Shock compression and spallation of palladium bicrystals with a Sigma 5 grain boundary

We investigate an elementary process of shock response of grain boundaries (GBs) using molecular dynamics simulations: shock compression and spallation in Pd bicrystals with a symmetric 5/(210)/100 GB. The loading direction is normal to GB. An elastic shock may induce the elastic-plastic or two-wave structure at the GB. The GB serves as a wave scattering center for the transverse motion perpendicular to the GB rotation axis and the shock direction: it induces a phase shift of 180, an increase in the amplitude of the particle velocity, GB sliding and grain orientation distortion. The GB is the preferred nucleation site both for dislocations and voids. Our results suggest that both microstructure and the loading geometry contribute to dynamic response of a solid.

Shock compression and spallation of palladium bicrystals with a Sigma 5 grain boundary Academic Article