Morphology and kinetics of microstructural evolution in a Cu-Be alloy irradiated with Cu + ions

Abstract

The morphology and kinetics of microstructural evolution in a Cu-1.35 at% Be alloy subjected to 300 keV Cu + ion irradiation have been investigated by means of transmission electron microscopy (TEM). The irradiation produces precipitates of an ordered (B2) phase γ, even when the alloy is thermally undersaturated. The observed evolution of the precipitate size is a result of two processes, namely radiation-induced growth and dissolution. The following parameters have been derived from the growth kinetics: (a) the diffusion coefficient of Be in Cu and its dependence on temperature and defect production rate K o ; (b) the dissolution rate of the precipitates and (c) the sink strength for point defect annihilation. This is about one order of magnitude larger than the estimated strength of the sinks visible by TEM.