Toughening of nontransformable t′-YSZ by addition of titania
Toughening of nontransformable t′-YSZ by addition of titania
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DOI：
10.1111/j.1551-2916.2007.01990.x
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发表时间：
2007-12-01
影响因子：
3.9
通讯作者：
Levi, Carlos G.
中科院分区：
文献类型：
--
作者：
Schaedler, Tobias A.;Leckie, Rafael M.;Levi, Carlos G.
用TiO（2）取代ZrO（2）可使单相四氢呋喃（t'）7YSZ的韧性提高一倍。这种增强是通过用Ti（4+）取代较大的Zr（4+）阳离子来增加晶胞的四方性而实现的。所观察到的行为是一致的铁弹增韧，但缺乏直接的证据的机制。向7YSZ中添加TiO（2）具有额外的益处，即它减少了耗尽的四斜晶系形式的可转化性：具体地，即使在1600摄氏度下平衡之后，随后进行低温退火，也没有观察到单斜相。这些性能的组合预示着在燃气涡轮机发动机中作为热障涂层的潜在应用。
Substitution of TiO(2) for ZrO(2) into single-phase tetragonal (t') 7YSZ has been shown to induce a twofold increase in toughness. This enhancement has been achieved by increasing the tetragonality of the unit cell, upon substituting Ti(4+) for the larger Zr(4+) cation. The observed behavior is consistent with ferroelastic toughening, but direct evidence of the mechanism is lacking. Adding TiO(2) to 7YSZ has the additional benefit that it diminishes the transformability of the depleted tetragonal form: specifically, no monoclinic phase was observed even after equilibration at 1600 degrees C, followed by low-temperature annealing. The combination of properties bodes well for potential application as a thermal barrier coating in gas turbine engines.