The Interface Between δ′ and Matrix in an 8090 Al-Li Alloy Studies by SAXS

A small angle X-ray scattering (SAXS) techniques has been used to characterize the interfaces between the δ′ phase and matrix in and 8090 Al-Li alloy aged at 160°C for several times. The results showed that a transition interfacial layer exists between the δ′ phase and matrix in the earlier stage of aging, which disappears in the later stage of aging. The existence of a transition interfacial layer indicated that the phase precipitates by spinodal decomposition. This mechanism is thought to be the cause of the deviation of δ′ phase coarsening from the LSW coarsening rate law.