Simulation of SPS Process for Fabrication of Thermoelectric Materials with Predicted Properties

Spark plasma sintering (SPS) is a promising method for fabrication of thermoelectric materials. The electric and thermal fields in the SPS process have been simulated by using the finite element method to model an SPS-511S experimental setup. Investigation of thermoelectric materials based on Bi2Te3 solid solutions revealed that the temperature measured close to the sample during application of the electric current could be reproduced by the simulation. Modification of the compression mold configuration could be used to alter the electric and thermal conditions, adjust the Joule heat released in the setup elements, and create a gradient temperature field during the SPS process. The temperature-time dependence in the sample was also studied, revealing that the temperature difference along the vertical axis may reach hundreds of degrees. Prediction of the sintering temperature in each layer may allow further prediction of the thermoelectric properties of the sample. More accurate modifications of the SPS process based on such computer simulations may help to form structures with macroscopically inhomogeneous and functionally graded legs.