Abstract
To describe the reason why the life time of WC-Co cemented carbide tools is shortened, when the tools are applied for copper or copper alloys, the interfacial reaction at 1273K between the alloy and pure copper has been studied. The results obtained are as follows; Copper atoms diffused much more in the alloy than the amount of cobalt atoms diffusing in copper. Copper rich layer formed at the interface between tungsten carbide and binder phases in the diffusion area of copper in the alloy, leading to the embrittlement of the above interface and the sharp decrease in the strength of alloy. The thickness of diffusion area or the diffusion depth of Cu was varied according to the binder and carbon contents of the alloy used.
