CRATER FORMATION OF CARBON MATERIALS BY IMPACT OF A HIGH VELOCITY SPHERE

摘要

Four types of polycrystalline carbon material having nearly the same density are impacted by a 4 mm diameter ferrite sphere. Carbon specimens 40 mm long, with a 65 mm diameter, are impacted by the sphere traveling with an impact velocity of 600-1500 m/s. The size (depth, area and volume) of the induced crater is then measured. The relationship between the static properties of the materials and the crater size is investigated. In this impact velocity region, materials having larger effective fracture energies have smaller craters and vice versa. Crater size is also effected by Young's modulus and/or hardness of the materials. The crater area is related to the size of lateral cracks. Carbons having larger dissipation energies result in craters of smaller area and volume.