Alumina and titania films deposition by APS/ASPPS dual mode thermal spray equipment using Ar added N2 working gas

In order to develop a low cost oxide film deposition process with short duration time, a 1 kW class Atmospheric thermal plasma spray (APS)/Atmospheric solution precursor plasma spray (ASPPS) dual mode thermal spray equipment was manufactured and film depositions of alumina (Al2O3) and titania (TiO2) by APS and titania film deposition by ASPPS were carried out. Consequently, though intensive fluctuation with intensive abrasion of electrodes occurred during plasma jet generation in case of N2 working gas, the plasma jet was stabilized and the abrasion was dramatically diminished by slight addition of Ar to N2 working gas. Since the suction type feedstock feeder could be confirmed to be available not only for powder feedstock but also solution precursor feed stock. In the case of APS, lamellar structure alumina and titania films could be deposited. However, in the case of titania films deposited by APS, a phase transformation from anatase to rutile occurred partially during film deposition. Also in the case of ASPPS, titania films including rutile and anatase were deposited. From these results, the developed equipment was proved to be available as an APS/ASPPS dual mode thermal spray equipment and this technique was found to have high potential for a low-cost oxide film deposition process.