A molecular dynamics study of nanoindentation of amorphous silicon carbide Available to Purchase

Through molecular dynamics simulation of nanoindentation of amorphous $a‐SiC$⁠, we have found a correlation between its atomic structure and the load-displacement $(P‐h)$ curve. We show that a density profile of $a‐SiC$ exhibits oscillations normal to the surface, analogous to liquid metal surfaces. Short-range $P‐h$ response of $a‐SiC$ is similar to that of crystalline $3C‐SiC$⁠, e.g., it shows a series of load drops associated with local rearrangements of atoms. However, the load drops are less pronounced than in $3C‐SiC$ due to lower critical stress required for rearrangement of local clusters of atoms. The nanoindentation damage is less localized than in $3C‐SiC$⁠. The maximum pressure under the indenter is 60% lower than in $3C‐SiC$ with the same system geometry. The onset of plastic deformation occurs at the depth of $0.5Å$⁠, which is $∼25%$ of the corresponding value in $3C‐SiC$⁠. $a‐SiC$ exhibits lower damping as compared to $3C‐SiC$⁠, which is reflected in the longer relaxation time of transient forces after each discrete indentation step.