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Effect of Hollow Spherical Powder Size Distribution on Porosity and Segmentation Cracks in Thermal Barrier Coatings
Author(s) -
Guo H. B.,
Murakami H.,
Kuroda S.
Publication year - 2006
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2006.01322.x
Subject(s) - materials science , porosity , thermal barrier coating , composite material , coating , particle size , deposition (geology) , volume (thermodynamics) , particle size distribution , particle (ecology) , thermal spraying , raw material , mineralogy , chemical engineering , physics , paleontology , oceanography , chemistry , organic chemistry , quantum mechanics , sediment , engineering , biology , geology
The effect of characteristics of hollow spherical (HOSP) powders on porosity and development of segmentation cracks in plasma‐sprayed thick thermal barrier coatings (TBCs) was investigated. Three powders with particle size ranges of 20–45, 53–75, and 90–120 μm were selected from a commercial HOSP powder feedstock for spraying the TBCs. The 20–45 μm powder has a higher deposition efficiency and a greater capability of producing segmented coatings than the other larger powders. Diagnostics of in‐flight particles show that the average surface temperature and velocity of the particles sprayed from the fine powder is higher by 250°C and 50 m/s compared with those sprayed from the 90 to 120 μm powder, respectively, due to its greater ratio of surface area to mass. The lower porosity of the coating sprayed from the fine powder is mainly attributed to the decreased volume of intersplat gaps and voids.