Evolution of iron based intermetallic phases in Al-7wt%Si hypoeutectic alloy

Abstract

This study has methodically characterized the iron based intermetallic phases evolving during solidification of Al-Si binary alloys as a function of solidification cooling rate and and composition of Fe in the alloys. Contrary to the predictions of the evolution of only the β (Al, Si, Fe) in these alloys by all commercial thermodynamic phase diagram simulation tools, the dominant phases were mostly the α (Al, Si, Fe) intermetallic phases and significantly vary in nature and type with the process parameters. The results from this study will further enable better design of the Al-Si alloys with an in-depth understanding of the evolution of the intermetallic phases and methodologies to prevent or modify the same in the final cast components.