Atomistic processes during nanoindentation of amorphous silicon carbide

Atomistic mechanisms of nanoindentation of a-SiC have been studied by molecular dynamics simulations. The load displacement curve exhibits a series of load drops, reflecting the short-range topological order similar to crystalline 3C-SiC. In contrast to 3C-SiC, the load drops are irregularly spaced and less pronounced. The damage is spatially more extended than in 3C-SiC, and it exhibits long-range oscillations consistent with the indenter size. Hardness is similar to60% lower than in 3C-SiC and is in agreement with experiment. The onset of plastic deformation occurs at depth similar to75% lower than in 3C-SiC. (C) 2005 American Institute of Physics.