Dependence of microscale abrasion mechanisms of WC-Co hardmetals on abrasive type

The silicon carbide and alumina abrasives primarily caused wear by preferential removal of the binder phase followed by pullout of the WC particles. As expected, with a given WC grain size in the hardmetal, the wear rate increased as the binder volume fraction increased. However, with a fixed binder phase volume fraction, the wear rate increased as the WC grain size in the hardmetal decreased (i.e. as hardness increased). Behaviour with the diamond abrasive was very different, and apparently not dominated by binder phase removal and carbide pullout. Here, the wear rates of all the cermets examined were similar and may be explained following the model of Engqvist and Axén (Tribology Int., 32 (1999) 527-534).