Thermal characteristics of induction heating in cold crucible used for directional solidification

Cold crucible can be used to directionally solidify TiAl based alloys because of its low contamination. In this study, TiAlNb, steel and aluminium charges were used to investigate the characteristics of heat transfer and temperature field. Experiments were designed to measure the temperature of the charges in induction heating of cold crucible. A 2-D finite element model was established to calculate the temperature field of the charges in induction heating. The calculated results are in good agreement with the measured values. The results show that the temperature rising in induction heating and the steady temperature are affected by the thermal properties of the charges. It is found that the temperature rising gradually slows down and reaches a steady temperature finally. TiAlNb charge exhibits the highest steady temperature compared with steel and aluminium. The time to reach the steady temperature depends on the material properties, the power and the charge position.