Thermal simulation of thermoelectric material by zone-melting technique

The thermoelectric conversion efficiency of Bi-Te alloys is significantly affected by its microstructure. The columnar crystal structure can improve the thermoelectric conversion efficiency by raising the electrical conductivity σ and reduce the thermal conductivity κ, because of ZT α2σT/κ [1]. Zone-melting process is a method can directionally solidify and purify the ingot by a moving heater along the solid ingot. In this study, we setup a zone-melting model and use computer simulation techniques to simulate the heat transfer field and microstructure of Bi-Te alloys. We compared the vertical temperature gradients and the horizontal temperature gradients with different simulation parameters. In view of the fact that operation of the process is not easy, simulation system has not yet been verified accurately. The simulation results will be verified by the experiment. Furthermore, the verified numerical model will be used to investigate the optimal processing parameters.