Study on formation mechanism of {332}< 113 > deformation twinning in metastable beta-type Ti alloy focusing on stress-induced alpha '' martensite phase

摘要

Deformation behavior of Ti-12Mo alloy which is primarily deformed by {332)<113> deformation twinning was studied by in situ neutron diffraction measurements and deformation structure analyses, focusing on the formation of stress-induced alpha '' martensite phase. We directly observed for the first time that the alpha '' phase was formed at the initial stage of the plastic deformation and the volume fraction of the phase increased with increasing plastic deformation. This stress-induced alpha '' martensite phase acts as a nucleation site for the {332}<113> twins. Further increase in stress results in a replacement of the alpha '' phase by the {332}<113> twins. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.