LAUSR

Abstract Stacking fault tetrahedron (SFT) is a characteristic vacancy clustered defect which can cause deterioration of metals through plastic instability. Here, we have studied the effect of shock loading on the structural transformation of the SFT and subsequent damage production using molecular dynamics simulation. According to the investigation, at low shock intensity (0.2 km/s), the SFT collapses partially through inverse Silcox-Hirsch mechanism and re-evolve during the post shock recovery. With increasing the intensity of the shock (0.5 km/s), complete disruption of the tetrahedron structure occurs through dissociation of unfaulted Frank loop into perfect and partial dislocations causing plastic deformation. A threshold pressure value has been identified where the transformation transits from elastic to plastic collapse of SFT. At very high shock velocities (above 1.1 km/s), it is observed that amorphization and martensitic phase transition of the specimen occurs. However, the rarefaction wave generated from the presence of SFT has contributed towards the stabilization of the martensitic phase during shock wave propagation.