Mechanism of α → β dynamic transformation in commercial pure titanium deformed at high temperature below β-transus

Abstract

A counterintuitive strain-induced α → β dynamic transformation of commercial pure titanium deformed at a temperature below the β-transus was investigated. It was revealed that the serrated-shaped β phase first formed at grain boundaries and then grew into α grains. Finally, the initial equiaxed α grain was transformed into a (α + β) lamellar structure. The development of β phase laths was controlled by moving dislocations in the α phase, and both were affected by the diffusion of β-stabilizing elements. Furthermore, the redistribution of Fe in CP-Ti resulted in a special reversal transformation of β → α in the isothermal holding period after deformation.