Microstructure and mechanical properties of 90WC-8Ni-2Mo2C cemented carbide developed by conventional powder metallurgy

Abstract

In this paper, the microstructure and mechanical properties of a WC-Ni based cemented carbide with the addition of 2wt% Mo2C, processed by conventional powder metallurgy, was investigated. With the addition of only Mo2C in the WC-Ni alloy system, the wettability between the WC and Ni binder phase was improved, which was confirmed by the increased density, hardness, fracture toughness and flexure strength of the cemented carbide obtained, which is superior than those observed in WC-10Ni cemented carbides and similar to those observed in WC-Co and WC-Ni-TiC-Mo2C cemented carbides. Microstructural examinations of the developed cemented carbide 90WC-8Ni-2Mo2C indicated that there was no excessive grain growth of the WC particles during sintering, confirming that Mo2C is a grain growth inhibitor as effective as other carbides such as VC, TiC, Cr2O3, showing that the addition of only Mo2C is able to improve the overall mechanical properties of the WC-Ni alloy system without sacrificing the toughness.