On the influence of processing parameters on microstructural evolution of a near alpha titanium alloy

The effect of processing parameters on the microstructural evolution of Ti60 alloy were examined by isothermal compression tests over the temperature range of 960-1110°C at constant strain rates of 0.001-10s^-1. It was found that the flow stress decreased with increasing temperature and decreasing strain rate. The flow stress behavior revealed greater flow softening in the α+β phase field compared with that of β phase field. The volume fraction and grain size of primary α phase decreased and the prior-β grain size increased with increasing temperature. The lamellar α phase within the prior-β grains were distorted, broken up and globularized in the α+β phase field, while a small amount of recrystallized grains were formed at the elongated prior-β grain boundaries in the β phase field. The degree of dynamic recrystallization increased with increasing temperature, strain rate and strain. The recrystallized grain size increased with increasing temperature and decreasing strain rate.