Dynamic globularization and restoration mechanism of Ti–5Al–2Sn–2Zr–4Mo–4Cr alloy during isothermal compression

Abstract

Dynamic globularization and restoration mechanism of Ti–5Al–2Sn–2Zr–4Mo–4Cr alloy during isothermal compression were investigated by employing a high-resolution electron backscatter diffraction technique (EBSD). Quantitative analysis was made in detail for further understanding the microstructure evolution. The results reveal that the dynamic globularization of primary α grains of Ti–5Al–2Sn–2Zr–4Mo–4Cr alloy is accomplished by the formation of high-angle boundaries (HABs) and the penetration of the β phase during isothermal compression, and an increase in deformation temperature leads to a more globular microstructure. The main restoration mechanism in the β phase of Ti–5Al–2Sn–2Zr–4Mo–4Cr alloy during isothermal compression is dynamic recovery (DRC) at a strain rate of 0.01s−1, while continuous dynamic recrystallization (CDRX) occurs as the strain rate increases to 1.0s−1/5.0s−1 and the α grains play an important role in recrystallization. The recrystallization in the β phase of Ti–5Al–2Sn–2Zr–4Mo–4Cr alloy during isothermal compression is promoted with the decreasing of deformation temperature and the increasing of strain rate. A strong 〈001〉 fiber texture develops where only DRC occurs and the deformation texture is weakened to a large extent after recrystallization of Ti–5Al–2Sn–2Zr–4Mo–4Cr alloy during isothermal compression.