Cemented Carbides Alloyed with Ruthenium, Osmium, and Rhenium

A study was made of the structure and mechanical properties of WC ― Co cemented carbides alloyed with Ru, Re, and Os. It was shown that the alloying elements form solid solutions with the binder phase, Co(Ru, W, C), Co(Re, W, C), Co(Os, W, C), which have higher microhardnesses and elastic moduli than the solid solution Co(W, C). Ruthenium, rhenium, and osmium reduce the stacking fault energy of the cobalt phase and promote the transformation of the cubic modification of cobalt to the hexagonal. This results in precipitation hardening of the binder phase. Additions of Ru, Re, and Os increase the hardness, and bend, compression and yield strengths, of WC ― Co alloys. Examples of the successful use of WC ― Co cemented carbide tools alloyed with noble metals for the machining of heat-resistant alloys and high-alloy steels are given.