The Dynamic Strength Response of Alumina-Epoxy Formulations to Shock Loading

Matrix materials commonly occur in nature and engineered materials. When composed of diverse constituents, these materials can exhibit complex dynamic responses that often depend on the underlying mesoscale interactions of the matrix microstructure. Alumina-epoxy mixtures, referred to as ALOX, provide a ceramic-epoxy matrix whose shock Hugoniot has previously been characterized via plate impact experiments, but whose strength has been largely unexplored. In this study, the dynamic strength of ALOX was explored with a series of Richtmyer-Meshkov Instability experiments at the Dynamic Compression Sector at the Advanced Photon Source facility at Argonne National Laboratory. X-Ray Phase Contrast Imaging was used to record the shock response of the composite matrix, which in turn yielded the bulk material strength response. Mixtures of neat epoxy and ALOX containing 21.5% and 43.0% alumina by volume were tested. These data were then used in conjunction with numerical simulation to relate the particle-scale interactions to the bulk response of the composite matrix at high strain rates.