Quantitative Thermal Analysis of Solidification in a High-Temperature Laser-Scanning Confocal Microscope
Under near-equilibrium conditions, the concentric solidification technique proved to be an excellent way of studying in situ, solidification phenomena, but under rapid cooling conditions, the solid/liquid interface undergoes dynamic thermal and solute distributions. The current project aims to evaluate temperature distribution under rapid cooling conditions. A number of thermocouples are attached to the specimen surface and measured the temperature over the solidification period. The temperature profile within the liquid phase is measured separately by thinner thermocouple wires which are fixed to the crucible so that the surface tension of the molten liquid keeps the thermocouple suspended in the liquid pool. The dynamically changing temperature profile over the radial axis of the specimen under rapid cooling conditions is determined, including the all-important temperature at the solid/liquid interface. The calculated interface temperatures are utilized in phase-field simulations, and the results are found to be in excellent agreement with experimental results.