The effect of WC, Mo 2C, TaC content on the microstructure and properties of ultra-fine TiC 0.7N 0.3 cermet

Abstract

The effect of Mo 2C, WC and TaC on the microstructure and properties of ultra-fine TiC 0.7N 0.3 cermet is studied. A series of cermets of varying nominal composition are prepared with ultra-fine powders, following normal powder metallurgical procedures. The results show that the addition of Mo 2C leads to the appearance of black cores in the ultra-fine cermet, which cannot be seen in medium particle cermet. However, excessive addition will result in the thickening of the rim, and the property goes down; the addition of WC makes the microstructure of TiC 0.7N 0.3–10 wt%Mo 2C–14.5%NiCo cermet more complex, and many white cores appear in it; excessive addition will be detrimental for the hardness and strength of the cermet, and in ultra-fine TiC 0.7N 0.3–14.5%NiCo cermet, the optimum addition level of Mo 2C, WC and TaC is 10, 15 and 7 wt%, respectively.