Characterization of Subsurface Damages of Static and Dynamic Indented ARMOR Ceramics: SiC and Si3N4

Static and dynamic indentation damage evolution was investigated in silicon carbide and nitride using sphere indentation and explosive indentation techniques. Different microstructures of SiC and Si 3 N 4 were prepared and the subsurface damage of the indented specimen was observed by using the bonded-interface technique. The results of static indentation shows that the microstructural heterogeneity determines the primary fracture mode of SiC and Si 3 N 4 : brittle fracture is dominant in fine-grained microstructure and quasi-plastic deformation in coarse-grained one. Dynamic indentation, however, generates massive quasi-plastic deformation zone in silicon carbide and silicon nitrides, except solid-state sintered SiC. Electron micrographs reveal that the major damage source of quasi-plastic zone is grain boundary defeat in both case of SiC and Si 3 N 4 .