Thermal Conductivity of Thin Walled Compacted Graphite Iron Castings

Abstract

This study addresses the effect of the cooling rate and of titanium additions on the exhibited microstructure and thermophysical parameters of thin-walled compacted graphite iron (TWCI) castings as determined by changing the moulding materials (silica sand and insulating sand LDASC), and Ferro Titanium. The research was conducted for thin-walled iron castings with a 3-mm wall thickness. The tested material represents the occurrence of graphite in the shape of nodules, flakes (C and D types, according to ISO Standard) and compacted graphite with a different shape factor and percent of nodularity. Thermal conductivity has been evaluated by the laser flash technique in a temperature range of 22–600°C. The results show that the cooling rates together with the titanium content largely influence the microstructure, graphite morphology and finally thermal conductivity of thin walled castings. Finally mechanism for thermal conductivity profile as a function of temperature for thin wall castings with different graphite morphology is provided.