Effect of 0.16 wt% hydrogen addition on high temperature deformation behavior of the Ti600 titanium alloy

Isothermal compression of the Ti600 titanium alloy at a hydrogen content of 0.16 wt% was carried out on a Gleeble-1500D thermal simulation machine at the deformation temperatures ranging from 800 °C to 960 °C and strain rates ranging from 0.001 s−1 to 10.0 s−1. The apparent activation energy for deformation of the Ti600 titanium alloy at a hydrogen content of 0.16 wt% is 629 kJ mol−1 in the α + β two-phase region. Processing map in isothermal compression of the Ti600 titanium alloy at a hydrogen content of 0.16 wt% has been constructed and compared with that of the as-received Ti600 titanium alloy. The superplastic deformation domain in the Ti600 titanium alloy at a hydrogen content of 0.16 wt% occurred at lower deformation temperature and higher strain rate, spread over a wider temperature range than that of the as-received Ti600 titanium alloy. A regime of flow instability at a deformation temperature lower than 840 °C and strain rate higher than 0.1 s−1 was also predicted for the Ti600 titanium alloy at a hydrogen content of 0.16 wt%.