Characterization of Graphite Flakes in Grey Iron Microstructure

Cast irons are important engineering materials which possess a wide range of attractive properties. Their properties are significantly dependent on the microstructure of the cast and cast iron components. A way of controlling the microstructure of cast iron is through the control of cooling rates during solidification. To control cooling rate, the heat storage capacity (HSC) of the mould is important. This paper presents the report of a study on the characteristic effects of graphite flake sizes on some mechanical properties of grey cast iron. Six mould materials with HSCs ranging from 1.52 to 2.16 kJ m−2 K−1 s−1/2 were prepared and used to cast some grey cast iron samples whose microstructures were observed by optical microscopy. Mechanical properties of the grey iron were evaluated. The results show that the properties increased with the HSC of the mould. In addition, the microstructures show a dependence on HSC of the mould.