Plasma sprayed TiO2: The influence of power of an electric supply on particle parameters in the flight and character of sprayed coating

The influence of input power on sprayed powder and final coating was quantified for a water-stabilized plasma spray torch (WSP^®) and ceramic coating formed from titanium dioxide (TiO₂). All other spray setup parameters were secured during the experiment with electric supply power as the only variable factor. In-flight particles were characterized by a Doppler particle velocimetry, the microstructure of the coatings was observed by microscopic techniques with computer image analysis, and phase composition was studied by X-ray diffraction. Various mechanical properties were measured – microhardness, surface roughness, and wear resistance in a slurry. Also other particular physical characteristics of the coatings – reflectivity and bandgap energy – were observed in their dependence on the supply power because they are associated with applications of the coatings. The higher the power the higher the coating quality will be: both its microstructure and mechanical performance. This substantial difference has the same trend for both power supplies utilized for the testing.