Transformation-induced plasticity in omega titanium

AH Zahiri and J Ombogo and TF Ma and P Chakraborty and L Cao, JOURNAL OF APPLIED PHYSICS, 129, 015105 (2021).

DOI: 10.1063/5.0035465

omega -titanium (Ti) is a high-pressure phase that is conventionally perceived to be brittle and nondeformable, although direct investigations of its deformation process remain scarce. In this work, we perform molecular dynamics simulations to study the deformation process of omega -Ti with initial defects and find that stress-induced omega -> alpha martensitic transformation can cause extensive plasticity in omega -Ti under various loading directions. Moreover, for the first time, we demonstrate that four types of transformation twins- 11 2 1 , 11 2 2 , 10 1 2 , and 10 1twins-can be formed through the omega -> alpha martensitic phase transformation. This work advances the understanding of plastic deformation in omega -Ti and unveils the essential role of the metastable omega -phase in the formation of transformation twins.