Ultrahigh-strength titanium alloy based on high entropy, preparation method and application

Abstract

The invention belongs to the field of material science and engineering, and particularly relates to a high-entropy-based ultrahigh-strength titanium alloy, a preparation method and application. A preparation method of an ultrahigh-strength titanium alloy based on high entropy comprises the following steps that S1, high-purity titanium, aluminum, vanadium, chromium, zirconium and molybdenum are mixed to obtain raw materials, then the raw materials are smelted and subjected to rapid solidification casting to obtain an alloy cast ingot, and the alloy cast ingot is subjected to homogenizing annealing and heat preservation to obtain the homogenized and annealed alloy cast ingot; and S2, the alloy ingot obtained after homogenizing annealing in the S1 is subjected to thermal mechanical machining, the alloy obtained after thermal machining is obtained through thermal mechanical deformation, then solution treatment, cooling and aging treatment are conducted, and the ultrahigh-strength titanium alloy based on high entropy is obtained. The ultrahigh-strength titanium alloy provided by the invention has excellent high-temperature performance, excellent fatigue resistance, corrosion resistance and oxidation resistance; and the method can be widely applied to the fields of aerospace and biomedical treatment.

Description

Technical Field

[0001] The present invention belongs to the field of material science and engineering, and specifically relates to an ultra-high strength titanium alloy based on high entropy, a preparation method and an application thereof. Background Art

[0002] The present invention belongs to the field of material science, and specifically relates to an ultra-high strength titanium alloy based on high entropy design and a preparation method thereof.

[0003] Titanium alloys have been widely used in aerospace, defense industry, biomedicine and other fields due to their excellent specific strength, corrosion resistance and biocompatibility. However, there are still bottlenecks in the performance improvement of traditional titanium alloys under certain extreme working conditions (such as high temperature, high pressure and strong stress). In recent years, with the continuous advancement of materials science, high entropy alloys (HEAs), as a new material design concept, have shown excellent mechanical properties and high temperature resistance by introducing multiple elements to form a complex solid solution structure. The unique characteristics of this multi-component alloy provide a new direction for improving the performance of titanium alloys.

[0004] The present invention develops an ultra-high strength titanium alloy based on the high entropy design concept. By introducing multiple elements and utilizing the high entropy effect formed by them, the mechanical properties and high temperature stability of the titanium alloy are significantly improved. The titanium alloy prepared by the present invention has higher strength, toughness and high temperature resistance while maintaining the advantages of traditional titanium alloys, and is suitable for applications under extreme working conditions. Summary of the invention

[0005] In view of the deficiencies of the prior art, the present invention provides a method for preparing an ultra-high strength titanium alloy based on high entropy, comprising the following steps:

[0006] S1: mixing high-purity titanium, aluminum, vanadium, chromium, zirconium and molybdenum to obtain raw materials, then smelting the raw materials, and then rapidly solidifying and casting to obtain alloy ingots, and homogenizing annealing the alloy ingots, and heat-insulating to obtain homogenizing annealed alloy ingots;

[0007] S2: The homogenized annealed alloy ingot of S1 is subjected to thermomechanical processing to obtain a hot-processed alloy through thermomechanical deformation, and then subjected to solid solution treatment, cooling, and aging treatment to obtain an ultra-high strength titanium alloy based on high entropy.

[0008] Furthermore, the titanium described in S1 accounts for 45% to 55%, the aluminum accounts for 5% to 15%, the vanadium accounts for 10% to 20%, the chromium accounts for 5% to 15%, the zirconium accounts for 5% to 10%, and the molybdenum accounts for 5% to 15%.

[0009] Furthermore, the smelting temperature described in S1 is 1600°C, the holding time is 60h, and the holding temperature is 1000°C.

[0010] Furthermore, the annealing temperature described in S1 is 1000°C.

[0011] Furthermore, the temperature of the solution treatment in S2 is 950°C.

[0012] Furthermore, the thermomechanical processing described in S2 is any one of hot rolling and forging.

[0013] An ultra-high strength titanium alloy based on high entropy.

[0014] An application of an ultra-high strength titanium alloy based on high entropy, wherein the ultra-high strength titanium alloy based on high entropy is used in the preparation of aviation engines, high-temperature structural parts, armor protection materials, and biological implants.

[0015] Beneficial Effects

[0016] (1) Through the preparation method of a high-entropy ultra-high-strength titanium alloy provided by the present invention, the yield strength and tensile strength of the material are significantly improved through high-entropy design, and at the same time, it has excellent hardness and is suitable for application scenarios with high stress and high strength requirements. It has excellent high-temperature performance, and the alloy maintains good strength and stability at high temperatures, which is suitable for the manufacture of key components under high-temperature conditions such as aircraft engines and gas turbines; and excellent fatigue resistance. Through reasonable element combination and organizational structure control, the titanium alloy of the present invention has excellent fatigue life and is suitable for key applications that withstand long-term repeated stress; it also has corrosion resistance and oxidation resistance: the alloy exhibits excellent corrosion resistance in complex environments and is suitable for applications in marine engineering and chemical equipment.

[0017] (2) Through the application of an ultra-high strength titanium alloy based on high entropy provided by the present invention, the ultra-high strength titanium alloy can be used to manufacture key components under extreme working conditions such as aircraft engines and high-temperature structural parts; and can also be used to manufacture armor protection materials and high-strength structural parts; and used to manufacture biological implants, such as artificial joints and bone plates, to improve their strength and durability. DETAILED DESCRIPTION

[0018] The following will be combined with embodiments 1 to 3 of the present invention to clearly and completely describe the technical solution of the present invention. Obviously, the described embodiments 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 ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] The present invention aims to develop a titanium alloy material with ultra-high strength, high temperature resistance and excellent fatigue resistance through the high entropy alloy design concept. The titanium alloy of the present invention significantly improves the comprehensive mechanical properties of the material through reasonable multi-element alloying and structural optimization, while maintaining the lightness and corrosion resistance of the titanium alloy. By optimizing the composition design and controlling the preparation process, the ultra-high strength titanium alloy proposed by the present invention is suitable for industrial applications and has broad application prospects in high-tech fields such as aerospace.

[0020] Combining the design principles of high entropy alloys, the present invention introduces multiple elements and utilizes the unique effects of high entropy alloys to improve the performance of titanium alloys. The design principles of high entropy alloys are as follows:

[0021] High entropy effect: In a multi-component alloy system, the mixing entropy of each element is significantly improved, which inhibits the formation of intermetallic compounds, forms a simple solid solution structure, and enhances the strength and toughness of the material; Crystal structure stability: High entropy alloys enhance the stability of the crystal structure and reduce grain boundary sliding through the uniform distribution of multiple elements, which helps to improve the creep resistance of the material; Severe lattice distortion effect: The introduction of multiple elements causes the lattice to be distorted, thereby increasing the difficulty of dislocation movement and improving the hardness and strength of the alloy; Slow diffusion effect: Due to the simultaneous presence of multiple elements, the diffusion rate between atoms is slowed down, which significantly improves the material's high temperature resistance and fatigue resistance.

[0022] The present invention provides a method for preparing an ultra-high strength titanium alloy based on high entropy, comprising the following steps:

[0023] S1: First, high-purity titanium, aluminum, vanadium, chromium, zirconium and molybdenum are weighed and then mixed to obtain raw materials. In order to ensure the purity of the alloy, high-purity metal raw materials of more than 99.9% are used. The weighed raw materials are then smelted in a vacuum induction furnace to ensure uniform mixing of the elements. During the smelting process, argon protection is used to prevent oxidation. After the smelting is completed, rapid solidification casting is performed to form a preliminary alloy ingot, and then the ingot is homogenized annealed to eliminate segregation that may be formed during the casting process and promote uniform distribution of elements.

[0024] S2: The alloy ingot obtained after homogenization annealing in S1 is hot rolled or forged, and the high entropy effect is introduced through a thermomechanical deformation process to further improve the microstructural stability of the alloy; this process can optimize the texture and grain structure of the alloy by controlling the deformation temperature and deformation rate; the hot-treated alloy is then solution treated and aging treated after rapid cooling; the aging treatment further improves the hardness and tensile strength of the alloy through the strengthening effect of the precipitated phase; further processing and forming are then performed to obtain an ultra-high strength titanium alloy based on high entropy.

[0025] Example 1

[0026] S1: 50% titanium, 15% aluminum, 10% vanadium, 10% chromium, 15% zirconium and 5% molybdenum are mixed to obtain raw materials, and then the raw materials are placed in a vacuum induction furnace for smelting at a smelting temperature of 1600° C. During the smelting process, argon gas protection is used to perform rapid solidification casting to form a preliminary alloy ingot, and then the ingot is homogenized annealed at 1000° C. to obtain an alloy ingot after homogenization annealing;

[0027] S2: The alloy ingot after S1 homogenization annealing is hot rolled, and the high entropy effect is introduced through a thermomechanical deformation process, followed by a solid solution treatment at 950°C, an aging treatment after rapid cooling, and further extrusion forming to obtain an ultra-high strength titanium alloy based on high entropy.

[0028] Example 2

[0029] S1: 55% titanium, 15% aluminum, 15% vanadium, 5% chromium, 5% zirconium and 5% molybdenum are mixed to obtain raw materials, and then the raw materials are placed in a vacuum induction furnace for smelting at a smelting temperature of 1600° C. During the smelting process, argon gas protection is used to perform rapid solidification casting to form a preliminary alloy ingot, and then the ingot is homogenized annealed at 1000° C. to obtain an alloy ingot after homogenization annealing;

[0030] S2: The alloy ingot after S1 homogenization annealing is hot rolled, and the high entropy effect is introduced through a thermomechanical deformation process, followed by a solid solution treatment at 950°C, an aging treatment after rapid cooling, and further extrusion forming to obtain an ultra-high strength titanium alloy based on high entropy.

[0031] Example 3

[0032] S1: 50% titanium, 10% aluminum, 10% vanadium, 15% chromium, 5% zirconium and 10% molybdenum are mixed to obtain raw materials, and then the raw materials are placed in a vacuum induction furnace for smelting at a smelting temperature of 1600° C. During the smelting process, argon gas protection is used to perform rapid solidification casting to form a preliminary alloy ingot, and then the ingot is homogenized annealed at 1000° C. to obtain an alloy ingot after homogenization annealing;

[0033] S2: The alloy ingot after S1 homogenization annealing is hot rolled, and the high entropy effect is introduced through a thermomechanical deformation process, followed by a solid solution treatment at 950°C, an aging treatment after rapid cooling, and further extrusion forming to obtain an ultra-high strength titanium alloy based on high entropy.

[0034] The crystal structure of the embodiment was characterized, and the crystal structure of the alloy was analyzed by X-ray diffraction (XRD) and transmission electron microscopy (TEM) to confirm its single-phase solid solution characteristics and grain size and distribution; and mechanical property tests were performed on the prepared alloys to conduct tensile tests, compression tests and hardness tests to evaluate their tensile strength, yield strength, hardness and ductility; high-temperature performance tests were then performed: high-temperature tensile and creep tests were performed to evaluate the mechanical properties and stability of the alloy under high temperature conditions, especially its application performance above 600°C; finally, fatigue performance tests were performed, and low-cycle and high-cycle fatigue tests were performed on the material to evaluate its fatigue resistance. The test results show that the high entropy effect significantly improves the fatigue life of the material.

Claims

1. A method for preparing an ultra-high strength titanium alloy based on high entropy, characterized in that: The following steps are involved: S1: mixing high-purity titanium, aluminum, vanadium, chromium, zirconium and molybdenum to obtain raw materials, then smelting the raw materials, and then rapidly solidifying and casting to obtain alloy ingots, and homogenizing annealing the alloy ingots, and heat-insulating to obtain homogenizing annealed alloy ingots; S2: The homogenized annealed alloy ingot of S1 is subjected to thermomechanical processing to obtain a hot-processed alloy through thermomechanical deformation, and then subjected to solid solution treatment, cooling, and aging treatment to obtain an ultra-high strength titanium alloy based on high entropy.

2. The method for preparing an ultra-high strength titanium alloy based on high entropy according to claim 1, characterized in that: The titanium described in S1 accounts for 45% to 55%, the aluminum accounts for 5% to 15%, the vanadium accounts for 10% to 20%, the chromium accounts for 5% to 15%, the zirconium accounts for 5% to 10%, and the molybdenum accounts for 5% to 15%.

3. The method for preparing an ultra-high strength titanium alloy based on high entropy according to claim 1, characterized in that: The smelting temperature described in S1 is 1600°C, the holding time described is 60h, and the holding temperature is 1000°C.

4. The method for preparing an ultra-high strength titanium alloy based on high entropy according to claim 1, characterized in that: The annealing temperature described in S1 is 1000°C.

5. The method for preparing an ultra-high strength titanium alloy based on high entropy according to claim 1, characterized in that: The temperature of the solution treatment in S2 is 950°C.

6. The method for preparing an ultra-high strength titanium alloy based on high entropy according to claim 1, characterized in that: The thermomechanical processing described in S2 is any one of hot rolling and forging.

7. An ultra-high strength titanium alloy based on high entropy obtained according to the preparation method according to any one of claims 1 to 6.

8. The use of a high-entropy ultra-high strength titanium alloy according to claim 7, characterized in that: The high-entropy based ultra-high strength titanium alloy is used in the preparation of aviation engines, high-temperature structural parts, armor protection materials, and biological implants.