Nat Mater. 2011 Oct 23;10(12):922-6. doi: 10.1038/nmat3150.
Oxide-dispersion-strengthened steels are the most promising structural materials for next-generation nuclear energy systems because of their excellent resistance to both irradiation damage and high-temperature creep. Although it has been known for a decade that the extraordinary mechanical properties of oxide-dispersion-strengthened steels originate from highly stabilized oxide nanoclusters with a size smaller than 5 nm, the structure of these nanoclusters has not been clarified and remains as one of the most important scientific issues in nuclear materials research. Here we report the atomic-scale characterization of the oxide nanoclusters using state-of-the-art Cs-corrected transmission electron microscopy. This study provides compelling evidence that the nanoclusters have a defective NaCl structure with a high lattice coherency with the bcc steel matrix. Plenty of point defects as well as strong structural affinity of nanoclusters with the steel matrix seem to be the most important reasons for the unusual stability of the clusters at high temperatures and in intensive neutron irradiation fields.
氧化物弥散强化钢因其优异的抗辐照损伤和高温蠕变性能，成为下一代核能系统中最有前途的结构材料。尽管十年来人们已经知道，氧化物弥散强化钢的非凡力学性能源自尺寸小于 5nm 的高度稳定的氧化物纳米团簇，但这些纳米团簇的结构仍不清楚，仍是核材料研究中最重要的科学问题之一。在这里，我们使用最先进的 Cs 校正透射电子显微镜对氧化物纳米团簇进行了原子尺度的表征。这项研究提供了令人信服的证据，证明纳米团簇具有缺陷的 NaCl 结构，与 bcc 钢基体具有很高的晶格一致性。大量的点缺陷以及纳米团簇与钢基体之间的强烈结构亲和力，似乎是纳米团簇在高温和强中子辐照场中具有异常稳定性的最重要原因。
