Achieving exceptional radiation tolerance with crystalline-amorphous nanocrystalline structures
Achieving exceptional radiation tolerance with crystalline-amorphous nanocrystalline structures
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DOI：
10.1016/j.actamat.2019.12.058
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发表时间：
2020-03
期刊：
影响因子：
9.4
通讯作者：
Miaomiao Jin;P. Cao;M. Short
中科院分区：
文献类型：
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作者：
Miaomiao Jin;P. Cao;M. Short
具有非晶间膜（AIF）的纳米结构材料已经表现出上级的强度和延展性。它们的辐射耐受性预计将是高的，因为大部分的界面体积有效地下沉辐射引起的缺陷。在这里，我们演示了如何晶体-非晶系统（纳米晶Cu与Zr掺杂的AIFs）响应连续照射与分子动力学模拟。我们提出了一个扩散模型，很好地表征级联驱动的混合过程，并揭示了Zr分布的扩展与损伤水平呈线性关系。异常的抗辐射性归因于界面作为可持续的缺陷汇，Zr混合到体中，以提高局部缺陷湮灭由于溶质间隙拖曳，和Zr阻碍辐射增强的晶粒生长，通过抑制AIF从迁移和保持界面刚度。这些发现表明，AIF工程系统有望成为高度耐辐射的材料，具有强大的结构稳定性和辐射损伤下的自我修复能力。
Nanostructured materials with amorphous intergranular films (AIFs) have demonstrated superior strength and ductility. Their radiation tolerance is expected to be high as the large fraction of interfacial volume efficiently sinks radiation-induced defects. Here we demonstrate how a crystalline-amorphous system (nanocrystalline Cu with Zr-doped AIFs) responds to continuous irradiation with molecular dynamics simulations. We propose a diffusion model that well characterizes the cascade-driven mixing process, and reveal that the spread of Zr distribution scales linearly with the damage level. The exceptional radiation resistance is attributed to the interfaces acting as sustainable defect sinks, Zr mixing into the bulk to enhance local defect annihilation due to solute-interstitial dragging, and Zr impeding radiation-enhanced grain growth by restraining AIFs from migration and maintaining interface stiffness. These findings suggest that AIF-engineered systems hold promise as highly radiation-tolerant materials with strong structural stability and self-healing capability under radiation damage.