Low‐Thermal‐Conductivity Rare‐Earth Zirconates for Potential Thermal‐Barrier‐Coating Applications
Low‐Thermal‐Conductivity Rare‐Earth Zirconates for Potential Thermal‐Barrier‐Coating Applications
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DOI：
10.1111/j.1151-2916.2002.tb00574.x
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发表时间：
2004-12
影响因子：
3.9
通讯作者：
Jie Wu;Xuezheng Wei;N. Padture;P. Klemens;M. Gell;E. García;P. Miranzo;M. Osendi
中科院分区：
文献类型：
--
作者：
Jie Wu;Xuezheng Wei;N. Padture;P. Klemens;M. Gell;E. García;P. Miranzo;M. Osendi
稀土锆酸盐已被确定为一类可能用于燃气轮机热障涂层的低导热陶瓷。为了记录和比较重要的稀土锆酸盐的热导率，我们测量了下列热压陶瓷的热导率：(I)Gd2ZR2O7(焦绿石相)，(Ii)Gd2ZR2O7(萤石相)，(Iii)Gd2.58ZR1.57O7(萤石相)，(Iv)Nd2ZR2O7(焦绿石相)，(V)Sm2ZR2O7(焦绿石相)。我们还测量了目前热障涂层中常用的成分--常压烧结7wt%Y稳定氧化锆(7YSZ)的导热系数。所研究的所有稀土锆酸盐的导热系数几乎相同，在25°-700C的温度范围内，它们都比7YSZ的导热系数低∼30%。
Rare-earth zirconates have been identified as a class of low-thermal-conductivity ceramics for possible use in thermal barrier coatings (TBCs) for gas-turbine engine applications. To document and compare the thermal conductivities of important rare-earth zirconates, we have measured the thermal conductivities of the following hot-pressed ceramics: (i) Gd 2 Zr 2 O 7 (pyrochlore phase), (ii) Gd 2 Zr 2 O 7 (fluorite phase), (iii) Gd 2.58 Zr 1.57 O 7 (fluorite phase), (iv) Nd 2 Zr 2 O 7 (pyrochlore phase), and (v) Sm 2 Zr 2 O 7 (pyrochlore phase). We have also measured the thermal conductivity of pressureless-sintered 7 wt% yttria-stabilized zirconia (7YSZ)--the commonly used composition in current TBCs. All rare-earth zirconates investigated here showed nearly identical thermal conductivities, all of which were ∼30% lower than the thermal conductivity of 7YSZ in the temperature range 25°-700°C. This finding is discussed qualitatively with reference to thermal-conductivity theory.