|Title||Solution Precursor Plasma Spraying of TiO2 Coatings Using a Catalyst-Free Precursor
Posted by Rolando Candidato Jr.
|Authors||Key T. Simfroso, Shena Ramyr Cabo, Romnick Unabia, Angelito Britos, Pawel Sokolowski and Rolando T. Candidato, Jr.|
|Abstract||The microstructural characteristics and phase composition of solution precursor plasma-sprayed (SPPS) titania-based coatings using a catalyst-free precursor are reported in this work. An ethanol-based solution containing titanium isopropoxide was used to deposit TiO2 coatings. The thermal behavior of the solution precursor changed as its phase transformation temperature increased when the molar concentration was increased from 0.3 M to 0.6 M. Scanning electron micrographs showed that the surface of the coatings was composed of nano- and submicron-sized spherical particles (<1 ÃÂ¼m) with sintered and melted particles. The cross-sections showed a porous structure using lower concentrations and dense coating formation with micropores using higher concentrations, with thicknesses of about 5 ÃÂµmÃ¢ÂÂ8 ÃÂµm. Moreover, the coatings when the number of spray passes was increased were 16 ÃÂµmÃ¢ÂÂ20 ÃÂµm thick, giving an average layer thickness of 0.6 ÃÂµm deposited per spray pass in all cases. Phase analysis revealed the presence of both the anatase and rutile phases of TiO2 in coatings sprayed with various concentrations at various stand-off distances. More detailed discussion is presented with respect to the effects of the solution concentration, stand-off distance, and number of spray passes on the coatingÃ¢ÂÂs phase composition and microstructure.|
|Index terms / Keywords||titanium dioxide; solution precursor plasma spraying; microstructure|