STUDY OF COMPRESSIVE STRENGTH OF SIC IN IMPACT EXPERIMENTS WITH DIVERGENT FLOW

Abstract

The axisymmetric divergent flow was generated in SiC samples by impact of convex copper flyer plates (radius of curvature ranging from 88 to 550 mm) having velocities from 550 to 700 m/s. The sample‐window (sapphire) interface velocities or the velocities of the free surface of the nickel witness plate were continuously monitored by VISAR. The maximum shear stress achieved under different confining stress just prior to the sample failure is associated with the compressive failure threshold of the SiC. Both the compressive failure threshold of SiC and the parameters of its inelastic deformation were found by matching the results of the AUTODYN‐2D numerical simulation with the experimentally obtained waveforms. The compressive failure threshold of SiC is characterized by a transition from brittle‐like behavior below the confining stress of 1.4–1.5 GPa to the ductile‐like one at higher confining stress.