Experimental study on crater configurations by hypervelocity impact with relation to their material properties of titanium alloys and aluminum alloys.

Hypervelocity-impact experiments were performed on the titanium alloys and aluminum alloys to study relation between the crater configurations and the static material properties. The copper projectiles were accelerated by means of a two-stage light-gas gun at averagely 2000m/sec, and were impacted on the zero oblique specimens. The crater configurations (crater depth, crater volume and mean crater diameter) were observed, and the relation to their static material properties (density, proof stress, elongation) were studied. As a result, several correlations between the deformation by the hypervelocity impact and the static material properties were found, as follows;(1) The crater depth of the both materials was dependent on their density and proof stress, and was expressed by the next equation.λ=37.8ρt-0.671σ0.2-0.175(2) The crater volume of the both materials decreased with an increase of the product of proof stress by elongation.(3) The aspect ratio of the crater of the both materials decreased with an increase of proof stress.(4) The crater configurations of the titanium alloys were different from these of the aluminum alloys. Decreasing the product of proof stress by elongation resulted in the increase of the mean crater diameter of the titanium alloys, whereas for the aluminum alloys, it resulted in the increase of the crater depth and the mean crater diameter, particularly the crater depth.