Computational and experimental investigation of microsegregation in an Al-rich Al–Cu–Mg–Si quaternary alloy

Abstract A new micromodel was developed to predict the microstructure and microsegregation in multicomponent alloys during dendritic solidification. The micromodel was directly coupled with multicomponent phase diagram calculations using a user friendly and robust phase diagram calculation engine—PanEngine. Solid back diffusion, undercooling and coarsening effects were included in this model, and the experimentally measured cooling curves were used as the inputs to carry out the microsegregation calculations. Microsegregation in Al–4.5 wt%Cu–1 wt%Si–0.5 wt%Mg alloy was experimentally investigated from directional solidification and electron probe microanalysis. Calculated results using this model are in accord with the experimental data, while results from the Scheil model deviate significantly from the experimental data.