Oxidation and tribological behaviour of an Fe-based MMC reinforced with TiCN particles

The oxidation behavior of a metal matrix composite based on a high-speed steel (HSS, M2 grade) as a matrix and 50 vol% of TiCN particles as reinforcement has been studied, as well as the M2 steel as a reference. The oxidation behavior of the materials were tested at 500 °C and 800 °C in static laboratory air. The values of the mass gain and the examination of the oxide scales by scanning electron microscopy and X-ray diffraction demonstrated that the composite material remains stable under oxidizing conditions to higher temperatures than the base steel. The wear tests were carried out at room temperature under dry sliding wear condition by the pin-on-disk technique, under two different loads (5 N and 10 N). The mass loss of the samples were measured after different sliding distances (up to 8000 m), and the wear tracks were examined by SEM. It was found that the predominant wear mechanism is abrasion for both systems, and that the interaction between TiCN particles and metal matrix leads to improve the wear resistance of composite material in comparison with the high speed steel.