Cobalt oxide as a raw material for the production of WC-Co cemented carbides and its advantages for the pressing process

Abstract

In general the cemented carbide industry uses cobalt as a raw material for the production of WC-Co cemented carbide. However the here presented publication shows that even if 100% of the cobalt of the cemented carbide is replaced with Co3O4 prior sintering, dense WC-Co cemented carbide can be achieved when the sintering program contains a hydrogen treatment. The point of the matter when using a cemented carbide powder which contains cobalt oxide (WC-Co3O4) are the huge differences in the compressibility compared to a conventional powder (WC-Co). Depending on the ratio of cobalt and cobalt oxide in the cemented carbide composition the compressibility of the powder/granule can be adjusted in a wide range. This opens up the possibility to produce different cemented carbide grades with an identical compressibility. As a consequence costs for additional pressing tools can be saved.