Processing method of fine-grain superplastic TA15 titanium alloy sheet

Abstract

The invention provides a processing method of a fine-grain superplastic TA15 titanium alloy sheet. The processing method includes steps of firstly, heating a TA15 titanium alloy sheet blank; secondly, performing first rolling to obtain first semi-finished sheet blanks; thirdly, heating the first semi-finished sheet blanks; fourthly, performing second rolling to obtain second semi-finished sheet blanks; fifthly, manufacturing several second semi-finished sheet blanks into a ply rolling pack; sixthly, heating the ply rolling pack; seventhly, performing third rolling and annealing, performing alkaline washing, acid pickling, sanding and shearing after unpacking, and obtaining a fine-grain superplastic TA15 titanium alloy sheet. The fine-grain superplastic TA15 titanium alloy sheet processed by the processing method is uniform in texture, fine in grains and excellent in superplasticity and consistence of performance, and has excellent process controllability and stability in batch production.

Description

technical field [0001] The invention belongs to the technical field of titanium alloy material processing, and in particular relates to a processing method for a fine-grained superplastic TA15 titanium alloy thin plate. Background technique [0002] Because of its high superplasticity, fine-grained titanium alloy can be processed into thin-walled structural parts by superplastic forming, and can widely replace various precision castings and forgings of aircraft. To the obvious weight reduction effect, greatly increase the payload. This type of component generally has the characteristics of high rib and thin belly, complex shape, and large projected area, which requires high tissue performance. [0003] TA15 titanium alloy has good comprehensive mechanical properties, and its strength, fracture toughness, fatigue limit, and stress corrosion resistance are slightly higher than TC4 titanium alloy. Important structural parts with high height and complex stress have been widely...

AI Technical Summary

Problems solved by technology

However, due to the characteristics of high strength, poor plasticity, and small cold rolling deformation of TA15 titanium alloy, the production of thin plates is difficult, especially the grain size and flatness of the plates are difficult to control, and the anisotropy control level is poor, resulting in TA15 The quality of titanium alloy sheets is unstable, the yield is low, and the superplasticity is not high, which limits the application of TA15 titanium alloy sheets in high-end fields

[0004] The traditional TA15 titanium alloy thin plate processing technology usually adopts unidirectional rolling. The direction of the plate does not change during the rolling process, and the grains deform along one direction during the rolling process, resulting in large differences in the transverse and longitudinal microstructures. The processing flow line is obvious, and the surface of the plate will produce "corduroy groove" along the rolling direction

In addition, the traditional process generally uses a combination of "hot rolling + cold rolling" to process fine-grained superplastic TA15 titanium alloy plates. Due to the obvious work hardening of cold rolling deformation, subsequent heat treatment is difficult to eliminate this effect, resulting in low plasticity of the plate; Moreover, due to the small amount of cold rolling deformation, the amount of thinning per pass is small, the rolling process is large, and the processing cost is high

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