Variation of mechanical properties of WC-Co alloys with microstructure

KIc values of various grades of WC-Co alloys seem to correlate with the single microstructural parameter, thickness of the binder phase. The correlation holds well for cobalt-layer thicknesses ranging from 0.02 to 1.0 μm, which covers almost all commercial grades. The KIc values reported by some other researchers fit this curve just as well. Hence KIc may be predicted from the thickness of the binder phase in the final product, irrespective of grain size and cobalt content. The correlation between cobalt-layer thickness and hardness, however, is not unique, and there are different curves for different grain sizes or cobalt contents.