Calculation of Liquidus Temperature of Practical Al–Si–Cu Alloys Using the ESTPHAD Method

Accurate knowledge of the liquidus temperature of aluminium alloys is essential for the design and control of solidification processes. In this study, the ESTPHAD (ESTimation of PHAse Diagram) method is applied to calculate the liquidus temperatures of practical Al–Si–Cu casting alloys containing minor alloying elements. The calculated values are systematically compared with Thermo-Calc results and experimental data reported in the literature. The results demonstrate that, for alloys with Cu contents below 5 wt% and minor alloying additions below 1 wt%, the liquidus temperature can be estimated with an average error of approximately 1 K using only binary interaction functions.