A numerical study of factors affecting the characterization of nanoindentation on silicon

In this paper, the responses of nanoindentation on bulk silicon were investigated using finite element analysis. A two-dimensional finite element model under the assumption of axisymmetry was successfully validated by the experimental load–displacement curve. Four factors: coefficient of friction, indentation depth, tip rounding and indenter geometry were investigated to characterize the induced responses of bulk silicon via load–displacement curve, indentation surface profile at the maximum loading depth, residual surface profile after unloading, plastic energy, elastic energy, Youngʹs modulus, hardness, and elastic recovery. Coefficients of friction were found to be insignificant, but the von Mises stress distributions after unloading between frictionless and frictional surfaces, indentation depth, tip rounding, and indenter geometry all showed having a distinct effect on stress, plastic energy, elastic energy, Youngʹs modulus, hardness, elastic recovery and surface profile. The degree of pile-up affecting the investigated factors is discussed as well.