Study of Al/Cu rich phases formed in A356 alloy by inserting Cu wire in pattern in LFC process

Al/Cu alloys are one of the most frequent aluminum alloys used in casting industry. In this research a recently introduced technique (inserting in-polystyrene pattern wire technique or IIPPW method) was used to produce and investigate some of Al/Cu rich phases which may form in Al alloys. Full mould process was performed for preparing the samples. Following to the pouring and solidification of the test bars, samples were cut in four sections along longitudinal and transverse directions and from the interface of Cu-insert with the matrix before being subjected to microstructural investigation by energy dispersive X-ray and SEM technique. A concentration of Cu-rich phases and other phases such as δ, AlCu, Al2Cu, Si particles and Fe containing intermetallic were found in the interface of Cu wire and the matrix. The technique introduced in this research seems to be a simple and valuable tool for studying the effect of various elements (inserted as a core in the polystyrene pattern, especially in the wire form) on pure metals and/or alloys.