Davood Azadrooy - School of Metallurgy and Materials Engineering, Iran University of Science and Technology, Narmak, Tehran ۱۶۸۴۴, Iran
Hassan Saghafian - School of Metallurgy and Materials Engineering, Iran University of Science and Technology, Narmak, Tehran ۱۶۸۴۴, Iran

In the current work, the effects of stir casting process parameters on the microstructural features of an in-situ Al 319 based composite reinforced with Fe-based intermetallic phase was studied. Parameters such as stirring temperature, cooling rate, and iron content were investigated to determine how they may influence the morphology, size, and distribution of iron-based intermetallic and eutectic silicon during the process. The optimized microstructures for different Fe contents were determined to be related to those samples processed for 5 minutes stirring at 1200 rpm and at a temperature near the β nucleation temperature and solidified in permanent molds. It was found that the harmful needle-like morphology of the intermetallics was significantly modified into a compact one through melt-shearing at semi-solid region leading to the modification of morphology, aspect ratio, and distribution of Fe-based intermetallics.

Al composites; stir casting; Fe-based intermetallic; β phase modification