Characterization of the Thermoelectric Behavior of Plastically Deformed Steels

Abstract

Different studies on the thermoelectric behavior of metals and metal alloys expose an influence of plastic deformation on the Seebeck coefficient. At present a detailed, quantitative analysis and descriptions of the effects of plastic deformation are not available, even though the thermoelectric properties are of fundamental importance for both theory and application. Therefore, the impact of plastic deformations on the temperature-dependent thermoelectric behavior of steel alloys is introduced in this paper. To achieve this, a device based on the integral measuring method was built to measure the relative Seebeck coefficient of steel alloys to platinum at different temperature gradients and for several degrees of plastic deformation. Well-defined values of plastic deformation were realized by cold rolling. With this compressive forming technology, logarithmic deformation up to 2.2 was set for all steel samples. Increasing plastic deformation results in a significant change in the relative Seebeck coefficient for all tested steel alloys. A relation between the thermoelectric behavior and plastic deformation of steels can be clearly illustrated based on the combination of metallurgical examinations and measurements of microhardness. These results provide new insights into the thermoelectric mechanism in steels in diverse plastic deformation states.