Interaction of Indentation‐Induced Cracks on Single‐Crystal Silicon Carbide

Due to its transparency, high hardness, and low density, single‐crystal silicon carbide (SC‐SiC) is a candidate material for transparent armor and bullet‐proof windows. This manuscript explores the fracture anisotropy of the basal plane of two common HCP polytypes: 4H‐SiC and 6H‐SiC. Through single indentation, sequential indentation, and theoretical calculations, the primary and secondary cleavage directions are shown to be <11̄20> and <10̄10>, respectively. It is also shown that no appreciable tertiary cleavage direction exists on the basal plane. This investigation is the first to report how single‐crystal silicon carbide responds to multiple indentation. The results have fundamental value in modeling its fracture behavior.