The pores evolution in 3D view of nuclear graphite under ion beam irradiation

Abstract

• FIB-SEM tomography show off the pores evolution of ion irradiated nuclear graphite in 3D view. • 3D reconstruction for the quantitative statistic of porosity. • Typical microcracks are extracted and displayed in 3D perspectives. • Reveal the closure of microcracks caused by ion irradiation on a 3D scale. 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 Ni 5+ 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.