SHEAR LOCALIZATION AND COMMINUTION OF GRANULAR AND FRAGMENTED SILICON-CARBIDE

Granular and pre-fractured bulk silicon carbide were subjected to high strain, high-strain-rate deformation by radial symmetric collapse of a thick-wall cylinder. Profuse shear-band formation was observed, indi cating the deformation had inhomogeneous characteristics. The granular silicon carbide had lower shear-band displacement, spacing between sh ear bands and thickness of shear bands than the pre-fractured silicon carbide. Bimodal particle size distribution was seen inside the shear bands for both materials. The shear localization in the granular silic on carbide was primarily due to particle break-up (comminution) and re arrangement of the comminuted particles. The shear bands in the pre-Fr actured silicon carbide were formed through the incorporation of fragm ents from the shear-band interfaces and the erosion of fragments insid e the shear band.