Ion irradiation-induced the radiation hardening in Fe and Fe-0.3Si alloys

Abstract

Depth profile of Helium irradiation effects in reactor pressure vessel (RPV) model material is identified using a nano-indentation technique in order to develop a new methodology to clarify the solute-vacancy interaction. 2 MeV He ion was irradiated in pure iron at room temperature with and without an energy degrator. The indentation hardness was measured by nanoindentation changing the load at 9 levels. Hardening in irradiated materials was clearly observed in all indentation loads as well as the well-known indentation size effect. It was interesting that the significant increase of hardness was recognized at 0.8 μm depth, which is corresponding to the obstacle of deformation at 3˜4 μm depth, that would be the cause of helium implantation. Furthermore, dose effects on 3MeV Si irradiated RPV model materials were confirmed.