Long-time annealing at ambient temperature of a mildly treated commercial AI-Li alloy

Abstract Mildly treated samples of a commercial Al-Li alloy have been studied, after ageing at ambient temperature for different times over a period of nearly a year, by small-angle X-ray scattering. It was found that the structure of the alloy changed over time and that precipitate particles increased in dimension. A two-step particle growth rate has been observed and attributed to two different mechanisms. First, nucleation events are taking place whereas the second slower step is attributable to coarsening. During the latter stage the Lifshitz-Slyozov law of R 3 against t was followed.