Microstructural Studies of 2024-9wt.%Al4Sr and 2024-16wt.%Al4Sr Metal Matrix Composites (MMCs)

This study was undertaken to study the microstructure of 2024-9wt.%Al4Sr and 2024-16wt.%Al4Sr Metal Matrix Composites (MMCs). Microstructural Stady Was Carried Out by the use of optical microscope and scanning electron microscope (SEM). Typical microstructure of 2024 alloy consists of α-Al and Cu-rich intermetallics (mainly θ phase) segregated at the grain boundaries. It has been forund that The presence of 4 wt.% Sr (9 wt.% Al4Sr) added primary needle-like Al4Sr intermetallics to the system. Moreover, the matrix includes eutectic α-Al/Al4Sr network. As the amount of Sr in the system increases to 7 wt.% (16 wt.% Al4Sr), the eutectic network becomes negligible; however, the primary needle-like particles coarsen (average size of 250 μm) which are known as main sites for stress concentration. It is interesting to note that Sr has marginal effect on the morphology and distribution mode of Cu-rich intermetallics in the matrix.

کلیدواژه ها:

Metal matrix composite (MMC) ، Microstructure ، Intermetallics