Vacuum superplastic deformation behavior of a near-alpha titanium alloy TA32

¹ Division of Titanium alloys, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016, China
² School of Materials Science and Engineering, University of Science and Technology of China, Hefei 230026, China
³ Beijing Electro-Mechanical Engineering Institute, Beijing 100074, China

Corresponding author: Zhiyong Chen, E-mail: zhiyongchen@imr.ac.cn

Abstract

TA32 is a heat-resistant titanium alloy developed for superplastic forming in fabrication of near-space supersonic aerocraft. Clarification of superplastic deformation behavior is important to the optimization of forming parameters. Superplastic tensile test was conducted in vacuum to eliminate the effect of surface oxidation on experimental data, the test temperature and strain rate varied from 900^oC to 960^oC and 5.32×10^-4 to 2.08×10^-2s^-1, respectively. It was observed that the size of equiaxed α grains exhibited a trend of coarsening with the increase of temperature and decrease of strain rate. Textures of deformed specimens exhibited random distribution with a decreased texture intensity compared with the as-received materials. The superplastic deformation mechanism of TA32 alloy was dominated by grain boundary sliding, which is accommodated by grain rotation and dynamic recrystallization.