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

準安定型Ti合金における{332}113変形双晶の形成メカニズムに関する研究、応力誘起マルテンサイト相に注目

Cho, K.*; 森岡 亮太*; Harjo, S.   ; 川崎 卓郎   ; 安田 弘行*

Cho, K.*; Morioka, Ryota*; Harjo, S.; Kawasaki, Takuro; Yasuda, Hiroyuki*

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 martensite phase. We directly observed for the first time that the 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 martensite phase acts as a nucleation site for the {332}113 twins. Further increase in stress results in a replacement of the phase by the {332}113 twins.