On the composition of Fe-Ni-Co-WC-based cemented carbides

The alternative binder metals to cobalt in cemented carbides, iron and nickel, are today utilised to a minor extent only. This is largely due to the excellent properties offered by cobalt and in particular when it is used in combination with tungsten carbide, WC. However, the difficulties involved when selecting the composition of the binder metal and in particular of the carbon content of the alloy, when other metals than cobalt are involved, might have influenced the development process. The knowledge of the constitution of the systems of importance for cemented carbides, based upon these elements, has increased during the past 10-15 years. New computational tools for the description of higher-order systems have also increased the possibilities of overcoming many of the problems encountered when using iron and nickel as binder metals in cemented carbides. The present work shows how calculations can be used in the process of selecting suitable compositions of these complex alloys. The calculations are compared with new experimental results on Ni-Fe-Co-WC-based cemented carbides as well as with results published in the literature. (C) 1997 Elsevier Science Limited.