Microstructure and properties of composites ring fabricated by centrifugal casting

Iron matrix composites ring reinforced with tungsten carbide particles(WCP) was fabricated by centrifugal casting method.Microstructure and properties of the composites ring,including interface microstructure,WCP-distribution in outer composites layer and inner Fe-C alloy microstructure of the ring were investigated by SEM,TEM,XRD,impact,hardness and wearing tests.The results show that the composites ring consistes of outer composites-layer and inner Fe-C alloy layer.The WCP particles are uniformly distributed in the outer composites layer with a volume fraction of about 80%.Hardness reaches to 80-85 HRA of the outer composites layer,and 73-76 HRA of the inner Fe-C alloy layer with impact toughness over 10 J/cm2.The inner Fe-C alloy microstructure consists of bainite,graphite and composite carbide.The wear rate of the composites is more lower than that of high-speed steel,and is same as that of the WC cemented carbide.