Shock equation of state of multi-constituent epoxy-metal particulate composites

The shock properties of epoxy-based particulate composites have been extensively studied in the literature. Generally, these materials only have a single particulate phase; typically alumina. This paper presents equation of state experiments conducted on five epoxy-based particulate composites. The shock stress and shock velocity states were measured for five different composites: two epoxy-aluminum two-phase composites, with various amounts of aluminum, and three epoxy-aluminum-(metal) composites, where the metal constituent was either copper, nickel, or tungsten. The impact velocities ranged from 300 to 960 m/s. Numerical simulations of the experiments of epoxy-Al are compared with mesoscale simulations of epoxy-Al(2)O(3) composites to investigate the effect of the soft versus hard particulate; additionally, an epoxy-Al-W simulation was conducted to investigate the material properties of the second phase on shock response of these materials. In these epoxy-based particulate composites, the slope of the shock velocity-particle velocity curve appears to depend on the epoxy binder. It is shown that the addition of only 10 vol% of a second, denser metallic phase significantly affects the shock response in these composites. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3531579]