The adsorption and dissolution properties of iron surfaces in liquid lithium and lead under a fusion environment
The adsorption and dissolution properties of iron surfaces in liquid lithium and lead under a fusion environment
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DOI：
10.1016/j.jnucmat.2019.06.033
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发表时间：
2019-07
影响因子：
3.1
通讯作者：
Yichun Xu;Yange Zhang;Xiang-yan Li;Wei Liu;C. Liu;Q. Fang;H. Deng;Zhiguang Wang
中科院分区：
文献类型：
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作者：
Yichun Xu;Yange Zhang;Xiang-yan Li;Wei Liu;C. Liu;Q. Fang;H. Deng;Zhiguang Wang
聚变装置中液态锂(Li)和铅锂(Pb-Li)共晶合金会因溶解腐蚀而导致铁(Fe)基结构材料的退化。然而，溶解腐蚀的性质和潜在机制还不是很清楚。通过第一性原理计算，通过对Li、Pb原子在Fe表面(001)、(110)和(111)表面的吸附和逃逸的能量学评价，研究了钢在液态Li和Pb中的溶解腐蚀。我们的能量学结果表明，Li和Pb原子都以能量的方式优先吸附在所考虑的Fe表面，并进一步加速了表面Fe原子的逃逸。与吸附和逃逸过程有关的溶解腐蚀强烈地依赖于表面结构、被吸附的锂或铅原子的覆盖度以及工作环境的温度。在液态Li中，由于Fe表面的结构性质，如配位数，其溶解腐蚀强度可按(110)<；(001)<；(111)排序。Li原子覆盖率的增加增加了Fe原子从表面逃逸的几率，这可能导致严重的溶解腐蚀。此外，随着温度的升高，Li原子从液相吸附到表面，加剧了溶解腐蚀。在液态铅中，Fe表面的溶解腐蚀也与表面结构、覆盖度和温度有关，但比液态Li中的溶解腐蚀严重。最后，根据铅锂合金在液态锂和铅中的溶解特性，提出了铅锂合金中铁表面的溶解机理。
Liquid lithium (Li) and lead-lithium (Pb–Li) eutectic alloy in fusion devices could result in the degradation of iron (Fe)-based structural materials due to the dissolution corrosion. However, the properties and underlying mechanism of the dissolution corrosion are not well understood. By performing first-principles calculations, we investigate the dissolution corrosion of steels in liquid Li and Pb through energetics evaluation on the adsorption of Li and Pb atoms and the escape of Fe atoms on Fe surfaces (001),(110) and (111). Our energetics results indicate that both Li and Pb atoms energetically prefer to adsorb on the considered Fe surfaces, and further accelerate the escape of surface Fe atoms. The dissolution corrosion related to the adsorption and escape processes exhibits strong dependence on surface structures, the coverage of adsorbed Li or Pb atoms, and the temperature of working environment. In liquid Li, the intensity of the dissolution corrosion of the Fe surfaces can be ordered by (110)<(001)<(111) due to their surface structure properties, such as the coordination numbers. The increasing coverage of Li atoms increases the escape probability of Fe atoms from the surfaces, which could lead to severe dissolution corrosion. Moreover, increasing temperature aggravates the dissolution corrosion by promoting the adsorption of Li atoms from liquid phase on the surfaces. In liquid Pb, the dissolution corrosion of Fe surfaces is also surface structure, coverage and temperature dependent, however, is severer than that in liquid Li. Finally, the dissolution mechanism of Fe surfaces in Pb–Li alloys is proposed based on the dissolution properties in liquid Li and Pb.