As an outstanding material for moderator and reflector, graphite is broadly applied in nuclear reactors. Irradiation will change the pore structure and content, which is intimately related to the properties of graphite. However, the irradiation effect of nuclear graphite on pores requires a more profound understanding, especially the evolution on a three-dimensional(3D) view. In this work, FIB-SEM tomography intuitively reveal the pore structure and porosity evolution of ion irradiated graphite grades IG110 in a 3D view, which was irradiated with 30 MeV Ni⁵⁺ ion at 400 °C. Besides, the quantitative statistic of porosity indicates a negative correlation between porosity with the ion irradiation damage and confirms the consistency of ion deposition sites and irradiation damage peak. Moreover, individual microcracks of the different ion irradiated depths and virgin graphite are extracted and displayed in various 3D perspectives, which exhibit a much more complex morphology than lenticular structure and demonstrates the closed trend of the microcracks under irradiation. Through the display of 3D pore structure and quantitative statistics of porosity, aims to provide a further understanding of ion irradiation behavior of nuclear graphite.

石墨作为一种优良的减速器和反射器材料，在核反应堆中得到了广泛的应用。辐照会改变孔隙结构和含量，这与石墨的性质密切相关。然而，核石墨对孔隙的辐照效应需要更深入的理解，尤其是在三维（3D）视图上的演化。在这项工作中，FIB-SEM 断层扫描在 3D 视图中直观地揭示了离子辐照石墨等级 IG110 的孔结构和孔隙度演变，该石墨用 30 MeV Ni ⁵⁺辐照离子在 400 °C。此外，孔隙率的定量统计表明孔隙率与离子辐照损伤呈负相关，证实了离子沉积位点与辐照损伤峰的一致性。此外，不同离子辐照深度和原始石墨的单个微裂纹被提取并以各种3D视角显示，其形态比透镜状结构复杂得多，并表明微裂纹在辐照下的闭合趋势。通过3D孔隙结构的显示和孔隙率的定量统计，旨在进一步了解核石墨的离子辐照行为。