Shock compaction response of Al₂O₃powders over range of initial density and high-pressure states

Recent studies into the shock response of granular Al₂O₃ have produced only a portion of the distended Hugoniot. The existing data shows distinct compaction curves for each initially distended state under shock compression, of which only initial states of 50% and 58% of theoretical maximum density (TMD) have been investigated. Additionally, these datasets contain a substantial gap in the peak pressure states, as granular Al₂O₃ has only been investigated up to 2.5 GPa. In this study, the effect of initial distention on the densification trends observed under shock compression is analyzed, including discussion on expected trends in the powder compaction curves of varying initial distended density states and extrapolating those trends to higher initial density states. Using this framework, a series of planar shock-compression experiments on Al₂O₃ powders over a range of initial density states, with peak pressure states in the 2-15 GPa regime, is proposed. These experiments, involving multi-probe PDV measurements of shock wave profiles, will be used to generate high-precision datasets for Al2O3 and will be correlated with other material systems to investigate the role of initial density and material strength on shock densification.