Solidification of Gallium–Indium Alloys

Cyclic thermal analysis is used to study the effect of overheating Δ T + of a melt on the presolidification supercooling Δ T_L^ - of gallium–indium alloys. The existence of deep supercooling Δ T_L^ - with respect to the liquidus is found for hypoeutectic alloys, whereas, for hypereutectic alloys, the supercooling is found only with respect to solidus T E (eutectic transformation line). The activities and the coefficients of activity of constituents are calculated at the onset of quasi-equilibrium and nonequilibrium explosive solidification. When the composition approaches the eutectic one, the activity of both constituents is found to decrease.