Microstructure and mechanical properties of high speed steel with addition of ferrophosphorus on sintering temperature

Abstract

High speed steel (HSS) is one of the important engineering materials especially for cutting material due to its superior properties. In this work, M2 HSS with addition of ferrophosphorus (Fe3P) are processed using conventional powder metallurgy route; mixing, compaction and sintering. The main objective of this work is to investigate the microstructure and mechanical properties ie, hardness and transverse rupture strength (TRS) in addition of Fe3P on sintering temperature. The mixtures are compacted at 15 tonnes and sintered at sintering temperature of 1100°C, 1140°C, 1180°C and 1220°C. The microstructural analysis using scanning electron microscope (SEM) shows the level of porosity decreases as sintering temperature increases which has indicated that denser sintered samples are obtained at high sintering temperature. The hardness result is in the similar trend where the hardness increases as sintering temperature increases. The maximum hardness of 458 HV is obtained at sintering temperature of 1220°C. Although the TRS increases as the sintering temperature increases, the optimum TRS is observed at sintering temperature of 1180°C with a value of 2351 MPa.