Pejman Melali - Department of Materials Engineering , Iran university of Science and Technology, Tehran, P.O. Box: ۱۶۸۴۶, Iran
Mohammad Shahmiri - Department of Materials Engineering , Iran university of Science and Technology, Tehran, P.O. Box: ۱۶۸۴۶, Iran

A hyper eutectic Al-Si alloy is known by its high wear and corrosion resistance and also low thermal expansion coefficient; hence, it used in the automotive industry. Those reasonable advantages are attributed to the primary silicon phase. Therefore, the primary phase morphology plays an important role on the mechanical properties of the final product. On the other hand, the attached coarse silicon primary phase impedes the achievement of significant mechanical properties. Some studies indicate that the addition of Mg element to Al-Si alloy makes the Si primary phase matrix weak and fragile. In this study Mg was added to an A390 hyper eutectic Al-Si alloy. Then, the melt was stirred at 256 and 512 rpm. Results show that a new Mg2si phase is produced in the melt and applying rheocasting methods makes both the Mg2Si morphology and the primary Si phase finer and non-dendritic.

Semi-Solid , In-Situ Composite , Rheocasting , Mg2si , Mechanical Stirring