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Thermophysical Properties of (Mg x La 0.5−x Sm 0.5 ) 2 (Zr 0.7 Ce 0.3 ) 2 O 7−x (x=0, 0.1, 0.2, 0.3) Ceramic for Thermal Barrier Coatings
Author(s) -
Liu Ling,
Wang Fuchi,
Ma Zhuang,
Xu Qiang,
Fang Shige
Publication year - 2011
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.1551-2916.2010.04385.x
Subject(s) - pyrochlore , materials science , microstructure , thermal barrier coating , ceramic , thermal expansion , analytical chemistry (journal) , coprecipitation , calcination , mineralogy , phase (matter) , composite material , thermal conductivity , chemical engineering , chemistry , engineering , biochemistry , organic chemistry , chromatography , catalysis
A series of complex rare‐earth zirconates (Mg x La 0.5− x Sm 0.5 ) 2 (Zr 0.7 Ce 0.3 ) 2 O 7− x ( x =0, 0.1, 0.2, 0.3) ceramics for thermal barrier coatings (TBCs) were synthesized by coprecipitation–calcination method. Their phase composition, microstructure, and the thermophysical properties were investigated. The results showed that single‐phase (Mg x La 0.5− x Sm 0.5 ) 2 (Zr 0.7 Ce 0.3 ) 2 O 7− x ( x =0, 0.1, 0.2, 0.3) with pyrochlore structure were prepared, and the microstructure of the products were dense. The thermal conductivity of the ceramics remarkably decreased through doping up to x =0.2 with a minimum value around 1.57 W·(m·K) −1 . As a function of increasing x , the thermal expansion coefficient of (Mg x La 0.5− x Sm 0.5 ) 2 (Zr 0.7 Ce 0.3 ) 2 O 7− x decreased firstly and then increased. The maximum value (11.3 × 10 −6 K −1 ) was achieved for the sample with the same composite point x =0.2. These results imply that with respect to thermal properties the optimum material is (Mg 0.2 La 0.3 Sm 0.5 ) 2 (Zr 0.7 Ce 0.3 ) 2 O 6.8 for the ceramic layer in TBCs system.