Abstract
It was found that the binder phase frequently appeared around Vickers hardness indentation (V.H.I.) to form dotted structure of binder in TiC-based cermets at high temperature, and this phenomenon was never found in WC-based cemented carbides. Then the present study as to the phenomenon was carried out using TiC-(0, 20) vol%TiN-20 vol%Mo2C-(5-20) vol%%Ni cermets in relation to the alloy composition, structure and hardness testing conditions. It was made clear that the appearance of the binder phase was influenced by the factors mentioned above, and also caused by the fact that the plastic flow of the binder phase under compressive stress due to V. H. I. occurred more easily than that of the alloy, depending on the alloy structures, testing temperatures, etc.
