ALUMINA-STABILIZED ZIRCONIA COATINGS FOR HIGH-TEMPERATURE PROTECTION OF TURBINE-BLADES

Thin films of ZrO2-Al2O3 were deposited on fused silica, silicon, plat inum and stainless steel by sol-gel processing of organo-metallic comp ounds. Four precursors with different atomic ratios of ZrAl were prepa red. As deposited films were amorphous and annealing in air resulted i n crystallization and densification of ZrO2 phases. Thin films heated as low as 600 degrees C showed crystallinity with cubic phase. All com positions tested in this work crystallized into cubic phase upon heati ng regardless of the kind of substrate. The particle sizes of the zirc onia films were calculated from X-ray diffraction (XRD) data. Scanning electron microscopy (SEM) of the films showed similar morphology for the films on various substrates.