Structure and properties of binder phases in cemented carbides

Major properties and structures of Co-based, Ni-based, and Fe-based binders of cemented carbides are presented. Vertical sections of the calculated W–C–(Fe, Co, and Ni) phase diagrams through the carbon angle at a binder content of 20 wt.% are reported, compared, and analyzed. Unique properties of Co-based binders, in particular, their increased work-hardening rates due to the fcc-hcp martensitic transformation occurring as a result of fatigue are described. The results of experiments on the cobalt binder dispersion hardening in WC–Co cemented carbides due to their annealing are reported. Processes of the formation of nanoparticles consisting of different W–Co–C phases in the binder phase of cemented carbides are outlined. Advantages and disadvantages of alternative binders of the Co–Fe–Ni system are described and analyzed.