Solidification of the Eutectic Alloy in the Gallium–Indium System

The influence of the overheating of the Ga–14.2 mol % In eutectic alloy melt on the presolidification cooling is studied on 2-g samples by cyclic thermal analysis. In the case of the overheating of the liquid eutectic above the eutectic temperature T e = 288.3 by 28–30 K and subsequent cooling, the overheating dependence of the supercooling has a continuously increasing character. The limiting supercooling is ~25 K regardless of the preliminary overheating of the melt, from 30 to 100 K. The solidification from the supercooled state is found to have an “explosive” character at a rate of 40–45 K/s. The supercooling is not affected by long-term (for several hours) isothermal holding of the melt in overheated and supercooled states. The kinetic and thermodynamic parameters of the eutectic solidification are calculated using fusibility thermograms.