Prediction of AlSi7MgLi Phases with Calphad Methodology

Abstract

The introduction of lithium (Li) in AlSi7Mg alloys has significant implications for their mechanical properties and phase composition. This study investigates the effect of lithium on the phases present in an AlSi7MgLi alloy with the chemical composition of 7% Silicon, 0.36% Magnesium, and 0.80 Lithium using Thermo-Calc software with calphad methodology. Thermo-Calc, a powerful computational tool for thermodynamic and phase equilibrium analysis, allows for precise simulation of microstructural evolution and phase transformations. This research provides a detailed thermodynamic assessment of the specified alloy composition, focusing on the stability and distribution of phases such as primary silicon, magnesium silicide, and lithium-containing phases. The objective is to understand how lithium affects the phase behaviour and properties of the alloy, guiding the development of optimized compositions for enhanced performance. The results from Thermo-Calc simulations will be compared with available empirical and theoretical data to validate the predictions. This study highlights the importance of computational tools in advancing materials science, enabling precise phase predictions and offering insights into the role of lithium in aluminium alloys.