Microstructural evolution and toughening mechanism of WC-Co composite prepared by amorphous-crystallization method

In this study, toughening of WC-Co composite prepared by amorphous-crystallization method was investigated. Co-rich nanoparticles, a Co(W,C) solid solution, were incorporated into the WC matrix through the process integrating crystallization of amorphous Co2W4C powder and its in-situ reaction with carbon. The microstructural evolution of the ceramic-metal composite during fabrication was studied in detail. Owing to the interactions between Co-rich nanoparticles coherent with the WC matrix and the dislocations and stacking faults inside WC grains, the composite exhibited high hardness and strength combined with exceptional fracture toughness. The mechanisms for the synergistic improvement of mechanical properties of the composite were disclosed.