A pre-deformation heat treatment process for improving the strength of metastable β-titanium alloy

Abstract

The invention discloses a pre-deformation heat treatment process for improving the strength of a metastable β titanium alloy, and relates to the technical field of thermal processing and heat treatment of titanium alloy materials. Including: (1) Pre-heat treatment: heating the forged metastable β titanium alloy to T β The temperature above 0~100℃ is kept for 0.5~6h; (2) Pre-deformation: put the above metastable β titanium alloy at T β Below ~ 200℃ to T β Insulate above 100°C for 0.2-6h, and then perform rolling and thermal deformation; (3) Direct aging treatment: heat the above-mentioned metastable β-titanium alloy to 400-600°C, and hold for 4-12h. The invention can effectively control the precipitation of α phase in the microstructure of the alloy through the process of rolling thermal deformation and direct aging heat treatment, and fully recover the deformed structure, so that the metastable β titanium alloy can maintain its excellent plasticity. , greatly improving its strength and achieving a good match between strength and plasticity.

Description

technical field [0001] The invention discloses a pre-deformation heat treatment process for a metastable β titanium alloy, and relates to the technical field of thermal processing and heat treatment of titanium alloy materials. Background technique [0002] Metastable β titanium alloy has the characteristics of high specific strength, excellent formability, deep hardenability, etc., especially compared with α+β two-phase titanium alloy, its strength is higher, and it can reach more than 1200MPa after proper heat treatment , so it is more and more widely used in the aerospace field. [0003] The metastable β titanium alloy is a single β phase at high temperature, and the α phase will precipitate from the β matrix when it is cooled to the α+β two-phase region. The α phase is the main strengthening phase, and its size, morphology, distribution and volume fraction play an extremely important role in the mechanical properties of the metastable β titanium alloy. At present, the ...

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Problems solved by technology

However, it is difficult to control the mechanical properties of the metastable β-titanium alloy by combining the pre-deformation and heat treatment process. The pre-deformation parameters and the solution aging heat treatment process parameters will have a great impact on the final result. If the parameters are not selected properly, it will not be possible. Play a strengthening effect, and even deteriorate the performance of the alloy

For example, Zhang Hu et al. (Zhang Hu, Effect of heat treatment process on microstructure and properties of new high-strength β-titanium alloy, master’s dissertation, 2013) studied the pre-deformation direct aging heat treatment process of a new type of metastable β-titanium alloy, but due to The deformation amount of the pre-deformation is not enough, the β grains are not obviously elongated along the rolling direction, and they are approximately equiaxed, which makes the matrix defects less, resulting in the final pre-deformation and direct aging heat treatment. The strength of the alloy is not higher than that of the traditional solid. The strength of the alloy after solution aging heat treatment does not play a strengthening effect

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