A study of crater volumes produced by single particles at low impact velocities

Targets of lead, aluminium, cold-worked copper, 60-40 brass and steel were struck by steel spheres of various masses at low velocities in the range 6–10 m s^?1. Impacts were both normal and oblique. The crater volumes were calculated and in some cases evaluated by using plasticine. Crater volumes do not indicate wear. However, microscopic observations show severe radial deformation of a narrow zone of the target around the crater. The striking spheres skid as they escape. Splinters of very small amounts of metal are removed from the crater during the first strike. Surface melting appears to take place even at such low velocities.