Viscous fluid approximation when simulating Bi2Te3 based thermoelectric material extrusion process
Keywords:
extrusion, thermoelectric material, modelingAbstract
In the process of extrusion, billets of material are deformed under virtually perfect plastic conditions. Such a process can be simulated using the hydrodynamic theory, where a material is regarded as a fluid of very high viscosity which is a function of velocity and temperature. The internal friction of the moving layers of the material serves as a heat source, so it is also necessary to use the heat transfer equation in conjunction with the hydrodynamic aspect of the problem. This approach is especially effective for simulating the extrusion process of thermoelectric materials when large deformations are present. This paper presents the results of an object-oriented computer simulation of the process of hot extrusion of Bi2Te3 based thermoelectric material. Cases of producing cylindrical samples of circular cross section for various matrix configurations for single-stage and multi-stage extrusion are considered. The distributions of temperature and flow velocity of material in the matrix are obtained, as well as stress distribution in the matrix due to external pressure and thermal loads, which formed the basis for optimization of equipment for producing extruded thermoelectric material. Bibl. 5, Fig. 8, Тabl. 1.
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