Molecular Dynamics Simulations of Phase Transformation Behavior at BCC-HCP Interfaces in Titanium

Phase transformation behaviors at interfaces between BCC and HCP in pure titanium were investigated using molecular dynamics simulations. This study focused on the influences of orientation relationships on the BCC-to-HCP phase transformation. For the Mao orientation relationship, planar migration of the BCC-HCP interface was observed, and the interface migration velocity decreased with increasing temperature. On the other hand, for the Burgers orientation relationship, which differs from the Mao orientation relationship by a rotation of 5.26° about the 110BCC axis, growth with protrusions was observed instead of planar migration of the interface. Additionally, the (̅1010)HCP//(121̅)BCC interface which bounded the protruding growth regions, did not sustain stable migration. These molecular dynamics simulations demonstrate that orientation relationships at the BCC-HCP interfaces strongly affect the phase transformation behavior.