Influence of heat treatment on the high temperature oxidation mechanisms of an Fe–TiCN cermet

Abstract

In this study, the oxidation behaviour of an iron matrix cermet containing 50% vol. Ti(C,N) was investigated before and after heat treatment by oxidation tests performed in static air at temperatures between 500°C and 1000°C. The oxidation mechanism for this type of composite materials was established and it was found that the heat treated material presents lower mass gain than the as-sintered material at the early stages of the oxidation, due to the volatilisation of oxides. The oxidation behaviour of the sintered cermet was compared to those obtained for two commercial materials used in the fabrication of cutting tools, a high-speed steel and a cemented carbide, revealing a higher oxidation resistance for the iron matrix cermet due to the formation of a self-protective layer during the oxidation process.