Investigation on fracture behavior of armor ceramics against HEAT penetration

In this study, the jet tip of high explosive anti tank (HEAT) within the ceramic target was trapped to investigate the interaction of the jet with the ceramic during HEAT penetration. Some trials, the introduction of a stand-off to regulate the jet amount without degrading the jet velocity and the adoption of the bonded specimen method, were devised for the HEAT firing test. These facilitated the examination of the internal damage induced in ceramic targets of 85% alumina (AD 85) and hot-pressed SiC (HS) in its impacted state. The fracture mechanisms of ceramic targets against HEAT penetration are discussed. The fracture behaviors of ceramic targets were of different shapes and the extent of the cracks depended upon the fracture and deformation behavior occurring ahead of the jet tip and around the penetration site. For AD 85 targets, the dynamic compaction of comminuted fine particles and powders occurred due to high pressure at the leading edge of the penetrating jet and around the penetrated regions. In the case of HS targets, however, high dense cracks occurred at the region ahead of the jet tip. Through fractographic observations of the damage zones on the contact surfaces, the fracture behavior of ceramic armors against jet penetration can be explained by the comminution zone model.