Correlation between mechanical properties and amount of dendritic α-Al phase in as-cast near-eutectic Al–11.6% Si alloys modified with strontium

The amount of dendritic α-Al phase with varying Sr content in near-eutectic Al–11.6% Si alloy was measured by quantitative metallography analysis software and the correlation of mechanical properties of fully modified alloy with the amount of dendritic α-Al is discussed. Addition of Sr in Al–Si alloys results in a considerable increase of the amount of α-Al. Mechanical properties of the fully modified alloy are linearly related to the volume fraction of dendritic α-Al, which plays a key role in improving the mechanical properties of near-eutectic Al–Si alloys.