Investigating cooling curve profile and microstructure of a squeeze cast Al–4%Cu alloy

Cooling curves were obtained to estimate solidification parameters of a squeeze cast Al–4%Cu alloy under different processing conditions, while microstructural analysis was carried out to investigate grain morphology obtained for the different test runs. The results indicated not only an increase in cooling curve gradient with increase in pressure, but also a change in cooling curve profile with changes in superheat and die temperature. Solidification range was also affected with an increase in liquidus when superheat was high while solidification rate was decreased when superheat was low and die temperature was increased. Microstructure showed refinement, dendritic growth formation and a suppression of both precipitated phase as well as micro-segregation with an increase in cooling rate due to application of pressure. The investigation is expected to provide important insight into the solidification behavior under pressure of an Al–4%Cu alloy that can be used to evaluate its casting feasibility as well as give basic input information for simulation purposes.