Gas tunnel type plasma spraying deposition and microstructure characterization of silicon carbide films for thermoelectric applications

Gas tunnel type plasma spraying deposition has been applied successfully to the deposition of the SiC films on stainless-steel substrates. The microstructure and the surface morphology of the SiC films were characterized by means of X-ray diffraction (XRD) and scanning electron microscope (SEM). The control of the processing parameters such as powder feeding rate, composition of plasma working gases, spraying distance, and carrier gas flow rate allowed the deposition of dense, uniform, continuous, and high purity crystalline SiC films. The thickness of the SiC films varied from 3 to 10 μm. EDS analysis confirmed the presence of SiO2 in the deposited SiC films.