CN-121992323-A - Ti-Mo series metastable beta titanium alloy plate with high plasticity and preparation method thereof

CN121992323ACN 121992323 ACN121992323 ACN 121992323ACN-121992323-A

Abstract

The invention discloses a Ti-Mo series metastable beta titanium alloy plate with high plasticity and a preparation method thereof, the method comprises the steps of firstly, performing four-fire hot forging on a Ti-12Mo alloy cast ingot obtained by three times of vacuum arc melting to obtain a forged plate blank; and fourthly, carrying out sand blasting, acid pickling and leveling on the annealed hot-rolled plate to obtain the high-plasticity metastable beta titanium alloy plate. According to the invention, through adjusting the temperature and the deformation of the forging process and optimizing the hot rolling temperature and the plate solution treatment system, omega brittle phase precipitation is effectively inhibited, the metastable beta phase is locked, the plastic phase transformation potential is introduced for subsequent deformation, and the high-plasticity titanium alloy plate with uniform thickness and good surface quality is obtained, can be punched, deep-drawn and bent into complex shapes, and meets the application requirements of different fields such as aerospace, electronic appliances and the like.

Inventors

YUAN LIHONG
WU JUNYU
CHEN JIAWEI
LI XINLIN
WANG GUODONG

Assignees

西北有色金属研究院

Dates

Publication Date: 20260508
Application Date: 20260228

Claims (10)

1. The preparation method of the Ti-Mo series metastable beta titanium alloy sheet is characterized by comprising the following steps: Step one, forging a plate blank, namely performing four-fire hot forging on a Ti-12Mo alloy cast ingot obtained by three times of vacuum arc melting to obtain a forged plate blank; Performing slab hot rolling, namely performing three-fire hot rolling on the forged slab obtained in the first step to obtain a hot rolled plate, wherein the temperature of the three-fire hot rolling is higher than the phase transition point temperature of the Ti-12Mo alloy, the heat preservation time t=h×k, wherein h is the thickness of the corresponding processed slab, the unit is mm, k is a time coefficient, the value of k is 0.8-1.5 min/mm, and the thickness of the hot rolled plate is 1.8-2.4 mm; Carrying out solution annealing, namely carrying out annealing treatment on the hot rolled plate obtained in the second step, wherein the annealing treatment temperature is 100 ℃ above the phase transition point temperature of the beta titanium alloy, the heat preservation time is 30-40 min, and the cooling mode is water cooling; And fourthly, sand blasting and acid washing, namely performing sand blasting, acid washing and leveling on the hot rolled plate subjected to the annealing treatment in the third step to obtain the high-plasticity metastable beta titanium alloy plate.
2. The preparation method of the Ti-Mo series metastable beta titanium alloy plate, which is characterized in that in the first step, the first hot forging heating temperature in the four hot forging is 1100-1150 ℃, the heat preservation time is 180-360 min, the first hot forging process and the second hot forging process are both two upsetting and two drawing processes, and the forging ratio of each upsetting or drawing is 1.8-2.0.
3. The method for producing a Ti-Mo-based metastable beta titanium alloy sheet according to claim 1, wherein the third hot forging process in the four hot forging is reverse three upsetting three drawing, each upsetting or drawing forging ratio is 1.8 to 2.0, and the fourth hot forging process is side drawing and drawing.
4. The preparation method of the Ti-Mo series metastable beta titanium alloy plate with high plasticity, which is disclosed in claim 1, wherein in the first step, the second fire forging heating temperature and the third fire forging heating temperature in the four-fire hot forging are 940 ℃ to 980 ℃, the fourth fire forging heating temperature is 940 ℃ to 960 ℃, the heat preservation time is 0.5 to 1 time of the diameter of the processed forging stock, the diameter unit is mm, the time unit is min, and the temperature of the processed forging stock is ensured to be higher than 850 ℃ through a furnace return in each fire hot forging process.
5. The preparation method of the Ti-Mo series metastable beta titanium alloy plate is characterized in that in the second step, the first hot rolling temperature and the second hot rolling temperature in the three hot rolling are 120-160 ℃ above the transformation point temperature of the Ti-12Mo alloy, the total deformation is 70-75%, the first hot rolling heat preservation time is 1-1.5 times of the thickness of a processed plate blank, the second hot rolling heat preservation time is 0.8-1.2 times of the thickness of the processed plate blank, the thickness unit is mm, the time unit is min, and the second hot rolling adopts reversing rolling.
6. The preparation method of the Ti-Mo series metastable beta titanium alloy plate with high plasticity, as claimed in claim 1, wherein in the second step, the third hot rolling direction in the three-hot rolling is consistent with the first hot rolling direction, the heating temperature is 120-160 ℃ above the transformation point temperature of the Ti-12Mo alloy, the heat preservation time is 0.8-1.2 times of the thickness of the processed plate blank, the thickness unit is mm, the time unit is min, and the total deformation of the third hot rolling is 70%.
7. The preparation method of the Ti-Mo series metastable beta titanium alloy plate with high plasticity, as claimed in claim 1, wherein in the fourth step, 80-mesh abrasive is adopted to uniformly sand the surface of the hot rolled plate, the single-sided treatment time is 30-60 s, the surface oxide layer is completely removed, and then 180-mesh abrasive is adopted to sand for 2 times, so that the surface roughness is reduced, and the treated surface is uniform silver gray.
8. The preparation method of the Ti-Mo series metastable beta titanium alloy plate, which is disclosed in claim 1, is characterized in that in the fourth step, the pickling is performed for 3-8 min by adopting a mixed solution consisting of 60% hydrofluoric acid, 40% nitric acid and water in a volume ratio of 1:6:18, and the pickling temperature is lower than 50 ℃.
9. The preparation method of the Ti-Mo series metastable beta titanium alloy plate, which is disclosed in claim 1, is characterized in that in the first step, the Ti-12Mo alloy cast ingot comprises the following components, by mass, from 11.98% to 12.06%, less than or equal to 0.25% Fe, less than or equal to 0.05% C, less than or equal to 0.05% N, less than or equal to 0.015% H, less than or equal to 0.15% O, and the balance Ti, wherein the phase transition point of the Ti-12Mo alloy is 795 ℃ to 805 ℃, the tensile strength of the metastable beta titanium alloy plate in the fourth step is 655MPa to 682MPa, the yield strength is 523MPa to 528 MPa, the elongation is 38% to 40.5%, and the alloy cast ingot has uniform thickness, no defects such as wave and warp, and has stable performance.
10. A Ti-Mo-based metastable beta titanium alloy sheet material characterized by being prepared by the method of any one of claims 1 to 9.

Description

Ti-Mo series metastable beta titanium alloy plate with high plasticity and preparation method thereof Technical Field The invention belongs to the technical field of nonferrous metal material processing, and particularly relates to a Ti-Mo series high-plasticity metastable beta titanium alloy plate and a preparation method thereof. Background The metastable beta titanium alloy has the outstanding advantages of low density, high specific strength, excellent corrosion resistance, good biocompatibility and the like, and has wide application prospect in the fields of aerospace, medical equipment, 3C electronics and the like. In terms of processability, metastable beta titanium alloys have good plasticity in solid solution and are suitable for cold forming, such as stamping and forging, so that it is more efficient to manufacture shells or parts of complex shape. Ti-12Mo is a high-performance metastable beta titanium alloy which is paid attention to in recent years, and a beta phase is stabilized by adding 12% of molybdenum element, so that a full beta phase structure can be obtained at room temperature, thereby having high plasticity and excellent cold forming potential, and the elongation percentage of the Ti-12Mo is superior to that of common metastable beta titanium alloys such as TB2, TB5 and the like. The Ti-12Mo alloy plate still faces significant challenges in the aspects of actual production forging and stable preparation of rolling forming, when the conventional forging process is adopted for forging at 100 ℃ above the transformation point, forging stock is cracked, the hot rolling technology is still immature, the problems of narrow process window, poor tissue uniformity and the like exist, and the tissue evolution rule in the rolling process and the influence mechanism of the tissue evolution rule on the final performance are not clear. Therefore, the systematic research on the forging and hot rolling process, microstructure evolution and the correlation with mechanical properties of the Ti-12Mo alloy plate preparation is of great significance in breaking through the technical bottlenecks of the material applied in the fields of aerospace, 3C electronics and the like and realizing the high-performance and stable preparation of the material. Disclosure of Invention The technical problem to be solved by the invention is to provide a preparation method of a Ti-Mo series metastable beta titanium alloy sheet with high plasticity aiming at the defects of the prior art. According to the method, four-hot forging, three-hot rolling and solution treatment are sequentially carried out on a Ti-12Mo alloy cast ingot, the temperature and the deformation of the forging process are regulated, the hot rolling temperature and the solution treatment system are optimized, omega brittle phase precipitation is effectively inhibited, alpha' martensitic phase and twin crystals are increased, the plastic deformation capacity of the material is improved, a metastable Ti-12Mo alloy plate with uniform thickness, good surface quality and excellent plasticity is obtained, and the technical problems of cold rolling cracking of the Ti-12Mo alloy plate and difficult production of a high-plasticity plate are solved. In order to solve the technical problems, the technical scheme adopted by the invention is that the preparation method of the Ti-Mo series high-plasticity metastable beta titanium alloy plate is characterized by comprising the following steps: Step one, forging a plate blank, namely performing four-fire hot forging on a Ti-12Mo alloy cast ingot obtained by three times of vacuum arc melting to obtain a forged plate blank; Performing slab hot rolling, namely performing three-fire hot rolling on the forged slab obtained in the first step to obtain a hot rolled plate, wherein the temperature of the three-fire hot rolling is higher than the phase transition point temperature of the Ti-12Mo alloy, the heat preservation time t=h×k, wherein h is the thickness of the corresponding processed slab, the unit is mm, k is a time coefficient, the value of k is 0.8-1.5 min/mm, and the thickness of the hot rolled plate is 1.8-2.4 mm; Carrying out solution annealing, namely carrying out annealing treatment on the hot rolled plate obtained in the second step, wherein the annealing treatment temperature is 100 ℃ above the phase transition point temperature of the beta titanium alloy, the heat preservation time is 30-40 min, and the cooling mode is water cooling; And fourthly, sand blasting and acid washing, namely performing sand blasting, acid washing and leveling on the hot rolled plate subjected to the annealing treatment in the third step to obtain the high-plasticity metastable beta titanium alloy plate. The preparation method of the Ti-Mo series metastable beta titanium alloy sheet is characterized in that the first fire forging heating temperature in the four-fire hot forging is 1100-1150 ℃, the heat preservation time is 180-360 min,