Wear resistance and damping capacity of semisolid processed hypoeutectic grey cast iron

Abstract

The wear resistance and damping capacity of hypoeutectic grey cast iron (carbon equivalent =3·59%) were investigated as a function of the relative amount of primary fraction of solid. In the present study the authors have used a cooling plate to produce semisolid iron slurry. Sand mould castings with 14 mm strip thickness were used in the present study. For comparison, damping capacity was also carried out on ordinary ductile iron specimen made from Y block with 15 mm thickness. The wear resistance of grey cast iron was improved using the semisolid processing. The wear rate of grey iron decreases as the fraction of solid increases until 0·12. Further increase of fraction of solid increases the wear rate due to formation of interconnected fine graphite type D. Frictional wear mechanism of iron casting is strongly affected by shape, size and arrangement of graphite precipitates. For semisolid casting at high loading, increasing the sliding speed increases the rate of oxidation and consequently changes the wear mechanism. The damping capacity of semisolid grey cast iron is lower than ordinary grey iron but higher than ductile iron for all strain amplitude ranges. The damping capacity of both ordinary and semisolid grey cast iron increases with strain amplitude.