The irradiation damage behavior was studied in the nano-grained Ni-Mo-Cr alloy (nano-grained GH3535), which was irradiated by He ion to various dose. The evolution of defects and hardness changes are characterized by transmission electron microscopy and nanoindentation to explore the irradiation tolerance of the nano-grained GH3535 and the coarse-grained GH3535 (annealed GH3535), where the later was chosen as reference material to make comparison with nano-grained GH3535. The results show that though both the average size and number density of He bubbles increase with an increase in the irradiation dose, the smaller volume fraction is found in the nano-grained GH3535 compared with the coarse-grained GH3535 under the same irradiation condition. This indicates that the nano-grained GH3535 possess better irradiation swelling resistance than the coarse-grained GH3535. However, the increase in the hardness of the nano-grained GH3535 is more significant than in the coarse-grained GH3535 under the same irradiation dose. This suggests stronger irradiation-induced hardening of the nano-grained alloy comparing to coarse-grained alloy, due to the impeding effect caused by grain boundaries decorated with He bubbles. This study provides insight into the design of irradiation-tolerant nickel-based alloys for nuclear industry applications.

研究了纳米晶Ni-Mo-Cr合金（纳米晶GH3535）的辐照损伤行为，并用He离子辐照了不同剂量。通过透射电子显微镜和纳米压痕来表征缺陷的演变和硬度变化，以探索纳米级GH3535和粗粒度GH3535（退火GH3535）的辐射耐受性，其中选择后者作为参考材料与纳米级进行比较-GH3535。结果表明，虽然He气泡的平均尺寸和数量密度均随辐照剂量的增加而增加，但在相同辐照条件下，纳米粒GH3535的体积分数要小于粗粒GH3535。这表明纳米粒GH3535比粗粒GH3535具有更好的耐辐射膨胀性。然而，在相同的照射剂量下，纳米粒GH3535的硬度增加比粗粒GH3535的硬度增加更显着。这表明，由于由He气泡装饰的晶界引起的阻碍作用，与粗晶合金相比，纳米晶合金的辐射诱导硬化作用更强。这项研究为核工业应用的耐辐射镍基合金的设计提供了见识。这表明，由于由He气泡装饰的晶界引起的阻碍作用，与粗晶合金相比，纳米晶合金的辐射诱导硬化作用更强。这项研究为核工业应用的耐辐射镍基合金的设计提供了见识。这表明，由于由He气泡装饰的晶界引起的阻碍作用，与粗晶合金相比，纳米晶合金的辐射诱导硬化作用更强。这项研究为核工业应用的耐辐射镍基合金的设计提供了见识。