Modeling Temperature Gradient Evolution of CoSb₃ Material for Thermoelectric Devices during Spark Plasma Sintering

Abstract

The temperature distribution and evolution of Mo/Ti/CoSb₃ materials used as thermoelectric couples of devices during spark plasma sintering were simulated by finite element method, and the results agree well with the die interior temperature measured by thermocouple. The sample and punches have higher temperature in whole sintering process, the highest temperature region is existed in CoSb₃ region, and the radial temperature gradient in CoSb₃ region is obvious. It was confirmed by experiments that the temperature gradient in sample results in non-uniform microstructure and thermal conductivity difference. The temperature gradient increases with decreasing thermal conductivity and increasing electrical resistivity of CoSb₃-based compound, from the point of view of the thermal conductivity and electrical resistivity, respectively, the optimization method of the combined mechanical property and thermoelectric property of CoSb₃-based compound was proposed.