Pre-deformation heat treatment technology for improving strength of metastable beta titanium alloy

Abstract

The invention discloses a pre-deformation heat treatment technology for improving the strength of a metastable beta titanium alloy and relates to the technical field of heat processing and heat treatment of titanium alloy materials. The pre-deformation heat treatment technology comprises the following steps: (1) carrying out the heat treatment in advance: heating the forged-state metastable beta titanium alloy until the temperature is 0 to 100 DEG C higher than Tbeta and carrying out heat insulation for 0.5 to 6h; (2) pre-deforming: carrying out heat insulation on the metastable beta titaniumalloy for 0.2 to 6h at the temperature from the temperature the Tbeta or lower to 200 DEG C and at the temperature which is 0 to 100 DEG C higher than the Tbeta; then carrying out rolling and heat deformation; (3) carrying out direct ageing treatment: heating the metastable beta titanium alloy until the temperature is 400 to 600 DEG C and carrying out the heat insulation for 4 to 12h. According tothe pre-deformation heat treatment technology, the separation of an alpha phase in an alloy microstructure can be effectively regulated and controlled through rolling and heat deformation, and directageing treatment technologies, and a deformed structure is sufficiently recovered, so that the strength of the metastable beta titanium alloy is greatly improved under the condition that excellent plasticity of the metastable beta titanium alloy is kept; the strength and the plasticity are matched very well.

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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