Cooperative growth of dislocation loops and voids under electron irradiation

Abstract

Electron irradiation damage studies have been performed on thin foils of pure copper in a high voltage electron microscope. The effects of foil thickness, electron flux, temperature, and initial dislocation density on the formation of voids were studied. Kinetics of void nucleation and growth were interpreted in terms of dislocation biasing of the vacancy and interstitial concentrations and the capture ratio. The void density initially increased as a function of dislocation density, while void size decreased. As a result, swelling at first was increased and subsequently decreased with increasing dislocation density. It was thus confirmed that the presence of dislocations is a necessary condition for void formation.