Effect of technology of thermoelectric BiSbTe alloys on structural, thermoelectric and mechanical properties

The parameters of the main technologies for producing thermoelectric materials are considered: zone melting and extrusion. The structure and properties of samples of thermoelectric BiSbTe alloys obtained by zone melting and hot extrusion are compared to identify the dependencies. The analysis was carried out using methods of X-ray phase analysis, metallographic analysis, Raman spectroscopy, investigation of thermoelectric properties by the probe method, and mathematical modeling. The dependences of the thermal EMF distribution over the cross section are obtained, and the experimental dependences are analyzed. As a result, it was revealed that the samples obtained by hot extrusion have a heterogeneity of structure and properties across the sample section, which is associated with a stress-strain state due to the presence of significant friction forces on the surface of the contact of the material with the matrix. No such patterns were found for samples obtained by zone melting.