Mechanical strength and fatigue lifetime of WC-Co cemented carbide in relation to the effectively loaded volume and surface

Abstract WC-Co hard metals are increasingly used in parts with more complex and highly fatigue loading situations. This requires a transition of material strength data provided by the manufacturer to the actual component. The method of the effectively loaded volume and surface has proven to work well for several static loading conditions and component sizes. This work provides evidence that this method can also be used with cyclic loading conditions. Specimen with three different effectively loaded volumes and surfaces have been exposed to monotonically increasing, as well as high cycle fatigue loads under four-point bending. The effectively loaded volumes and surfaces match the found characteristic fracture strengths as well as the logarithmic numbers of cycles to failure. A theoretical transition from the characteristic fracture strength to the fatigue limit across different geometries is demonstrated and matches the experimental data.