Determination of shock properties of ceramic corbit 98 : 98% alumina

Abstract

The shock properties of Bitossi Corbit 98 have been investigated. The Hugoniot Elastic Limit (HEL) was determined to be 7.96 ± 1.5 and 8.27 ± 0.8 GPa in two separate experiments. The strength in tension was found to be 0.271 GPa. The Hugoniot equation of state for elastic compression was calculated to be: Us=0.936*Up+10.53 This ceramic material-98% Al2O3-has been selected as the first component in a new layered armor design, which requires knowledge of the information discussed. The design encompasses an extremely hard first layer to deform the projectile, an orthotropic second layer to slow down the shock wave propagation, a third porous layer to absorb the shock wave energy through PV-work, and a fourth layer to provide confinement for the porous medium. Shock properties were determined by parallel plate impact experiments done at various velocities: 200-800m/s. The impactor material for asymmetric experiments was sapphire or aluminum. A single stage three inch bore gas gun was used to accelerate the projectile for experiments at NPS. Los Alamos National Lab used a higher performance gun to obtain higher impact speeds. A velocity interferometer was used to determine shock velocity in combination with time of arrival pins. These results confirmed previous work at higher pressures. Through this study, improved data for this ceramic were obtained, which will allow higher fidelity numeric simulations of overall armor system performance to be done.