Improving the Surface Properties of Gray Cast Iron through In-Situ Alloying

Conventionally, alloying elements are being added to the whole melt; however, in this research in-situ surface alloying of gray cast iron was employed to improve surface properties of the castings. Wires of pure copper with diameters of 0.4 and 0.8 mm were inserted and fixed at bottom of sand molds before melting. Chemical composition analysis revealed the presence of copper from surface to a depth of 1 cm. Microstructural investigations indicated that graphite type changed from A to D and E. Moreover, the content of graphite phase decreased while that of pearlite increased at the surface. Hardness was higher at surface of copper added samples. Wear resistant of the in-situ surface alloyed samples was better than the no-copper added ones.