Thermal conductivity of ceramics in the ZrO2-GdO1.5 system

被引:99
作者
Wu, J
Padture, NP [1 ]
Klemens, PG
Gell, M
García, E
Miranzo, P
Osendi, MI
机构
[1] Univ Connecticut, Dept Met & Mat Engn, Inst Sci Mat, Storrs, CT 06269 USA
[2] Univ Connecticut, Dept Phys, Inst Mat Sci, Storrs, CT 06269 USA
[3] CSIC, Inst Ceram & Vidrio, E-28049 Madrid, Spain
基金
美国能源部;
关键词
D O I
10.1557/JMR.2002.0462
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
Low thermal conductivity ceramics in the ZrO2-GdO1.5 system have potential in structural (refractories, thermal barrier coatings, thermal protection) and nuclear applications. To that end, the thermal conductivities of hot-pressed xGdO(1.5) . (1 - x)ZrO2 (where x = 0.05, 0.15, 0.31, 0.50, 0.62, 0.75, 0.89, and 1.00) solid solutions were measured, for the first time, as a function of temperature in the range 25 to 700 degreesC. On the ZrO2-rich side, the thermal conductivity first decreased rapidly with increasing concentration of GdO1.5 and then reached a plateau. On the GdO1.5-rich side, the decrease in the thermal conductivity with increasing concentration of ZrO2 was less pronounced. The thermal conductivity was less sensitive to the composition with increasing temperature. The thermal conductivity of pyrochlore Gd2Zr2O7 (X = 0.5) was higher than that of surrounding compositions at all temperatures. A semiempirical phonon-scattering theory was used to analyze the experimental thermal conductivity data. In the case of pure ZrO2,and GdO1.5, the dependence of the thermal conductivity to the absolute temperature (T) was less than 1/T. Therefore, the minimum thermal conductivity theory was applied, which better described the temperature dependence of the thermal conductivity of pure ZrO2 and GdO1.5. In the case of solid solutions, phonon scattering by cation mass fluctuations and additional scattering by oxygen vacancies on the ZrO2-rich side and by gadolinium vacancies on the GdO1.5-rich side seemed to account for the composition and temperature dependence of the thermal conductivity.
引用
收藏
页码:3193 / 3200
页数:8
相关论文
共 29 条
[1]  
[Anonymous], 1996, FUNDAMENTALS CERAMIC
[2]  
[Anonymous], 1969, Thermal conductivity
[3]  
[Anonymous], 1996, THERMAL CONDUCTIVITY
[4]   Pseudo-plasticity of monoclinic Gd2O3 [J].
Balestrieri, D ;
Philipponneau, Y ;
Decroix, GM ;
Jorand, Y ;
Fantozzi, G .
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY, 1998, 18 (08) :1073-1077
[5]  
BEVAN DJM, 1979, HDB PHYSICS CHEM RAR, V3, P412
[6]  
Green D.J., 1989, Transformation Toughening of Ceramics
[7]   PHOTOINDUCED THERMAL-CONDUCTIVITY CHANGES IN ALUMINUM NITRIDE [J].
HARRIS, JH ;
ENCK, RC ;
YOUNGMAN, RA .
PHYSICAL REVIEW B, 1993, 47 (09) :5428-5431
[8]  
Klemens P.G., 1991, HIGH TEMP-HIGH PRESS, V23, P241
[9]  
Kubaschewski O., 1967, METALLURGICAL THERMO
[10]  
MAGLIC KD, 1992, E146192 ASTM