Enhanced ballistic performance of confined multi-layered ceramic targets against long rod penetrators through interface defeat

Impact recovery experiments on confined multi-layered ceramic targets are performed to identify materials and structural design issues in interface defeat of long rod tungsten heavy alloy (WHA) penetrators. In-situ stress measurements are made, with embedded manganin/constantan gauges, and velocity histories of the target rear surface are measured using an interferometric technique. Material response to penetration is examined by considering different hardness of the cover steel plate and two types of ceramics, viz., Alumina and TiB₂. The combined material-structural response is examined by changing the thickness of the graphite plate, used to accommodate the deforming WHA penetrator, and by welding top and bottom plates with the middle plate to increase the stiffness of the assembled multi-layered target. In total, eight shots are performed in the velocity range of 1.5-1.7 km/s. Ceramic damage is studied by quantifying the size and distribution of fragments in recovered sample. SEM and optical microscopy performed on recovered ceramic plates show that microcracking is the dominant failure mode in multi-layered ceramic targets. Crack surface area per unit volume is estimated, on cross sections of the ceramic targets along several orientations. Correlation between axial stress and crack density is investigated. Examination of the post-shot multi-layered ceramic targets revealed complete and partial interface defeat of long rod tungsten heavy alloy penetrators. Targets with extra stiffness, on account of weld and larger bottom plate thickness, achieved complete defeat of the penetrator.