Wei-Ying Chen¹, Meimei Li¹; ¹Argonne National Laboratory

TEM with in-situ ion irradiation has the advantage of capturing the real time microstructural evolution in materials under irradiation. Because of the limitation of electron penetration, thin foil with a thickness less than 200-300 nm needs to be used. The effect of the foil surface on the defect evolution can sometimes be noticeable especially at higher irradiation temperatures. The surface effect, on one hand, makes the in-situ data deviate from the bulk behavior; on the other hand, it provides an opportunity for understanding the interaction of surface with point defects and small defect clusters. In this study, we performed depth-dependent characterization and 3D tomography on nickel and Al0.3CoCrFeNi irradiated with 1 MeV krypton ions at 500°C and 600°C to 1 dpa. The depth dependence of stacking-fault tetrahedral, dislocation loops and voids was quantitatively analyzed to understand the observed heterogeneous spatial distribution of defect clusters.