Enhanced Grain Boundary Mobility in Yttria-Stabilized Cubic Zirconia under an Electric Current
Enhanced Grain Boundary Mobility in Yttria-Stabilized Cubic Zirconia under an Electric Current
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DOI：
10.1111/j.1551-2916.2011.04800.x
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发表时间：
2011-12-01
影响因子：
3.9
通讯作者：
Chen, I-Wei
中科院分区：
文献类型：
--
作者：
Kim, Seung-Wan;Kim, Soo Gil;Chen, I-Wei
研究了电流下 8 mol% Y2O3 稳定氧化锆陶瓷 (8YSZ) 的晶粒生长情况。阴极侧的晶粒生长增强开始于 1150 摄氏度，远低于传统的烧结温度，而阳极侧的晶粒生长在 1400 摄氏度之前处于休眠状态。在完全致密的样品中，晶粒尺寸发生突然转变，两侧的晶粒尺寸相差超过 10 倍。多孔样品在阴极侧也经历了更快的致密化，但晶粒生长被推迟，直到首先达到全密度。估计阴极侧晶界扩散率的表观活化能比正常晶界扩散低约1eV。这些结果归因于阴极侧积累的过饱和氧空位，导致阳离子还原，从而降低了其迁移势垒。
Grain growth in 8 mol% Y2O3-stabilized zirconia ceramics (8YSZ) under an electric current has been investigated. Enhanced grain growth on the cathode side starts at 1150 degrees C, well below the conventional sintering temperature, while grain growth is dormant on the anode side until 1400 degrees C. In fully dense samples, the grain size undergoes an abrupt transition, differing by a factor of more than 10 on the two sides. Porous samples also experience faster densification on the cathode side, but grain growth is postponed until full density is first reached. Estimated grain boundary diffusivity on the cathode side has an apparent activation energy about 1 eV lower than that of normal grain boundary diffusion. These results are attributed to supersaturated oxygen vacancies accumulated on the cathode side, causing cation reduction that lowers their migration barrier.