Atomistic Investigation of Shock-Induced Amorphization within Micro-shear Bands in Hexagonal Close-Packed Titanium

The mechanical response of a single crystal titanium sample against (0001)_α surface impact was investigated using molecular dynamics simulation. Remarkably, non-uniform plastic deformation was observed in the sample. At high strain rates, amorphization occurred near the edge of the contact region where severe shear strain induced a large number of stacking faults (SFs) and dislocations. In contrast, the central part of the contact region underwent less deformation with significantly fewer dislocations. Moreover, instead of amorphization by consuming SFs and dislocations, there was a gradual increase in the density of dislocations and SFs during the process of amorphization. These local amorphous regions eventually grew into shear bands.