Abstracts Engineering

Durville casting of nickel-iron valve bars

by Jason David Swan

The manufacture of an air-melted, Durville cast, nickel-iron based superalloy, XD1102, for the automotive industry has been studied. In particular the formation of the air-gap and the heat transfer between the casting and the mould interface has been measured for an aluminum alloy, LM25 and the XD1102 alloy cast into the same size mould. The experimental results were used to verify ProCAST 3D model simulations providing confidence that the software could be used for practical applications where destructive measuring techniques is not viable. A second aspect of this thesis was to identify, trace the origin of, illustrate the root cause analysis, and the mitigation of a feature which has been observed on numerous valve heads. Lastly the investigation into whether the substantial thermo-mechanical work received by an ingot after casting minimised the benefits of a carefully poured cast via the Durville method has been discussed.