Microstructure and properties of plasma sprayed Al-doped YSZ coatings
AbstractThe inuence of alumina additive from 1 to 5 wt. % upon the microstructure and ionic conductivity of ZrO2–8 mol % Y2O3 (YSZ) ceramics, deposited by means of plasma spray technology, was investigated. Plasma sprayed films have been analysed using scanning electron microscopy (SEM) and X-ray analysis (XRD). The microstructural examination reveals that alumina addition decreases the porosity and microcracks of plasma sprayed YSZ. Analysis of SEM micrographs shows that the amount of 5 wt. % alumina substantially improves the microstructure of plasma sprayed zirconia. The crystal structure of all plasma sprayed samples consists of cubic zirconia and α-alumina. By the data of ionic conductivity measurements, no signicant influence of annealing at 1073 K for 10 h was noticed on characteristic temperature dependences of σ for plasma sprayed YSZ. Alumina doping from 2 to 5 wt. % considerably increases the ionic conductivity of plasma sprayed zirconia. The higher values of ionic conductivity were obtained when 5 wt. % of Al2O3 powder was added to YSZ.
Keywords: films, microstructure-final, ionic conductivity, ZrO2, Al2O3
PACS: 52.77.Bn, 68.55.J-, 68.90.+g
Condensed Matter Physics and Technology