Atomistic simulations of shock-induced microjet from a grooved aluminium surface

Molecular dynamics simulations have been used to study the microjet from a grooved aluminium surface under shock loading. Plastic deformation and release melting during microjetting are both presented by the centrosymmetry parameter, where the effect of release melting is discussed in detail. Consequently, we obtain the change law of microjet morphology and mass with the shock strength. The microjet mass is found to keep a linear increase with the post-shock particle velocity prior to release melting, and the release melting can evidently enhance the microjet. However, while the release melting speed is fast, the microjet mass shows a linear increase again, because the material strength can already be neglected. Also, our simulations suggest that the head speed of microjet always keeps a linear increase with the post-shock particle velocity, nearly independent of melting. Finally, the mechanical evolution of microjet matter with time is also discussed.