Influence of recycling aluminum on the quasi-static and cyclic material behavior of AlSi7Mg0.3

Automotive industry and mechanical engineering strive to drastically reduce the carbon footprint of their products. This is getting even more important since the usage of light weight metals like aluminum increases for light and efficient components. Nevertheless nowadays, cast aluminum products suffer from a lack of aluminum alloys that bear higher fraction of recycling alloys since their availability is crucial. The usage of recycling aluminum in gravity die casting processes could offer a high potential for the reduction of CO2emissions but the effect of increasing accompanying elements like Cu, Zn or Fe in the recycled alloy on the cyclic material behavior is not investigated until now. Within the Fraunhofer internal research project "FutureCarProduction" the effects of recycling or secondary aluminum alloys on the casting process as well as the fatigue and crash behavior of car body components are investigated. The aim is to find thebest combination between manufacturing efficiency and durability in relation to the alloy’s potential to reduce the carbon footprint and further negative emissions during the product life cycle. Based on the alloy AlSi7Mg0.3 used in gravity die casting components for car body parts three different configurations one as primary alloy and two with accompanying elements were cast and investigated by stress-controlled tests. It could be shown that additions of Fe and Zn e.g. lead to an increaseinthe cyclic and quasistatic material behavior whereas the ductility was reduced.