Influence of symmetric tilt grain boundaries and/or Cr-rich α′ precipitates on irradiation damage in Fe-Cr-Al alloys: A molecular dynamics investigation

IF 3.2 2区工程技术 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of Nuclear Materials Pub Date : 2025-08-06 DOI:10.1016/j.jnucmat.2025.156090

Danting Zheng , Dong Chen , Haosheng Zhao , Lizhi Li , Zhiheng Guo , Zuncheng Zhao , Huiqiu Deng

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引用次数: 0

Abstract

Recently, Fe-Cr-Al alloy is considered one of the most prospective accident-tolerant fuel cladding materials. However, Fe-Cr-Al alloy exposed to fast neutron environments exhibits microstructural features, which leads to material embrittlement, decreases mechanical properties, and affects its service performance. In the present work, molecular dynamics (MD) methods are employed to simulate the irradiation performance of three Fe-Cr-Al alloy systems, namely alloys containing grain boundary (alloy-GB systems), alloys containing Cr-rich α′ phase (alloy-α′ systems), and alloys containing GB and Cr-rich α′ phase (alloy-GB-α′ systems). The GB energies (E_GB) for different symmetric tilted grain boundaries (STGBs) are calculated. The STGBs with high E_GB exhibit more point defects and lower defect annihilation rate than those with low E_GB. And the defect annihilation rate of STGB with low E_GB is high with fewer defects surviving in the bulk. Moreover, the number of vacancies in the bulk is always greater than the number of interstitials. For the alloy-α′ systems containing the Cr-rich α′ phase with the [001] orientation, the increases in temperature and the distance of PKA from the center of the Cr-rich α′ phase (d_PKA-α′) will reduce the degree of irradiation damage. The increases in the size and the Cr content of the Cr-rich α′ phase will enhance the degree of irradiation damage. For the alloy-GB-α′ systems with Σ19(116)[110] GB, the number of final surviving defects is greater than that in the alloy-GB systems, which indicates that the interaction of GB and Cr-rich α′ phase will further increase the degree of irradiation damage. The increases of d_PKA-GB will deepen the degree of irradiation damage when the PKA atom is located in/beyond the Cr-rich α′ phase. Moreover, the dislocations form on the GB for the alloy-GB-α′ systems with Σ19(116)[110]. The appearance of dislocation can significantly affect the defect behaviors in the irradiation damage, which results in a decrease in the number of defects and defect clustering rate.

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对称倾斜晶界和/或富cr α′沉淀对Fe-Cr-Al合金辐照损伤的影响：分子动力学研究

近年来，Fe-Cr-Al合金被认为是最具发展前景的耐事故燃料包壳材料之一。而Fe-Cr-Al合金在快中子环境下表现出微观组织特征，导致材料脆化，力学性能下降，影响其使用性能。本文采用分子动力学方法模拟了含晶界合金（合金-GB体系）、含富cr α′相合金（合金-α′体系）、含GB和富cr α′相合金（合金-GB-α′体系）三种Fe-Cr-Al合金体系的辐照性能。计算了不同对称倾斜晶界（stgb）的晶能。高EGB的stgb比低EGB的stgb有更多的点缺陷和更低的缺陷湮灭率。低EGB的STGB缺陷湮没率高，缺陷存活量少。此外，块状中空缺的数量总是大于间隙的数量。对于含有[001]取向的富cr α′相的合金-α′体系，温度的升高和PKA距富cr α′相中心（dPKA-α′）的距离的增大会减小辐照损伤程度。富Cr α′相的尺寸和Cr含量的增加会增强辐照损伤的程度。对于含有Σ19(116)[110] GB的合金-GB-α′体系，最终存活缺陷数量大于合金-GB体系，说明GB与富cr α′相的相互作用会进一步增加辐照损伤程度。当PKA原子位于富cr α′相内外时，dPKA-GB的增加会使辐照损伤程度加深。此外，含有Σ19（116）的合金-GB-α′体系在GB上形成位错[110]。位错的出现可以显著影响辐照损伤中缺陷的行为，从而降低缺陷数量和缺陷聚类率。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Journal of Nuclear Materials 工程技术-材料科学：综合

CiteScore

5.70

自引率

25.80%

发文量

601

审稿时长

63 days

期刊介绍： The Journal of Nuclear Materials publishes high quality papers in materials research for nuclear applications, primarily fission reactors, fusion reactors, and similar environments including radiation areas of charged particle accelerators. Both original research and critical review papers covering experimental, theoretical, and computational aspects of either fundamental or applied nature are welcome. The breadth of the field is such that a wide range of processes and properties in the field of materials science and engineering is of interest to the readership, spanning atom-scale processes, microstructures, thermodynamics, mechanical properties, physical properties, and corrosion, for example. Topics covered by JNM Fission reactor materials, including fuels, cladding, core structures, pressure vessels, coolant interactions with materials, moderator and control components, fission product behavior. Materials aspects of the entire fuel cycle. Materials aspects of the actinides and their compounds. Performance of nuclear waste materials; materials aspects of the immobilization of wastes. Fusion reactor materials, including first walls, blankets, insulators and magnets. Neutron and charged particle radiation effects in materials, including defects, transmutations, microstructures, phase changes and macroscopic properties. Interaction of plasmas, ion beams, electron beams and electromagnetic radiation with materials relevant to nuclear systems.