Surface degradation of cemented carbides in scratching contact with granite and diamond-The roles of microstructure and composition

In the present investigation, the initial micro-scale deformation and wear of polished cemented carbide surfaces is studied by micro scratching with diamond and granite styli, and also by instrumented micro and nanoindentation. The deformation and wear is evaluated on the sub-micrometer scale using high resolution FEG-SEM and FIB cross sectioning. The selected microstructures include besides four cemented carbide grades that are commonly used in rock drilling also binderless and Ni containing grades. This wider range of cemented carbides is used to gain fundamental insights into the relations between microstructure and micro-scale deformation and wear. The results are discussed with respect to their significance for wear of cemented carbides in rock drilling operations.