The effect of grain size on bubble formation and evolution in helium-irradiated Cu-Fe-Ag
The effect of grain size on bubble formation and evolution in helium-irradiated Cu-Fe-Ag
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DOI：
10.1016/j.matchar.2020.110822
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发表时间：
2020-12
影响因子：
4.7
通讯作者：
M. Wurmshuber;D. Frazer;M. Balooch;I. Issa;A. Bachmaier;P. Hosemann;D. Kiener
中科院分区：
文献类型：
--
作者：
M. Wurmshuber;D. Frazer;M. Balooch;I. Issa;A. Bachmaier;P. Hosemann;D. Kiener
纳米结构的金属是一个有前途的候选人，在未来的应用在辐射环境中，如核能设施，由于对辐射损伤的可想象的耐受性。由于氦辐射的存在通常是不可避免的，例如在核聚变设施中，氦对纳米结构材料的性质的影响是迫切感兴趣的。在这项工作中，超细晶（UFG; 100 nm晶粒尺寸）和纳米晶（NC; 20 nm晶粒尺寸）Cu-Fe-Ag样品已被注入各种注量的氦和氦诱导的修改使用原子力显微镜，纳米压痕和透射电子显微镜进行了研究。虽然这些纳米结构材料的耐受性对辐射损伤已被报道较早，我们发现，氦气对溶胀和机械性能的影响是不可忽略的。NC材料中增加的紧密间隔界面的量提供了氦的快速扩散路径，从而促进了辐照早期阶段的气泡成核。然而，对于高注量的氦，NC复合材料中较小的晶粒尺寸和较大数量的成核位点限制了单个气泡的生长，与UFG和常规粗晶材料相比，这对溶胀具有积极影响，并抵消了机械性能的劣化。因此，我们对不混溶的Cu-Fe-Ag纳米复合材料的研究为设计用于辐射环境的新型高辐射耐受材料铺平了道路。
Nanostructured metals are a promising candidate for future applications in irradiative environments, such as nuclear energy facilities, due to a conceivable tolerance against radiation damage. As the presence of helium irradiation is frequently unavoidable, e.g. in nuclear fusion facilities, the effect of helium on the properties of nanostructured materials is of immanent interest. In this work, ultra-fine grained (UFG; 100 nm grain size) and nanocrystalline (NC; 20 nm grain size) Cu-Fe-Ag samples have been implanted with various fluences of helium and were investigated regarding helium-induced modifications using atomic force microscopy, nanoindentation and transmission electron microscopy. While for these nanostructured materials a tolerance against radiation damage has been reported earlier, we find that the influence of helium on swelling and mechanical properties is not negligible. The increased amount of closely spaced interfaces in the NC material provides swift diffusion paths of helium, thereby facilitating bubble nucleation in the early stages of irradiation. For high fluences of helium, however, the smaller grain size and larger amount of nucleation sites in the NC composite restrict the growth of individual bubbles, which has a positive effect on swelling and counteracts mechanical property degradation compared to UFG and conventional coarse-grained materials. As such, our investigations on immiscible Cu-Fe-Ag nanocomposites pave a promising strategy for designing novel highly radiation enduring materials for irradiative environments.