The surface energy of metastable Al3Li precipitates from coarsening kinetics

Small angle X-ray scattering has been used to measure the coarsening kinetics of metastable Al3Li precipitates in a dilute AlLi binary alloy. The results are compared to previous transmission electron microscopy studies of similar alloys. Lifschitz-Slyozov-Wagner coarsening theory was invoked as a means of obtaining the α/Al3Li interfacial energy. However, corrections accounting for effects due to finite volume fractions and limited solubility of Li in the precipitate phase are included. The surface energy was found to be ∼0.005J/m2, significantly less than previously reported. A possible explanation for the discrepancy is discussed.