RADIATION-DAMAGE PROCESS OF VANADIUM AND ITS ALLOYS DURING ELECTRON-IRRADIATION

Microstructural change and the migration energies of point defects in V, V-4Ti-4Cr and oxide dispersion strengthened vanadium were examined by high voltage electron microscopy. II-radiation was performed up to 7.2 dpa at room temperature to 773 K. To protect the specimens from su rface contamination, some specimens were coated with Ti and Cr by the evaporation process. During irradiation of low dose, interstitial-type dislocation loops were initially nucleated and grown. Micro-voids wer e observed in oxide dispersion strengthened vanadium at 773 K. The mig ration energies of interstitials and vacancies were estimated from the number density and the growth rate of the loops, as a function of tem perature. The microstructure change is explained by the effect of the interaction between impurities and solute atoms.