عنوان	Effect of Gadolinium Addition on the Thermal, Microstructural, Mechanical, and Tribological Properties of Recycled Al-0.5Fe-0.5Si alloy
نوع پژوهش	مقاله‌ی منتشر شده در نشریه
کلیدواژه‌ها	Recycled Al-Fe-Si alloy, Gadolinium, Grain refinement, Intermetallic phases, Mechanical properties, Wear resistance
چکیده	This study investigates the effect of gadolinium (0.1-0.8 wt.%) on the solidification behaviour, microstructure, mechanical properties, and tribological performance of a recycled Al-0.5Fe-0.5Si alloy. Thermal analysis reveals that Gd addition transforms the solidification path from two phases (α-Al and Al₃Fe) in the base alloy to four phases, including the newly formed Al₃Gd and Al₃(Fe,Gd,Si). XRD and SEM-EDS jointly confirm the precipitation of these Gd-containing intermetallics. Microstructural analysis reveals progressive grain refinement, reaching approximately a 60% reduction at 0.8 wt.% Gd — consistent with extended dendrite coherency time. Mechanical testing demonstrates significant improvements: +14% in ultimate tensile strength, +29% in hardness, with only a moderate reduction in ductility. Tribological performance is also enhanced, with a 45% reduction in coefficient of friction and a 31% decrease in wear rate. These enhancements are attributed to grain refinement and precipitation of hard Gd-intermetallics, which hinder dislocation motion and reduce adhesive wear.
پژوهشگران	سعید فراهانی (نفر سوم)، حمیدرضا قندور (نفر پنجم)، علی محمد الطمیمی (نفر اول)، توتی اسما ابوبکر (نفر دوم)، محمد ایوب سولونگ (نفر چهارم)