Impact of metallic projectiles on ceramic targets: transition between interface defeat and penetration

Armour systems capable of defeating an incoming projectile on the surface of a ceramic have been reported by several authors. This capability, called interface defeat, signifies that the projectile material is forced to flow radially outwards on the surface of the ceramic without penetrating significantly. In order to investigate the conditions for interface defeat, two models for the interaction of a metallic projectile and a ceramic target were established. With the aid of them, upper and lower bounds for the transition impact velocity between interface defeat and normal penetration were estimated for a given combination of metallic projectile and ceramic target. These approximate bounds were found to be consistent with transition velocities determined experimentally for two projectile materials (tungsten and molybdenum) and five target materials (two types of silicon carbide, boron carbide, titanium diboride and a polycrystalline diamond composite).