Effects of Helium Implantation and Subsequent Electron Irradiation on Microstructures of Fe-11wt.% Cr Model Alloy

Helium effects on dislocation and cavity formation of Fe-11 wt.% Cr model alloy are investigated. Single-beam (electron) and dual-beam (He^+/e^-) irradiations are performed at 350^\circ\!C and 400^\circ\!C using an ultra-high voltage electron microscope combined with ion accelerators. In-situ observation shows that the growth rate of dislocation loops is reduced in the helium pre-injected specimen. The mean size of cavities decreased in the helium pre-injected specimen. The possible mechanisms are discussed.