy strengthened by ordered phase (including Ti-Sn-Al ordered phase strengthening and α2-Ti3Al ordered phase strengthening) is polished and cleaned, and the surface roughness is controlled in the range of 20~50 μm. (2) Ti particles with a mass ratio of (0.85~1.15): (0.85~1.15) and Ti-Sn-Al compound particles (which can be prepared by mechanical alloying) are first clad onto the surface of titanium alloy as a base coating by laser cladding process; (3) Then, Ti-Sn-Al compound particles are further clad as a surface coating. The two-step cladding process is carried out in a protective atmosphere of high-purity argon (≥99.99%) to form a double-layer composite Ti-Sn-Al intermetallic compound coating. The Ti-Sn-Al compound is any one or both of the two hexagonal crystal system compounds Ti8AlSn and Ti4AlSn2. The specific composition of the Ti-Sn-Al intermetallic compound coating is as follows: the bottom layer composition, by atomic percentage, is 100% of Ti, Al and Sn, of which Al: 5%~8% and Sn: 5%~12%; the surface composition, by atomic percentage, is 100% of Ti, Al and Sn, of which Al: 10%~15% and Sn: 10%~30%. The total thickness of the Ti-Sn-Al intermetallic compound coating prepared on the titanium alloy surface is 1~1.5 mm.

[0022] For Ti-Sn-Al ordered phase strengthened titanium alloys, the Ti-Sn-Al compound particles used in the coating must be consistent with the composition of the ordered strengthening phase in the titanium alloy; for other ordered phase strengthened titanium alloys, there are no special requirements for the Ti-Sn-Al compound particles used in the coating.

[0023] (4) After cladding, the titanium alloy is placed in a resistance furnace at 150℃~200℃ for slow cooling for 2~3 hours, and then taken out of the furnace and air-cooled to room temperature.

[0024] Titanium alloys with Ti-Sn-Al compound coatings exhibit excellent high-temperature oxidation resistance. The oxide films formed at 850℃ / 100h and 900℃ / 50h are both complete and dense, with minimal oxidation weight gain, not exceeding 2 mg / cm³. 2 .

[0025] Example 1 A Ti-Sn-Al intermetallic compound coating was prepared on the surface of a Ti8AlSn ordered phase reinforced titanium alloy. The chemical composition, by atomic percentage, was as follows: Undercoat: Al: 5%, Sn: 5%, balance Ti, with unavoidable trace impurities, typically less than 0.1%; Surface coating: Al: 10%, Sn: 10%, balance Ti, with unavoidable trace impurities, typically less than 0.1%. The specific steps are as follows: (1) The surface of Ti8AlSn ordered phase reinforced titanium alloy was polished and cleaned, and the surface roughness was controlled to 50 μm; (2) Ti particles and Ti8AlSn compound particles with a mass ratio of 1:1 are first clad onto the surface of titanium alloy using a laser cladding machine as a base coating with a coating thickness of 0.5 mm. (3) Then, Ti8AlSn compound particles were further clad as a surface coating with a thickness of 1.0 mm. The entire two-step cladding process was carried out in a protective atmosphere of high-purity argon (≥99.99%). (4) After cladding, the titanium alloy is placed in a resistance furnace at 200℃ and slowly cooled for 3 hours, and then taken out of the furnace and air-cooled to room temperature.

[0026] Test characterization: The above-mentioned samples, cut by wire cutting, were subjected to oxidation experiments in a resistance furnace, held at 850℃ / air for 100 h and at 900℃ / air for 50 h, respectively. Figure 1 As shown, the oxide layers on the alloy surfaces after oxidation under two different conditions are complete and dense, without cracking or peeling. Furthermore, the alloy mass before and after oxidation was characterized, and the calculated weight gain under oxidation conditions of 850℃ / 100 h was approximately 1.64 mg / cm³. 2 The oxidative weight gain at 900℃ for 50 h was approximately 1.69 mg / cm³. 2The above results demonstrate that Ti8AlSn ordered phase reinforced titanium alloys with Ti-Sn-Al intermetallic compound coatings exhibit excellent oxidation resistance under high-temperature conditions.

[0027] Example 2 A Ti-Sn-Al intermetallic compound coating was prepared on the surface of a Ti4AlSn2 ordered phase reinforced titanium alloy. The chemical composition, by atomic percentage (at.%), was as follows: Undercoat: Al: 8%, Sn: 12%, balance Ti, with unavoidable trace impurities, typically less than 0.1%; Surface coating: Al: 15%, Sn: 30%, balance Ti, with unavoidable trace impurities, typically less than 0.1%. The specific steps are as follows: (1) The surface of Ti4AlSn2 ordered phase reinforced titanium alloy was polished and cleaned, and the surface roughness was controlled to 30 μm; (2) Ti particles and Ti4AlSn2 compound particles with a mass ratio of 1:1 are first clad onto the surface of titanium alloy as a base layer using a laser cladding machine, with a coating thickness of 0.5 mm; (3) Then, Ti4AlSn2 compound particles were further clad as a surface coating with a thickness of 1.0 mm. The entire two-step cladding process was carried out under a protective atmosphere of high-purity argon (≥99.99%). (4) After cladding, the titanium alloy is placed in a resistance furnace at 200℃ and slowly cooled for 3 hours, and then taken out of the furnace and air-cooled to room temperature.

[0028] Test characterization: The above-mentioned samples, cut by wire cutting, were subjected to oxidation experiments in a resistance furnace, held at 850℃ / air for 100 h and at 900℃ / air for 50 h, respectively. Figure 2 As shown, the oxide layers on the alloy surfaces after oxidation under two different conditions are complete and dense, without cracking or peeling. Furthermore, the alloy mass before and after oxidation was characterized, and the calculated weight gain under oxidation conditions of 850℃ / 100 h was approximately 1.32 mg / cm³. 2 The oxidative weight gain under 900℃ / 50 h conditions was approximately 1.35 mg / cm³. 2 The above results demonstrate that Ti4AlSn2 ordered phase reinforced titanium alloys with Ti-Sn-Al intermetallic compound coatings exhibit excellent oxidation resistance under high-temperature conditions.

[0029] Example 3 A Ti-Sn-Al intermetallic compound coating was prepared on the surface of an α2-Ti3Al ordered phase reinforced titanium alloy. The chemical composition, by atomic percentage (at.%), was as follows: Undercoat: Al: 5.5%, Sn: 8%, balance Ti, with unavoidable trace impurities, typically less than 0.1%; Surface coating: Al: 12%, Sn: 18%, balance Ti, with unavoidable trace impurities, typically less than 0.1%. The specific steps are as follows: (1) The surface of the α2-Ti3Al ordered phase reinforced titanium alloy was polished and cleaned, and the surface roughness was controlled to 20 μm; (2) Using a laser cladding machine, Ti particles with a mass ratio of 1:1 and Ti8AlSn and Ti4AlSn2 compounds with a mass ratio of 1:1 are first clad onto the surface of the titanium alloy as a base layer coating with a coating thickness of 0.5 mm. (3) Subsequently, a mixture of Ti8AlSn and Ti4AlSn2 compounds in a mass ratio of 1:1 was further clad as a surface coating with a coating thickness of 0.5 mm. The entire two-step cladding process was carried out under a protective atmosphere of high-purity argon (≥99.99%). (4) After cladding, the titanium alloy is placed in a 150°C resistance furnace for slow cooling for 2 hours, and then taken out of the furnace and air-cooled to room temperature.

[0030] Test characterization: The above-mentioned samples, cut by wire cutting, were subjected to oxidation experiments in a resistance furnace, held at 850℃ / air for 100 h and at 900℃ / air for 50 h, respectively. Figure 3 As shown, the oxide layers on the alloy surfaces after oxidation under two different conditions are complete and dense, without cracking or peeling. Furthermore, the alloy mass before and after oxidation was characterized, and the calculated weight gain under oxidation conditions of 850℃ / 100 h was approximately 1.71 mg / cm³. 2 The oxidative weight gain at 900℃ for 50 h was approximately 1.82 mg / cm³. 2 The above results demonstrate that Ti3Al ordered phase reinforced titanium alloys with Ti-Sn-Al intermetallic compound coatings exhibit excellent oxidation resistance under high-temperature conditions.

[0031] Comparative Example 1 A Ti-Al alloy coating was prepared on the surface of a Ti8AlSn ordered phase reinforced titanium alloy. Its chemical composition, by atomic percentage (at.%), was: Al: 50%, with the balance being Ti, and unavoidable trace impurity elements, typically less than 0.1%. The specific steps are as follows: (1) Grind and clean the surface of the ordered phase reinforced titanium alloy, and control the surface roughness within the range of 10 μm; (2) TiAl particles are clad onto the surface of titanium alloy as a coating by laser cladding machine. The coating thickness is 1.5 mm. The entire cladding process is carried out in a protective atmosphere of high-purity argon (≥99.99%). (3) After cladding, the titanium alloy is placed in a resistance furnace at 200℃ and slowly cooled for 3 hours, and then taken out of the furnace and air-cooled to room temperature.

[0032] Comparative Example 2 A Ti-Al alloy coating was prepared on the surface of a Ti4AlSn2 ordered phase reinforced titanium alloy. Its chemical composition, by atomic percentage (at.%), was: Al: 50%, with the balance being Ti, and unavoidable trace impurities, typically less than 0.1%. The specific steps are as follows: (1) Grind and clean the surface of the ordered phase reinforced titanium alloy, and control the surface roughness within the range of 25 μm; (2) TiAl particles are clad onto the surface of titanium alloy as a coating by laser cladding machine. The coating thickness is 1.5 mm. The entire cladding process is carried out in a protective atmosphere of high-purity argon (≥99.99%). (3) After cladding, the titanium alloy is placed in a resistance furnace at 200℃ and slowly cooled for 3 hours, and then taken out of the furnace and air-cooled to room temperature.

[0033] Comparative Example 3 A Ti-Al alloy coating was prepared on the surface of a Ti3Al ordered phase strengthened titanium alloy. Its chemical composition, by atomic percentage (at.%), was: Al: 50%, with the balance being Ti, and unavoidable trace impurity elements, typically less than 0.1%. The specific steps are as follows: (1) Grind and clean the surface of the ordered phase reinforced titanium alloy, and control the surface roughness within the range of 50 μm; (2) TiAl particles are clad onto the surface of titanium alloy as a coating by laser cladding machine. The coating thickness is 1.5 mm. The entire cladding process is carried out in a protective atmosphere of high-purity argon (≥99.99%). (3) After cladding, the titanium alloy is placed in a resistance furnace at 200℃ and slowly cooled for 3 hours, and then taken out of the furnace and air-cooled to room temperature.

[0034] Test characterization: Three samples cut from the wire-cut portion were subjected to oxidation experiments in a resistance furnace and held at 850℃ / air for 100 h. For example... Figure 4 As shown, the oxide layers on the surfaces of all three alloys exhibit cracking or peeling. Furthermore, characterization of the alloy mass before and after oxidation revealed that the weight gain of the three alloys under oxidation conditions of 850℃ / 100 h exceeded 4 mg / cm³. 2 (Including the mass of the detached oxide layer).

[0035] Clearly, the alloys prepared in the comparative examples exhibit weaker oxidation resistance at high temperatures compared to the alloys prepared in the examples. Therefore, the Ti-Sn-Al intermetallic compound coating and surface coating protection method designed using the technical solution of this invention can effectively improve the oxidation resistance of alloys at high temperatures compared to traditional Ti-Al alloy coatings, providing a foundation for the long-term service of ordered phase-strengthened titanium alloys at high temperatures.

Claims

1. A method for preparing an ordered phase-strengthened titanium alloy with improved oxidation resistance, characterized in that, Includes the following steps: S1, in a mass ratio of (0.85~1.15):(0.85~1.15), a laser cladding process is used to clad Ti particles and Ti-Sn-Al compound particles onto the surface of an ordered phase-strengthened titanium alloy to form an underlayer coating. S2 employs a laser cladding process to clad Ti-Sn-Al compound particles onto the bottom coating, forming a double-layer Ti-Sn-Al intermetallic compound coating on the ordered phase-strengthened titanium alloy surface. S3, ordered phase-strengthened titanium alloys with a double-layer Ti-Sn-Al intermetallic compound coating on the surface are subjected to slow cooling and air cooling in sequence to obtain ordered phase-strengthened titanium alloys with improved oxidation resistance.

2. The method for preparing the ordered phase-strengthened titanium alloy with improved oxidation resistance according to claim 1, characterized in that, S1 first grinds and cleans the surface of the ordered phase-strengthened titanium alloy, controlling the surface roughness to 20~50 μm, and then clads Ti particles and Ti-Sn-Al compound particles.

3. The method for preparing the ordered phase-strengthened titanium alloy with improved oxidation resistance according to claim 1, characterized in that, The ordered phase strengthened titanium alloy mentioned in S1 is a Ti-Sn-Al ordered phase strengthened titanium alloy or an α2-Ti3Al ordered phase strengthened titanium alloy.

4. The method for preparing the ordered phase-strengthened titanium alloy with improved oxidation resistance according to claim 1, characterized in that, The Ti-Sn-Al compounds mentioned in S1 and S2 are one or both of Ti8AlSn and Ti4AlSn2.

5. The method for preparing the ordered phase-strengthened titanium alloy with improved oxidation resistance according to claim 1, characterized in that, In the underlying coating described in S1, the total amount of Ti, Al and Sn is 100% by atomic percentage, of which Al is 5%~8% and Sn is 5%~12%.

6. The method for preparing the ordered phase-strengthened titanium alloy with improved oxidation resistance according to claim 1, characterized in that, S2 forms a surface coating on the bottom coating. The bottom coating and the surface coating constitute a double-layer Ti-Sn-Al intermetallic compound coating. In the surface coating, the total amount of Ti, Al and Sn is 100% by atomic percentage, of which Al is 10%~15% and Sn is 10%~30%.

7. The method for preparing the ordered phase-strengthened titanium alloy with improved oxidation resistance according to claim 1, characterized in that, The thickness of the double-layer Ti-Sn-Al intermetallic compound coating described in S2 is 1~1.5 mm.

8. The method for preparing the ordered phase-strengthened titanium alloy with improved oxidation resistance according to claim 1, characterized in that, The slow cooling described in S3 is carried out in a resistance furnace at 150~200℃ for 2~3 hours, and then the alloy is air-cooled to room temperature to obtain an ordered phase-strengthened titanium alloy with improved oxidation resistance.

9. An ordered phase-strengthened titanium alloy with improved oxidation resistance obtained by the preparation method of the ordered phase-strengthened titanium alloy with improved oxidation resistance according to any one of claims 1 to 8, characterized in that, The alloy comprises an ordered phase-strengthened titanium alloy and an underlayer coating and a surface coating sequentially clad on the surface of the titanium alloy. The underlayer coating is formed by Ti particles and Ti-Sn-Al compound particles in a mass ratio of (0.85~1.15):(0.85~1.15), and the surface coating is formed by Ti-Sn-Al compound particles.

10. The ordered phase-strengthened titanium alloy with improved oxidation resistance according to claim 9, characterized in that, The alloy maintained a complete and dense oxide layer under both the first service environment of 850℃ and 100 h, and the second service environment of 900℃ and 50 h, with an oxidation weight gain not exceeding 2 mg / cm³. 2 .

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