Seebeck Coefficient Modification via Extreme High-Speed Laser Material Deposition for Tool Materials

During blanking and cold forming of metals, thermoelectricity almost always occurs. While thermoelectric voltages can be used for temperature measurement via a tool-workpiece thermocouple, currents significantly influence adhesion formation. In both cases, the thermoelectric behavior of tool and workpiece materials, characterized by the Seebeck coefficient, plays a decisive role. While a large difference in coefficients increases the accuracy of temperature measurement, similar coefficients improve wear behavior. Currently, there is no method to adjust the Seebeck coefficient of materials without experimental procedures, which restricts the selection of tool materials based on their Seebeck coefficient. This study presents a novel approach for adjusting the Seebeck coefficient of tool steels using tailored coatings applied by extreme high-speed laser material deposition (EHLA). Therefore, an analysis was conducted to investigate the effects of chemical composition, substrate material and its heat treatment on the thermoelectric and mechanical behavior of the coating. The results demonstrate that targeted modification via tailored EHLA coatings is possible.