THE EFFECT OF MANGANESE ON Fe-RICH INTERMETALLIC PHASES IN PROGRESSIVE SECONDARY AlSi7Mg0.6 ALLOY

The contribution describes the major problem with the secondary (recycled) alloys as the presence of unwanted elements due to the remelting of Al-scrap negatively affecting the quality of AlSi7Mg0.6 cast alloy. Iron is the most harmful impurity in the secondary Al-Si alloys, leading to the formation of β-Fe-rich (Al₅FeSi) intermetallic phases that promotes forming of casting defects such as porosity and shrinkage by its needle-like shape. Suitable neutralizer alloying elements, such as Mn, influence the formation of Fe-needle-like phases and lead to the formation of less harmful Mn-containing α-Fe-rich phases. To optimize the morphology and properties of alloys, it is necessary to study the effects of individual alloying elements. Therefore, this study is focused on the effect of Mn addition on Fe-rich intermetallic phases and casting defects, thus the evaluation of its shape and distribution in AlSi7Mg0.6 secondary alloy.