The interplay relationship between phase transformation and deformation behavior during hot compression in a metastable β titanium alloy

Abstract

In this work, the hot compression behavior at 600 °C of a metastable β titanium alloy is investigated to resolve the correlation between phase transformation and deformation behavior. It is demonstrated that the deformation behavior includes a near linear hardening stage, a discontinuous yielding stage, a hardening stage and a final softening stage. For the near linear hardening stage, the α precipitates are formed on the grain boundaries (αGB). The hardening behavior of the alloy in this stage balanced by boundary hardening through the formation of αGB. For the discontinuous yielding stage, the softening of deformation behavior is originated from the fragmentation of the αGB and the generation and movement of mobile dislocation. For the hardening stage follow the discontinuous yielding, the massive β to α phase transformation were occurred and mainly contributed to the hardening behavior. For the final softening behavior stage, three activities: the formation of deformation bands, the spheroidization of α phase and the dislocation slips contribute to the softening behavior. The present results provide comprehensive information on hot deformation mechanisms of metastable β titanium alloys.