Mass Ejection from Free Surface of Shock-Loaded Metallic Plates

The mass ejection from free surfaces of aluminum alloy (Ly-12) and lead specimens under shock loading were measured using the piezelectric quartz crystal gauge technique. At shock pressure of 32 GPa, the ejected mass quantites of aluminum alloy with respec to the surface smooth finishes of 3.2 0.4 and 0.1 m are 1.53～3.28 g/m2, 0.2～0.3 g/m2 and 0.053～0.096 g/m2, respectively. At shock pressures of 13 and 47 GPa, the ejected mass quantites of lead with the surface smooth finish of 3.2 m are 26.4～42.4 g/m2 and 183～328 g/m2, respectively. Experiments also show that maximum shock pressure of about 20 GPa, the measured mass ejected under multiple shocks decreases remarkably in comparing with that under single shock. It is shown that the mass ejection is dependent on conditions of machining of free surface local melfing and the shock loading process.