Atomic behavior of single-crystal Ti nanowire plastic deformation under high strain rate simple tension

The molecular dynamic (MD) method is utilized to investigate the mechanical properties and deformation mechanism of [0001] and $$ \left[\overline{1}2\overline{1}0\right] $$ Ti nanowires at a high tensile strain rate. The simulation results reveal that the yield behavior of the [0001] Ti nanowire was dominated by a transition phase and led to like twinning deformation. The deformation twin led to a crystal rotation with a large angle. The $$ \left[\overline{1}2\overline{1}0\right] $$ Ti nanowires yielded through dislocation slip by a pyramidal plane of the HCP crystal structure. Therefore, the yield strength of the $$ \left[\overline{1}2\overline{1}0\right] $$ Ti nanowires was lower than that of the [0001] Ti nanowires. The broken strain of the $$ \left[\overline{1}2\overline{1}0\right] $$ Ti nanowire was also lower than that of the [0001] Ti nanowire. After yielding, the Ti nanowires plastically deformed through the slipping of an extended dislocation (a pair of partial dislocations), such that an FCC stacking fault was formed in the HCP crystal structure between the partial dislocations. Another extended dislocation in the FCC stacking fault was formed and moved by the slipping mechanism, causing further plastic deformation and reducing the flow stress.