Dependence of Particle Parameters in Flight and Coating Character on Power of the Electric Supply at Plasma Spraying of TiO2

The influence of input power on the spayed powder and final coating was quantified for particular case of water-stabilized plasma spray torch (WSP (R)) and ceramic coating formed from titanium dioxide (TiO(2)). All other spray setup parameters were fixed during the experiment with electric supply power as the only variable factor. In-flight particles were characterized by Doppler particle velocimetry, microstructure of the coatings was observed by microscopic techniques and 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. The results indicate that the higher power means better coating quality - its microstructure and mechanical performance. This substantial difference has the same trend for both power supplies utilized for the testing.