Analysis of nanoindentation loading curves in SiC and SiO2 materials

On two SiC and a standard fused silica specimen, depth-sensing indentation tests with a Berkovich indenter were carried out at several peak loads. The loading part of the load-displacement curves were statistically analyzed and it was shown that the loading exponent of the relation P-h^n was lower than the expected value of 2 in most of the cases. Factors affecting the loading exponent have been considered and evaluated. It was demonstrated that their effect was minimal on the fitting results.