Investigation of Cast Iron Processing to Produce Controlled Dual Graphite Structure in Castings

The change in graphite shape from flake to spheroidal significantly increases the strength of cast iron while simultaneously decreases thermal conductivity to about half of the value in flake graphite iron. In many industrial applications, such as the cylinder head of diesel engine, a combination of high strength and thermal conductivity is essential. A compromise would be to use compacted graphite iron, while a more effective way would be to develop controlled distribution of the dual graphite structure that matches a specific region’s function of the casting design. In this study, the process of casting such functionally region-specific material was modeled and experimentally investigated.