An investigation was conducted to examine the deformation and fracture behavior of single-crystal and sintered polycrystalline SiC surfaces exposed to cavitation. Cavitation erosion experiments were conducted in distilled water at 25°C using a magnetostrictive oscillator in close proximity (1 mm) to the surface of SiC. The horn frequency was 20 kHz, and the double amplitude of the vibrating disk was 50 μm. The results of the investigation indicate that the SiC {0001} surface could be deformed, in a plastic manner during cavitation. Dislocation etch pits ware formed when the surface was chemically etched. The number of defects, including dislocations in the SiC {0001} surface, increased with increasing exposure time to cavitation. The presence of intrinsic defects such as voids in the surficial layers of the sintered polycrystalline SiC determined the zones at which fractured grains and fracture pits (pores) were generated during cavitation. Single-crystal SiC had superior erosion resistance to that of sintered polycrystalline SiC.Presented at the 43rd Annual Meeting in Cleveland, Ohio May 9–12, 1988