Thermal conductivity of yttria-stabilized zirconia-hafnia solid solutions
Thermal conductivity of yttria-stabilized zirconia-hafnia solid solutions
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DOI：
10.1016/j.actamat.2006.06.038
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发表时间：
2006-11-01
期刊：
影响因子：
9.4
通讯作者：
Clarke, David R.
中科院分区：
文献类型：
--
作者：
Winter, Michael R.;Clarke, David R.
本文报道了氧化钇稳定的氧化锆-氢氧化铝固溶体系列的导热系数随温度的变化规律。对于所有研究的成分，完全致密材料的导热系数几乎与温度无关，最高可达1000摄氏度，这是我们测量的极限。报道了固溶体合金化的强烈效果，其中混合的氧化锆-氢氧化铝化合物的导热系数低于固溶体系列中的氧化钛稳定的氧化锆或氧化钛稳定的氢氧化铝的端元。导热系数最低的组份约为等摩尔氧化锆-氧化钛，其导热系数比目前热障涂层中使用的标准8YSZ组合物低约25%。虽然固溶体在低温下通常具有较低的导热系数，其中导热系数与温度有关，但这是第一个关于固溶体合金化降低最小导热系数的值的报告，最低导热系数是高温导热系数的极限。这种效应归因于氧化锆阳离子亚晶格上的质量无序，其中的Zr4+离子被取代并与Hf4+离子混合，降低了声子的平均自由程。这是对Y3+稳定剂引入的空位造成的阴离子亚晶格中的无序的补充。(C)2006 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
The thermal conductivity of the yttria-stabilized zirconia-hafnia solid solution series as a function of temperature is reported. For all the compositions studied, the thermal conductivity of the fully dense materials is almost temperature independent up to 1000 degrees C, the limit of our measurements. A strong effect of solid solution alloying is reported with the mixed zirconia-hafnia compositions having lower thermal conductivity than either yttria-stabilized zirconia or yttria-stabilized hafnia end members of the solid solution series. The compositions with the lowest thermal conductivity are approximately equimolar zirconia-bafnia, and these have a thermal conductivity approximately 25% lower than that of the standard 8YSZ composition currently used in thermal barrier coatings. Although solid solutions generally have lower thermal conductivity at low temperatures, where the conductivity is temperature dependent, this is the first report of solid solution alloying lowering the value of the minimum thermal conductivity, the high-temperature limit of thermal conductivity. The effect is attributed to mass disorder on the cation sublattice of zirconia in which Zr4+ ions are replaced and mixed with Hf4+ ions, decreasing the phonon mean free path. This is in addition to the disorder in the anion sublattice created by the vacancies introduced by the Y3+ stabilizer. (c) 2006 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.