Influence on the Quality of Secondary Aluminum Alloy Casts by Mn Addition

Abstract

The quality of aluminum casts is necessary in order to reach sufficient properties required for application. The decreasing in the properties of aluminum cast mainly related with microstructure, especially with size and morphology of second phases. One of such second phases in aluminum alloys are the β-phases. These phases are unwonted mainly because of the decreasing of mechanical properties. The contribution is deal with influence of addition of Mn to affecting the formation of β-phases in the AlSi7Mg0.3 and AlSi7Mg0.6 cast alloys. These materials are used for application especially automotive industry. The results shows, that addition of Mn is not sufficient for affecting of formation of the Fe-rich phases in AlSi7Mg0.6 cat alloys, but in the AlSi7Mg0.3 this addition lead to changes in formation of Fe-rich intermetallic phases.

The Influence of Foundry Scrap Returns on Chemical Composition and Microstructure Development of AlSi9Cu3 Alloy

“…Secondly, many impurities are introduced into the melt with secondary aluminium. Iron is one of the main elements that form iron-rich intermetallic phases, including the less harmful α-Al 15 (Mn,Fe) 3 Si 2 phase with "Chinese script" morphology and harmful β-Al 5 FeSi needles [11]. To avoid the formation of β-Al 5 FeSi, different methods can be used: melt superheating, higher cooling rates, and chemical modification.…”