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

In this work, the hot compression behavior at 600 degrees C of a metastable beta 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 anda final soft ening stage. For the near linear hardening stage, the alpha precipitates are formed on the grain boundaries (alpha GB). The hardening behavior of the alloy in this stage balanced by boundary hardening through the formation of alpha GB. For the discontinuous yielding stage, the softening of deformation behavior is originated from the fragmentation of the alpha GB and the generation and movement of mobile dislocation. For the hardening stage follow the discontinuous yielding, the massive beta to alpha 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 alpha phase and the dislocation slips contribute to the softening behavior. The present results provide comprehensive information on hot deformation mechanisms of metastable beta titanium alloys. (c) 2020 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).