Direct hcp→bcc structural phase transition observed in titanium alloy at high pressure

Structural stability of Ti alloy, stabilized as a mixture of bcc (β) and hcp (α) phases, was investigated up to 71GPa. Over this pressure, β phase remains stable, while for α phase, a decrease in c∕a ratio from 1.601 at ambient pressure to 1.568 at 36GPa is observed, followed by an increase to 1.613 at 44GPa. A steady value is then observed up to 67GPa. Above 58GPa, the authors also observe that α phase peak intensity is decreasing. At 67GPa, the authors only observe β phase peaks, which indicates that α→β structural phase transition is complete.