On the age hardening response of aluminum containing magnesium sheets with zinc or manganese (AZ- and AM series alloys)

Abstract

A higher content of Al in Mg alloys leads to the formation of the precipitation hardening intermetallic compound Mg17Al12. However, the rollability and the resulting ductility and formability of sheets of such alloys are reduced with increasing Al content. In this study, Mg alloys of the AZ- and AM- series were used to investigate the impact of the Al content on the rollability, the resulting sheet properties and the ability to precipitation strengthen the sheets subsequent to the rolling process. Alloys with 6 and 8 wt% content of Al were used. The higher content of aluminum leads to a decrease of rollability at a given rolling schedule as well as a decrease of the ductility of the sheets after rolling and annealing. Alloys of the AM series perform more advantageously compared to AZ series alloys. However, Mn limits the ability to precipitation strengthening. The ability to balance both properties is discussed.