Study of nanocomposite hafnia and zirconia based layers produced by plasma spraying

Nanostructured and nanocomposite layers NiCoCrAlY+ ZrO 2 -7%Y 2 O 3 , ZrO 2 -7% Y 2 O 3 +HfO 2 -9%Y 2 O 3 , HfO 2 -9%Y 2 O 3 with thickness of ∽ 20 μm were formed by low pressure plasma spraying. The structure and composition of the layers have been studied using a scanning electron microscopy, X-ray microanalysis, and XRD analysis. Thermal stability of the coatings has been analyzed using synchronous thermal analysis at temperatures up to 1600 °C. The results of structure and composition analysis of ZrO 2 -7%Y 2 O 3 +HfO 2 -9%Y 2 O 3 layer suggest the formation ofnanocomposite co-doped regions of the ZrO 2 -HfO 2 -Y 2 O 3 solid solution. The layer has greater thermal stability at temperatures up to 1600 ° C and a smaller subgrain size (∽ 33 nm) than for the ZrO 2 -7% Y 2 O 3 and HfO 2 -9%Y 2 O 3 layers.