Extremely toughened Ti-based solid-solution carbide cermets

A new cermet with extremely high toughness of similar to 22 MPa m(1/2) is designed. The high toughness of the cermet is mainly attributed to its characteristic microstructure, i.e., the even distribution of highly tough ceramic particles, unusual core/rim structure with a low internal strain, and strong bridging ligament. The microstructure and toughness of (Ti,W)C-Ni solid-solution cermets are strongly influenced by the addition of WC, i.e., by the W concentrations in the rim and binder phases. As the WC content increases, the shape of the carbide particles changes from faceted to rounded, and the toughness of the cermets increases sharply. In addition, crack propagation induced by an indentation is altered from the transgranular mode to the inter-granular mode when the WC content is increased. (C) 2019 Elsevier B.V. All rights reserved.