The high temperature deformation behavior and microstructure of TC21 titanium alloy

TC21 titanium alloy was hot compressed isothermally at temperatures ranging from 880 °C to 950 °C and strain rates ranging from 0.01 to 10 s−1. Microstructures were investigated by electron backscatter diffraction (EBSD) technique and transmission electron microscopy (TEM), and processing maps were developed at different strains. It is found that strain rate is a key factor for the formation of hot deformation microstructure. The stress–strain curves were exhibited flow softening behavior at high strain rate above 1 s−1, while equiaxed grains were found at lower strain rates. There is no large instability zone besides two peak-areas of 880–900 °C, 1–10 s−1 and 925–950 °C, 10−0.5 to 10 s−1.