Fan Cuncai, Shang Zhongxia, Niu Tongjun, Li Jin, Wang Haiyan, Zhang Xinghang
School of Materials Engineering, Purdue University, West Lafayette, IN 47907, USA.
School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN 47907, USA.
Materials (Basel). 2019 Aug 25;12(17):2721. doi: 10.3390/ma12172721.
Nanocrystalline metals have shown enhanced radiation tolerance as grain boundaries serve as effective defect sinks for removing radiation-induced defects. However, the thermal and radiation stability of nanograins are of concerns since radiation may induce grain boundary migration and grain coarsening in nanocrystalline metals when the grain size falls in the range of several to tens of nanometers. In addition, prior in situ radiation studies on nanocrystalline metals have focused primarily on single heavy ion beam radiations, with little consideration of the helium effect on damage evolution. In this work, we utilized in situ single-beam (1 MeV Kr) and dual-beam (1 MeV Kr and 12 keV He) irradiations to investigate the influence of helium on the radiation response and grain coarsening in nanocrystalline Cu at 300 °C. The grain size, orientation, and individual grain boundary character were quantitatively examined before and after irradiations. Statistic results suggest that helium bubbles at grain boundaries and grain interiors may retard the grain coarsening. These findings provide new perspective on the radiation response of nanocrystalline metals.
纳米晶金属已表现出增强的抗辐射能力，因为晶界可作为去除辐射诱导缺陷的有效缺陷阱。然而，纳米晶粒的热稳定性和辐射稳定性令人担忧，因为当晶粒尺寸处于几纳米到几十纳米范围内时，辐射可能会导致纳米晶金属中的晶界迁移和晶粒粗化。此外，先前对纳米晶金属的原位辐射研究主要集中在单重离子束辐射上，很少考虑氦对损伤演化的影响。在这项工作中，我们利用原位单束（1 MeV Kr）和双束（1 MeV Kr和12 keV He）辐照来研究氦对300°C下纳米晶铜的辐射响应和晶粒粗化的影响。在辐照前后对晶粒尺寸、取向和单个晶界特征进行了定量检测。统计结果表明，晶界和晶粒内部的氦泡可能会阻碍晶粒粗化。这些发现为纳米晶金属的辐射响应提供了新的视角。
