Grinding of WC-Co Cemented Carbides

Abstract

An investigation is reported on the grinding process for WC-Co cemented carbides with diamond wheels. SEM examination of the grinding detritus revealed that material removal occurs mainly by flow-type chip formation. A grinding model is proposed whereby the total grinding energy is partitioned into a chip formation component for material removal, and a plowing component causing plastic deformation of the workpiece by a force along the engaged cutting edges. With many wheel-workpiece combinations, the specific chip formation energy was found to be comparable to the dissociation energy of WC, suggesting chip formation by constrained adiabatic plastic flow to the energy limit. Wheel topography measurements showed an increasing number of cutting points with coarser grit size, which is attributed to coarser grains having more cutting points per grain and less of a tendency to dislodge. Finished surfaces exhibited grooves along the grinding direction with valleys depleted of cobalt and ridges along the sides of the grooves rich in cobalt.