Microstructure and thermoelectric properties of low-pressure plasma-sprayed FeSi2 coatings

β-FeSi₂ semiconductors have been considered as a promising thermoelectric material because of its great capability to convert thermoelectric energy within 500-1200K, to resist against oxidation, to represent cheap rich raw material resources. Though β-FeSi₂ has many advantages among all thermoelectric materials, many difficulties have to be overcome during its preparation. Current β-FeSi₂ preparation processes include: generic powder metallurgy and melting-casting method, electron beam deposition, chemical vapor deposition, physical vapor deposition. For the film, the deposition rate is low and higher cost for the conventional deposition methods. This paper aims to present the application of the low pressure plasma spraying method to obtain β-FeSi₂-based thermoelectric material. Analyses of alloy phase components, microstructure, electric conductivity, Seebeck coefficients were performed and the results shown that this method can be considered as an alternative method to elaborate high quality β-FeSi₂-based thermoelectric material and be able to application of a large area quickly and cheaply.