Effect of nano-ZrO sub(2) on microstructure and thermal shock behaviour of Al sub(2)O sub(3)/SiC composite ceramics used in solar thermal power

• Published in: Journal of Wuhan University of Technology. Materials science edition 2011-04, Vol.26 (2), p.284-288
• Main Authors: Xu, Xiaohong, Jiao, Guohao, Wu, Jianfeng, Leng, Guanghui, Fang, Binzheng, Zhao, Fang
• Format: Article
• Language: English
• Subjects: Bend strength; Ceramics; Nanocomposites; Nanomaterials; Nanostructure; Silicon carbide; Solar heating; Solar power generation
• ISSN: 1000-2413; 1993-0437
• DOI: 10.1007/s11595-011-0214-4

The Al sub(2)O sub(3)-ZrO sub(2 )(3Y)-SiC composite ceramics used in solar thermal power were prepared by micrometric Al sub(2)O sub(3), nano-ZrO sub(2) and SiC powders under the condition of pressureless sintering. The bulk density and bending strength of samples with 10vol% nano-ZrO sub(2) sintered at 1480 degree C were 3.222 g/cm super(3) and 160.4 MPa, respectively. The bending strength of samples after 7 times thermal shock tests (quenching from 1000 degree C to 25 degree C in air medium) is 132.0 MPa, loss rate of bending strength is only 17%. The effect of nano-ZrO sub(2) content on the microstructure and performance of Al sub(2)O sub(3)-ZrO sub(2 )(3Y)-SiC composite ceramic was investigated. The experimental results show that the bending strength of samples with above 10vol% nano-ZrO sub(2) content has decreased, because the volume expansion resulting from t-ZrO sub(2) to m-ZrO sub(2) phase transformation is excessive; Adding proper nano-ZrO sub(2) would be contributed to improve the thermal shock resistance of the composite ceramics. The Al sub(2)O sub(3)-ZrO sub(2 )(3Y)-SiC composite ceramic has promising potential application in solar thermal power.