Indentation fatigue of WC grains in WC–Co composite

Indentation fatigue of WC grains on basal and prismatic planes in WC–Co cemented carbide has been investigated using instrumented indentation at nano level and applied loads from 5 mN to 50 mN. The influence of indentation load and crystallographic orientation of WC grains has been studied. Scanning electron microscopy (SEM), electron backscattered diffraction (EBSD) and atomic force microscopy (AFM) have been used for the characterization of microstructure, orientation of WC grains, topography of indents and slip lines in WC grains. Significant influence of the crystallographic orientation of WC grains on the indentation fatigue has been found. The indentation depth increased with the increasing load more intensively during the fatigue test of the prismatic planes than the basal planes. This behavior is probably connected with the different slip and dislocation mechanisms during the indentation of basal and prismatic planes.