Microstructure evolution of alumina borate whisker reinforced AA2024 composite after T6 treatment

The microstructure of alumina borate whisker reinforced AA2024 composite, subjected to different aging states, was studied by transmission electron microscopy. The characteristics of interfacial phases and the morphology of precipitates in the matrix were investigated. The morphology and distribution of precipitates near the interface between the whiskers and matrix in the composite were also studied. The results indicated that two typical interfacial phases existed at the interface between the whisker and the matrix. These two interfacial phases were different in composition and shape. The morphology and distribution of precipitates were also different near the interface with the different interfacial phases and the geometric features of whisker surface. The precipitates in the matrix were also investigated.