Constituent phase nanoindentation of WC/Co and Ti(C,N) hard metals

Nanoindentational experiments were carried out on WC/Co and Ti(C,N) hard metals with the aim of evaluating the feasibility of using the technique as a way of determining the mechanical properties of the constituent phases on a local scale. Clear differences were found between the load-displacement curves for the hard and soft binder phases in both materials. There were corresponding differences in the hardness of the two phases. However, the magnitude of the hardness and modulus values that were calculated were always much larger than those expected from macroscopic hardness tests, owing in part to the large effect on results of uncertainties in tip shape at the small indentation depths that had to be used to give information on a scale relevant to the microstructure of the samples. e WC/Co arrays of indentations were carried out to produce maps of hardness which could be clearly related to the details of the microstructure. With the Ti(C,N) cermet sample, the mapping was not successful, probably because of the complexity of the microstructure in these materials.