Damage Behaviour of Target Materials Caused by Subsonic to Hypervelocity Particle Impact

The aim of this paper is to investigate fundamental damage behaviour of metallic materials such as aluminum, carbon steel and titanium, which have typically different crystal structures, by the single impact from low velocity to hypervelocity. Impact tests by a WC ball were performed on the three metallic materials at various impact velocities and at normal angle. Both two-stage light gas gun and ordinary air gas gun were used in this study. Indentation shapes on a cross-sectional surface and the ratios of crater diameter and depth to the diameter of the WC ball were examined. Three modes were recognized in indentation configurations independent of the type of materials. Average contact pressure, which was obtained by the impact energy divided by indentation volume, showed not only a mechanical property of the target material during the impact process but also fracture strength of the projectile. A single particle impact test at a shallow impact angle and at a hypervelocity showed huge material removal even if its single impact and suggested the difference in mechanism of the material removal between subsonic and hypervelocity impacts.