Effect of Electrical Discharge Machining on strength and reliability of WC–30%Co composite

Tungsten carbide/Cobalt (WC–Co) composite is one of the important composite materials, which is used for manufacturing of cutting tools, dies and other special tools. It has very high hardness and excellent resistance to shock and wear. It is not possible to machine this material easily with conventional machining techniques. Due to the good electrical conductivity of WC–Co, it is usually machined by Electrical Discharge Machining (EDM). EDM process often results in the surface damage of bulk WC–Co, and the influence of the damage would affect the reliability. It is important to investigate the effect of electric discharge machining process on the properties of WC–Co cemented carbides before applying its engineering application. For these composites, maintenance of proper fracture strength is an important concern and is to be controlled. In this work, an attempt has been made to investigate the fracture strength and the reliability of EDMed WC–Co composite using the Weibull distribution analysis. The comparison of results between the machined composites and un-machined composites is carried out and presented in this study.