Structural and morphological characteristics of plasma sprayed TiO₂-coatings

TiO₂ thin layers have been deposited on glass substrates using Plasma Spray technique. The TiO₂ starting powders are a laboratory grade commercial powders. Before spraying, to check the availability of the basic material for Plasma Spray technique, a series of characterization was conducted. The TiO₂ starting powders were identified its particle size using Particle Size Analyzer (PSA) resulting diameter at 90 % was 42.72 µm. X-Ray Diffractometer (XRD) measurement was done to identify the peaks of the basic material elements using Kα radiation at wavelength 1.5406 Å resulted TiO₂ of Anatase structure. Spray dry process was then conducted in order to get circular and free flowing particles for feedstock of plasma spray system. Distribution of particles showed a dominant of 20 µm diameter-free flowing particle. Plasma Spray process of TiO₂ powder furthermore was conducted on slide glass microscope under several parameter conditions such as power, flame-substrate distance and preheating treatment variation. The TiO₂/glass coatings with variation of flame-substrate distance (10 and 12 cm) resulted in 5.806 µm and 4.913 µm layer thickness with grain size in the range of 0.8-2 µm and 1-2.8 µm, respectively. XRD diffractogram results revealed that the TiO₂ layer are dominant in rutile phase but at a little higher of plasma power, low anatase phase existed. The preheated-plasma sprayed TiO₂ coatings were visibly di fussed into the glass substrate and resulted in dominant rutile phase (at 2 cycles preheating) but not existed in a longer preheating time (4 cycles preheating treatment). (author)