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CN-122012985-A - Mo-containing high-strength high-plasticity Ti-6Al-4V alloy and preparation method thereof

CN122012985ACN 122012985 ACN122012985 ACN 122012985ACN-122012985-A

Abstract

The invention belongs to the field of preparation and processing of titanium alloy materials, and particularly relates to a Mo-containing high-strength high-plasticity Ti-6Al-4V alloy and a preparation method thereof, wherein the Mo-containing high-strength high-plasticity Ti-6Al-4V alloy comprises, by weight, 1.0% -3.5% of Mo, 5.50% -6.75% of Al, 3.5% -4.5% of V, fe less than or equal to 0.3%, O less than or equal to 0.2% of O, and the balance of Ti and unavoidable impurities. According to the technical scheme disclosed by the invention, the Ti-6Al-4V alloy with high strength and high plasticity is obtained by adding alloy element Mo and a hot rolling annealing process. The process is simple and convenient to operate, is easy to popularize and apply in actual production, and the alpha phase and beta transformation structure is obtained through annealing treatment, the structure is uniform, the yield strength of the prepared Mo-containing high-strength high-plasticity Ti-6Al-V alloy is more than or equal to 997.5MPa, the tensile strength is more than or equal to 1092.4MPa, and the elongation is more than or equal to 13.3%.

Inventors

  • Huang Zhaokuo
  • KANG QIANG
  • WANG JIALE
  • MA ZHIWEI
  • YAN HUI
  • XU PEI
  • TENG AIJUN
  • GUO JIE
  • Dong Entao
  • GAO QIANG
  • ZHANG ZHAO
  • YUAN ZIKAI
  • WANG PENG
  • LI WENMO

Assignees

  • 鞍钢集团北京研究院有限公司

Dates

Publication Date
20260512
Application Date
20260226

Claims (7)

  1. 1. A high-strength high-plasticity Ti-6Al-4V alloy containing Mo is characterized by comprising the following chemical components, by weight, 1.0% -3.5% of Mo, 5.50% -6.75% of Al, 3.5% -4.5% of V, less than or equal to 0.3% of Fe, less than or equal to 0.2% of O, and the balance of Ti and unavoidable impurities.
  2. 2. The Mo-containing high-strength high-plasticity Ti-6Al-4V alloy according to claim 1, wherein the microstructure of the Ti-6Al-4V alloy is composed of an α phase and a β transition structure, and the microstructure is relatively uniform, wherein the α phase accounts for 22.7% -35.2%, the β transition structure accounts for 64.8% -77.3%, and the total area accounts for 100%.
  3. 3. The Mo-containing high-strength high-plasticity Ti-6Al-4V alloy according to claim 1, wherein said Ti-6Al-4V alloy has a yield strength of 997.5MPa or more, a tensile strength of 1092.4MPa or more, and an elongation of 13.3% or more.
  4. 4. The method for preparing the Mo-containing high-strength high-plasticity Ti-6Al-4V alloy according to any one of claims 1 to 3, which is characterized by comprising the following steps of vacuum melting, hot rolling and annealing; Vacuum smelting, namely smelting arc current of 400-450A at the vacuum degree of 0.05-0.10 MPa for 4-6 min, smelting cast ingots for 3-5 times/each cast ingot, and carrying out suction casting by adopting a copper die to obtain square cast ingots; hot rolling, namely heating to 930-980 ℃ and keeping the temperature for 0.5-2.0 h, and discharging from a furnace to immediately roll after reaching the temperature to obtain the alloy after hot rolling; annealing, namely annealing the alloy after hot rolling, wherein the annealing temperature is 780-830 ℃, the heat preservation time is 20-60 min, and the alloy is cooled to room temperature in a natural cooling mode to obtain the Ti-6Al-4V alloy.
  5. 5. The method according to claim 4, wherein the alloy material comprises, by weight, 100% of Mo 1.0% -3.5%, al 5.50% -6.75%, V3.5% -4.5%, fe less than or equal to 0.3%, O less than or equal to 0.2%, and the balance of Ti or unavoidable impurities.
  6. 6. The method according to claim 4, wherein the vacuum melting is carried out by charging alloy raw material into a vacuum non-consumable electric arc furnace, vacuumizing the furnace until the vacuum degree reaches 1.0X10 -3 Pa, closing the vacuum gauge, charging argon gas until the vacuum degree reaches 0.05MPa, and starting melting.
  7. 7. The method according to claim 4, wherein the hot rolling is performed by heating the square ingot in a resistance furnace, and the deformation amount of the alloy after hot rolling is 80% -90%.

Description

Mo-containing high-strength high-plasticity Ti-6Al-4V alloy and preparation method thereof Technical Field The invention belongs to the technical field of preparation and processing of titanium alloy materials, and particularly relates to a Mo-containing high-strength high-plasticity Ti-6Al-4V alloy and a preparation method thereof. Background Titanium and titanium alloy have been widely used in the fields of aerospace, medical chemistry, military national defense, ocean engineering and the like due to excellent comprehensive properties such as high strength, low density, good corrosion resistance and the like. With the development of science and technology, titanium alloy is a preferred material in many fields, so that the requirements of titanium alloy in many fields are increasing, and the engineering design requirements are more strict. Titanium alloy materials with better research and development comprehensive properties become an important direction for researching and developing titanium alloys. Titanium aluminum vanadium based alloys are a class of titanium alloys currently used in very large amounts, with the typical designation Ti-6Al-4V (TC 4) alloy. The room-temperature tensile strength of the conventional Ti-6Al-4V is about 900-1000 MPa, and the elongation is about 10-12%. Some application scenes with higher requirements, such as aviation structural parts, need to bear higher loads, titanium alloy is required to have high strength and good plasticity, the comprehensive performance of conventional Ti-6Al-4V needs to be further improved to adapt to stricter application scenes, and research and development of the high-strength high-plasticity Ti-6Al-4V alloy is of great significance in meeting the requirements of multiple fields on high-performance titanium alloy and expanding the application range of the titanium alloy continuously. CN106399886A discloses a TC4 fine-grain titanium alloy sheet and a preparation method thereof, wherein the elongation after fracture of the TC4 alloy is better than 15-19%, the tensile strength is 1020-1050 MPa, but the hot working process is complex, the hot working process relates to slab cladding treatment, the production of rolling of a lap rolling bag and the like, the production efficiency is general, and the production cost is higher. CN117403100A discloses a high-performance short-flow TC4 titanium alloy thin strip and a preparation method thereof, the method prepares and processes the TC4 titanium alloy thin strip on line by hydraulic tension and warm rolling, the tensile strength of the obtained TC4 titanium alloy thin strip is 1241 MPa-1406 MPa, the total elongation is 5.0% -9.2%, the strength performance is higher, the elongation is lower, and the rolling process is more complex. The invention aims to provide a Mo-containing high-strength high-plasticity Ti-6Al-4V alloy, which realizes the technical scheme that the room temperature tensile strength is improved by 10-15% and the extensibility is improved by 10% on the premise of keeping a hot working process simple and easy to operate, and solves the problem that the traditional Ti-6Al-4V alloy is difficult to achieve both high strength and high plasticity. Disclosure of Invention In order to overcome the defects of the prior art, the invention aims to provide the Ti-6Al-4V alloy containing Mo and high in strength and high in plasticity and the preparation method thereof, and the Ti-6Al-4V alloy has the advantages of high strength and high plasticity by adding alloy elements and hot rolling annealing process, and the process is simple and convenient to operate. According to one aspect of the invention, the high-strength high-plasticity Ti-6Al-4V alloy containing Mo comprises the following chemical components, by weight, 1.0% -3.5% of Mo, 5.50% -6.75% of Al, 3.5% -4.5% of V, less than or equal to 0.3% of Fe, less than or equal to 0.2% of O, and the balance of Ti and unavoidable impurities. The alloy of the invention is designed for the following reasons: Mo is a strong beta stable element, forms strong lattice distortion in beta phase, greatly improves the strength of beta phase, effectively dissolves in alpha phase, and can play a role in strengthening. The strong alpha stable element forms solid solution strengthening through forming a substitutional solid solution, and the proper amount of the Al element can improve the room temperature and high temperature strength performance of the titanium alloy. When the Al content is low, the alpha phase stability is insufficient, and the room temperature strength is lowered. When the Al content is high, a brittle Ti 3 Al phase is easily precipitated, resulting in embrittlement of the alloy. The weak beta stable element can be infinitely dissolved in a beta phase region to strengthen the beta phase, and meanwhile, the toughness of the beta phase is reserved. Can effectively inhibit the precipitation of brittle Ti 3 Al phase caused by Al. When the V content is low, t