Influence of Annealing on the Grain Growth and Thermal Diffusivity of Nanostructured YSZ Thermal Barrier Coating
Na WANG, Chungen ZHOU, Shengkai GONG
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
Abstract
The nanostructured zirconia coatings were deposited by atmospherically plasma spraying. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diraction were used to investigate the microstructure of the zirconia coatings. Thermal diusivity values at normal temperatures have been evaluated by laser ash technique. Eect of annealing on the microstructure evolution of the zirconia coating has been performed. The grains and thermal diusivity are increased with increasing annealing time and temperature. The grain growth is according to the GRIGC (the grain rotation induced grain coalescence) mechanism. The increase in thermal diusivity is attributed to the grain growth and the decrease in porosity of nanostructured zirconia coatings.
keywords:Grain size; Thermal barrier coating; Plasma spraying; Thermal diffusivity
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