Plastic deformation of polycrystalline aluina introduced by scaled-down drop-weight impacts

We present our findings after scaled-down drop-weight tests, performed under relatively low loading conditions and employing a small-scale spherical indenter as a projectile, to boost the strain rate and energy density of the impact, resulted in the generation of a cavity of measurable depth on the surface of a pure, fully dense, alumina ceramic. We demonstrate that activated dislocations are a main contributor in the formation of the residual impression with an estimated maximum density of ~4.02×1014 m−2.