The effects of He implantation on the thermal stability of Cu-Al precipitates in aluminum

In this contribution we report on the effects of He on the formation and th ermal evolution of Cu-Al precipitates produced after Cu+ and He+ ion implan tation in pure Al foils, The profiles of Cu and He were measured via Ruther ford Backscattering (RBS) and Elastic Recoil Detection Analysis (ERDA) tech niques, respectively, and the precipitate and bubble morphology were invest igated by TEM. After thermal annealing, we observe a retardation of the Cu- Al precipitates coarsening and a Cu redistribution governed by the presence of He bubbles. Our results are discussed in terms of an overpressurized bu bble system, which reduces the local vacancy concentration and affects the diffusional process, (C) 2000 Elsevier Science B.V. All rights reserved.