Dynamic Heterogeneous Response of Aluminum and Copper to Stress Waves

摘要

Holographic interferometry is used to measure the time- and space-resolved dynamic response of materials to stress waves. For free surface accelerations in the range - 10 exp 11 cm/sec exp 2 to 10 exp 10 cm/sec exp 2 and pressures less than 2 GPa we find that the grain structures of the polycrystalline metals aluminum and copper are correlated to the observed heterogeneous response. The response depends on the grain size, whether the material is being compressed or unloaded from a shock-compressed state and the rate of compression and decompression. Other factors, such as material strength, viscosity, and wave interactions, that may influence heterogeneous response are discussed. (ERA citation 08:046769)