Investigation of novel superhard materials by multi-cycling nanoindentation

Depth sensing nanoindentation is applied to characterize the mechanical properties of new superhard materials such as cubic c-BCx. Special load–time functions are developed to test the material by repeated loading and unloading processes. These intelligent load functions are applied in multi-cycling indents at the same place on the sample surface. Besides being time-efficient, the data collection method also does not suffer from lateral inhomogeneities of the sample. The hardness of the single phase cubic c-BCx sample was found to be 78 GPa and its indentation modulus is between 900 and 1000 GPa. Hysteresis loops are observed in the superhard material, which are attributed to the generation of nano-cracks.