Microstructure and Wear Properties of In Situ Production of (Fe,Cr)7C3 Particulate Bundles Reinforced Iron Matrix Composites

In-situ production of (Fe,Cr)7C3 particulate bundles-reinforced iron matrix composites were prepared by infiltration casting between Cr wires and white cast iron at 1200°C plus subsequent heat treatment. The composites prepared under different heat treatment time were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), macrohardness test and pin-on-disc wear resistance test. The results show that the composite is mainly consist of (Fe,Cr)7C3 carbides and γ-Fe. The area of the particulate bundles gradually increases with the increase of heat treatment time, the microstructure evolved from eutectic to hypoeutectic, and the morphologies of the reinforcements present chrysanthemum-shaped, granular and intercrystalline eutectics, respectively. The (Fe,Cr)7C3 particulate bundles reinforced composite has high macrohardness and excellent wear resistance under dry sliding wear testing conditons.