Ejecta production from metal Sn into inert gases

Abstract

Ejecta is produced from the shock-loaded perturbed surface of metals and subsequently breaks into small particles that are an important source of micro-particles/gas mixing during ejecta's transport and conversion. In engineering applications, the surrounding gas is often neglected during ejecta's formation, and many source models have been established based on the vacuum condition. However, the formation of the spike is always accompanied by gas, which has an important effect on the ejecta's mass/velocity distribution and the transformation time for a steady-state shock wave. To study the interaction between ejecta and ambient gases, we explore the ejecta production at the sinusoidal interface in the presence of argon gas. Six values of gas pressure and five interfaces were chosen to study the formation of the spike/micro-jet by using multi-component elastic–plastic hydro-dynamic codes. The results show that gas perturbed by the spike generated a precursory bow-shaped shock and gradually transformed into a plane wave. The transformation time was related to the velocity of the spike tip and the transmitted wave. The total mass of ejecta in gas had no distinct difference with that in vacuum, while it was significantly increased at the jet tip, which indicates that gas resistance reduced the spike velocity but did not influence the bubble. The initial velocity of the spike was insensitive to gas pressure but its decaying rate was positively correlated with gas pressure. As kh0 increased, the initial velocity of the spike tip and its decaying range increased, making it difficult to attain a steady state.