In situ study of fracture behavior of ultrafine WC–Co cemented carbide

摘要

The fracture behavior of ultrafine WC–Co cemented carbide was demonstrated by in situ tensile tests in a transmission electron microscope. Using two kinds of cemented carbide samples with and without previously introduced microcracks, the process from deformation till fracture was studied. Particularly, the development and interaction of dislocations within Co and WC, as well as the alternation of dislocation motion between the two phases, was demonstrated, and the features of crack propagation in cemented carbide were disclosed. The finding of the dislocation characteristics and its correlation with the fracture behavior proposed the mechanisms of the ultrahigh fracture strength of the cemented carbide.