Temperature, C 1600 Binary Eutectic Systems with Complete Insolubility 1200 800 Al + L 400 0 0 12 20 20 L cooling L 12 Si heating The Eutectic Reaction (Al + Si) L+Si 577 C Al+Si 40 60 80 100 Wt.% Si Si Aluminium Silicon Phase Diagram Completely immiscible/insoluble phase diagrams 100 80 120 88 60 40 88 -88 Time-- 0Percent A 100-Percent B