Pressureless co-sintering behaviour of a steel/cemented carbide component: model bimaterial

Abstract

Abstract The co-sintering of model bimaterial {steel/cemented carbide} is studied. The cemented carbide consists of WC grain cemented by an Fe-rich binder. The steel is prepared from a powder mixture (Fe + WC + Cg). The experimental approach involves two steps: (1) the study of the single materials sintering (dimensional changes and weight losses during sintering, microstructure and hardness after sintering), (2) the study of the co-sintering of a two layer material which differs from the average behaviour of single materials. This difference arises from chemical interaction between the two materials such as M 6C formation in the interfacial region. M 6C formation is closely related to liquid formation in steel and liquid migration into the WC base material. A mechanism is proposed; it is based on WC dissolution and asymmetric diffusion of Wand C in the steel layer.