Thermoelectric (TE) power generation from waste heat is recently attracted much attention as one of energy-saving technologies. In this paper, Co-doped n-type iron silicide semiconductor was plasma sprayed under various spray conditions to find the optimum spray-forming conditions. Then Co-doped iron silicide TE device with thickness ranging from 3 to 5 mm and the area of over 100 cm square was produced in the form of a plate or on tube. The paper examines the microstructure and evaluates thermal and electric properties. Paper includes a German-language abstract.

A hybrid technique that combines plasma spraying and metal diffusion treatment was developed to improve the density, hardness, and adhesion of carbide cermet coatings. In this study, which was conducted to assess the process, Cr3C2-NiCr was deposited on stainless steel substrates by atmospheric plasma spraying. The test specimens were then embedded in a powder mixture of chromium, alumina, and ammonium chloride and diffusion treated. Cross-sectional SEM imaging, X-ray diffraction, and microhardness testing found the resulting surface layer to be extremely dense with outstanding hardness and exceptional bonding strength.