Self-healing of deformation damage in underaged Al–Cu–Mg alloys

The generation and evolution of open volume defects in underaged and T3 Al–Cu–Mg alloy is studied with positron annihilation spectroscopy. During room temperature ageing the positron lifetime in plastically deformed, underaged material approaches the saturation lifetime of the undeformed material. Doppler-broadening results indicate that this behaviour can be attributed to diffusion and clustering of retained solute Cu atoms at the deformation defects, a process of relevance for the introduction of a self-healing mechanism in age-hardenable aluminium alloys.