Grain boundary strengthening in alumina by rare earth impurities
Grain boundary strengthening in alumina by rare earth impurities
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DOI：
10.1126/science.1119839
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发表时间：
2006-01-13
期刊：
影响因子：
56.9
通讯作者：
Ikuhara, Y
中科院分区：
文献类型：
--
作者：
Buban, JP;Matsunaga, K;Ikuhara, Y
杂质掺杂常常改变或改善材料的性能。在氧化铝中，晶界在变形机制中起着关键作用，特别是在高温蠕变过程中晶界滑动的现象。我们用原子分辨显微镜和高精度计算阐明了氧化铝晶界的原子级结构及其与Y掺杂抑制蠕变的关系。我们发现，Y沿晶界偏聚到非常局域化的区域，改变了晶界的局部结合环境，从而加强了晶界对机械蠕变的抵抗。
Impurity doping often alters or improves the properties of materials. In alumina, grain boundaries play a key rote in deformation mechanisms, particularly in the phenomenon of grain boundary sliding during creep at high temperatures. We elucidated the atomic-scale structure in alumina grain boundaries and its relationship to the suppression of creep upon doping with yttrium by using atomic resolution microscopy and high-precision calculations. We find that the yttrium segregates to very localized regions along the grain boundary and alters the local bonding environment, thereby strengthening the boundary against mechanical creep.