Thermal expansion and thermal conductivity of SmxZr1−xO2−x/2 (0.1≤x≤0.5) ceramics
| Autor: | Jing Li, Yu Zhou, Bai-He Wang, Zhan-Guo Liu, Jia-Hu Ouyang |
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| Rok vydání: | 2009 |
| Předmět: |
Materials science
Process Chemistry and Technology Analytical chemistry Mineralogy Atmospheric temperature range Thermal diffusivity Thermal expansion Surfaces Coatings and Films Electronic Optical and Magnetic Materials Tetragonal crystal system Thermal conductivity visual_art Materials Chemistry Ceramics and Composites visual_art.visual_art_medium Dilatometer Ceramic Diffractometer |
| Zdroj: | Ceramics International. 35:791-796 |
| ISSN: | 0272-8842 |
| DOI: | 10.1016/j.ceramint.2008.02.016 |
| Popis: | A study was conducted of the effect of additions of samarium oxide on the thermal expansion and thermal conductivity of zirconium oxide for thermal barrier coatings. Sm x Zr 1− x O 2− x /2 (0.1 ≤ x ≤ 0.5) ceramic powders synthesized with a chemical-coprecipitation and calcination method were sintered at 1873 K for 15 h. Structures of the synthesized powders and sintered ceramics were identified by X-ray diffractometer. The morphologies of ceramic powders were observed by transmission electron microscope. The thermal expansion coefficients and thermal diffusion coefficients of Sm x Zr 1− x O 2− x /2 ceramics were studied with a high-temperature dilatometer and a laser flash diffusivity technique from room temperature to 1673 K. The thermal conductivity was calculated from thermal diffusivity, density and specific heat of bulk ceramics. Sm 0.1 Zr 0.9 O 1.95 ceramics consists of both monoclinic and tetragonal structures. However, Sm 0.2 Zr 0.8 O 1.9 and Sm 0.3 Zr 0.7 O 1.85 ceramics only exhibit a defect fluorite structure. Sm 0.4 Zr 0.6 O 1.8 and Sm 0.5 Zr 0.5 O 1.75 ceramics have a pyrochlore-type lattice. With the increase of Sm 2 O 3 content, the linear thermal expansion of Sm x Zr 1− x O 2− x /2 ceramics increases except for Sm 0.1 Zr 0.9 O 1.95 . The thermal conductivities of Sm x Zr 1− x O 2− x /2 ceramics ranged from 1.41 at 873 K to 1.86 W m −1 K −1 at room temperature in a test temperature range of room temperature to 1673 K, and the results can be explained by phonon scattering mechanism. |
| Databáze: | OpenAIRE |
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