Microstructures and Properties of Plasma-Sprayed Segmented Thermal Barrier Coatings
Abstract:Thermal barrier coatings (TBCs) with different levels of segmentation crack density were produced by spraying two types of ZrO2–8Y2O3 powders. The fused and crushed powder has a greater capability of forming segmented coatings than the hollow sphere (HOSP) one. The highly segmented coatings reveal much lower porosity compared with traditionally sprayed coatings, thereby compromising the property of thermal insulation of TBCs. Microstructure and thermal conductivity of the HOSP coatings are more sensitive to the changes in spray conditions. Segmentation cracks had a strong influence in decreasing Young's modulus of coatings. Fifty hours heat treatment at 1250°C had little effect on the mechanical property of the highly segmented coatings.
Document Type: Research Article
Affiliations: Materials Engineering Laboratory, National Institute for Materials Science, Tsukuba, Ibaraki 305-0047, Japan
Publication date: April 1, 2006