Influence of Various Alloying Elements on WC-Ni Hardmetals Produced by FAST

The substitution of cobalt in hardmetals has a crucial economic role, since increasing costs driven by the demand for Li-ion batteries can lead to higher prices for the majority of hardmetal grades which depend on cobalt as binder metal. Nickel has already proven to be a possible substitute. However, so far it cannot compete with cobalt in terms of mechanical properties. Therefore, in this work a systematic investigation on various alloying elements in nickel-based binder systems for hardmetals was done. A further goal of this study was the reduction of needed sintering temperatures which can lead to less energy consumption for the sintering process. The trials were carried out using field assisted sintering. Subsequent SinterHIP treatment was done to investigate the quasi thermodynamically stable state. The chosen alloying elements are iron, manganese, copper, silicon, and germanium. For some combinations, hardmetals with a novel nickel-based binder alloy could be successfully prepared.