Combined Small Angle X-Ray Scattering and Transmission Electron Microscopy Studies of Al-Li Alloys

摘要

Combined small angle x-ray scattering (SAXS) and transmission electron microscopy (TEM) studies have been performed on two binary Al-Li alloys subjected to different pre-aging treatments. Both the SAXS and TEM data indicate that delta (Al sub 3 Li) in samples of the two alloys directly quenched to the aging temperature is larger in size than in samples quenched to below room temperature prior to aging. SAXS data indicate an initial rise in scattering center size in Al-9.4 at. % Li, or in the TEM studies of delta' in both alloys. It is considered that these observations are evidence that the initial rise in the SAXS data in Al-9.4 at. % Li alloys is due to a phenomenon other than delta' precipitation. The possibility of matrix spinodal decomposition in this alloy is one explanation. (ERA citation 10:046721)