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

International audienceThe 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 M6C formation in the interfacial region. M6C 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 W and C in the steel layer