One of the greatest challenges facing the recycling of Al-based alloys is handling Fe incorporation. The formation of Fe-rich phases has negative impacts on the mechanical behavior and may limit the usage of recycled alloys. In this context, V addition is regarded as a potential solution since it can inhibit the formation of such phases. However, the microstructure evolution of V-modified Al-based alloys is not fully understood, especially when different solidification cooling regimes are considered. Thus, this work investigates the microstructure and tensile properties of an Al-7Si-1Fe [wt.%] alloy modified with a 0.5 wt.%V addition. Directionally solidified samples were produced and subjected to microstructure analysis and tensile tests. It was found that the addition of V reduces the fraction of β-AlFeSi particles because of the formation of new V-rich phases. This was determinant to improve the tensile properties for faster cooling conditions during solidification. For moderate and slow cooling regimes, however, the V-containing alloy had a less favorable mechanical behavior due to the formation of larger β-AlFeSi particles. Finally, quantitative relationships are proposed for the prediction of tensile properties from microstructural parameters using multiple linear regression analysis.

Al-based alloys are often selected for use in various engineering applications as well as in the aircraft and aerospace industry. The improvement of their performances under severe conditions have required the use of alloying elements. In the present work, Be is added to the eutectic Al-33 wt.%Cu alloy with a view to investigating the resulting effects on microstructural features and hardness. A directional solidification technique is used, yielding a wide range of solidification cooling rates. This permits microstructural features to be investigated with emphasis on the role of Be on the eutectic morphology. The directionally solidified microstructures are formed by eutectic colonies for the Al-33 wt.%Cu alloy, however, with additions of both 0.05 and 0.5 wt.% Be, the original cell-like morphology is transformed into a trefoil-like morphology. This together with the α-Al dendritic pattern characterize the microstructure of the Al-33Cu-Be alloys examined. Solidification growth laws are experimentally derived relating dendritic and eutectic colony spacings to solidification cooling rates and growth rates. The length scale of such spacings is shown not to affect the Vickers hardness of the Al-33Cu-Be alloys examined; however, the additions of Be are shown to improve the brittle behavior of the Al-33 wt.%Cu alloy.