Grain growth stagnation and texture development in an irradiated thermally stabilized nanocrystalline alloy
Grain growth stagnation and texture development in an irradiated thermally stabilized nanocrystalline alloy
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DOI：
10.1063/1.5118943
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发表时间：
2019-11
影响因子：
3.2
通讯作者：
Prince S. Singh;Di Chen;L. Shao;Y. Picard;M. D. de Boer
中科院分区：
文献类型：
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作者：
Prince S. Singh;Di Chen;L. Shao;Y. Picard;M. D. de Boer
纳米晶金属在核材料应用中具有强烈的兴趣，因为它们的晶界可以作为点缺陷的有效复合位点。因此，它们可能能够以最小的损害承受高剂量。在这里，我们研究纳米晶NiW，一种热稳定的纳米晶材料，初始晶粒直径为6 nm。我们发现，当受到中等剂量的Ni+自离子辐照时，晶粒生长与纳米晶Ni的晶粒生长没有区别。然而，一旦晶粒以每原子10次位移（dpa）生长到32 nm的平均直径，这种辐照诱导的晶粒生长（IIGG）停滞到100 dpa。这种停滞是以前的模型所没有预测到的。IIGG停滞被发现与微观结构的演变，其中一个初始的弱纤维织构转化为双轴织构与低能量晶界的同时增加，以稳定在较高的辐照doses.Nanocrystalline金属的微观结构的强烈兴趣，在核材料的应用，因为它们的晶界可以作为点缺陷的有效重组网站。因此，它们可能能够承受高剂量而损害最小。在这里，我们研究纳米晶NiW，一种热稳定的纳米晶材料，初始晶粒直径为6 nm。我们发现，当受到中等剂量的Ni+自离子辐照时，晶粒生长与纳米晶Ni的晶粒生长没有区别。然而，一旦晶粒以每原子10次位移（dpa）生长到32 nm的平均直径，这种辐照诱导的晶粒生长（IIGG）停滞到100 dpa。这种停滞是以前的模型所没有预测到的。IIGG停滞被发现与微观结构的演变，其中一个初始的弱纤维织构转变成双轴织构与低能量晶界的同时增加，以稳定在较高的辐照剂量的微观结构。
Nanocrystalline metals are of strong interest in nuclear material applications because their grain boundaries may act as effective recombination sites for point defects. Consequently, they may be able to sustain high doses with minimal damage. Here, we investigate nanocrystalline NiW, a thermally stabilized nanocrystalline material with an initial grain diameter of 6 nm. We find that grain growth when subject to moderate doses of Ni+ self-ion irradiation is not distinguishable from that of nanocrystalline Ni. However, once the grains grow to an average diameter of 32 nm at 10 displacements per atom (dpa), this irradiation-induced grain growth (IIGG) stagnates up to 100 dpa. Such stagnation is not predicted by previous models. IIGG stagnation is found to correlate with microstructural evolution, where an initial weak fiber texture transforms into a biaxial texture with a concurrent increase in low energy grain boundaries acting to stabilize the microstructure at higher irradiation doses.Nanocrystalline metals are of strong interest in nuclear material applications because their grain boundaries may act as effective recombination sites for point defects. Consequently, they may be able to sustain high doses with minimal damage. Here, we investigate nanocrystalline NiW, a thermally stabilized nanocrystalline material with an initial grain diameter of 6 nm. We find that grain growth when subject to moderate doses of Ni+ self-ion irradiation is not distinguishable from that of nanocrystalline Ni. However, once the grains grow to an average diameter of 32 nm at 10 displacements per atom (dpa), this irradiation-induced grain growth (IIGG) stagnates up to 100 dpa. Such stagnation is not predicted by previous models. IIGG stagnation is found to correlate with microstructural evolution, where an initial weak fiber texture transforms into a biaxial texture with a concurrent increase in low energy grain boundaries acting to stabilize the microstructure at higher irradiation doses.