Effect of WC-Co granules on mechanical properties and microstructure of Ti(C,N)-based cermets

The effect of WC-Co granules addition on the microstructure and mechanical properties of TiC(nm)-TiN(nm)-Co-Mo-C cermets (shown as Ti(C,N)-based cermets in other part of the paper) was studied in this paper. The results show that the WC-Co granules distribute homogeneously in the matrix of Ti(C,N) based cermets. There was a transitional layer containing intermetallic compound between the WC-Co granules and the matrix of Ti(C,N) based cermets. Transverse rupture strength(TRS) and fracture toughness increase with the increase of WC-Co granules, reach a peak value at 15 vol% addition in comparing with that of without WC-Co granules addition. The toughening mechanisms were crack deflection, branching and trapping. However, when the content of WC-Co granules was higher than 15 vol%, the excessive content of WC-Co granules leaded to voids in the cermets, which decreased the mechanical properties of the cermets.