Microstructure characteristics of a hypereutectic Al-Si alloy manufactured by rapid solidification/powder metallurgy process

The microstructure and phase morphology of a rapid solidification/ powder metallurgy Al-Si-Fe-Cu-Mg alloy with high silicon content were reported. A large amount of fine particle phases were uniformly distributed in the aluminum matrix as depicted by the microstructure of the extruded alloy under scanning electron microscopy (SEM). The shape, dimension, fine strips fragmented trace etc. offered a direct evidence of phase transformation. The phase was formed in the course of rapid solidification and the dimples indicated a representative freezing shrinkage characterstic.