The influence of Mn on the microstructure and mechanical properties of the Al–5Mg–Mn alloy solidified under near-rapid cooling

A research was carried out to investigate the microstructures and mechanical properties of high Mn containing Al–5Mg–Mn alloys cast under near-rapid cooling. The results indicated that the mechanical properties of the hot bands and cold rolled sheets were remarkably improved with Mn content increasing to 1.6 wt%. The near-rapid cooling process greatly refined the intermetallic constituents. The intermetallic Al 6 (Fe,Mn) particles found in the hot bands were rare and small when the content of Mn was hypoeutectic. In the samples with higher Fe and Si content, a large amount of Al 6 (Fe,Mn) and Mg 2 Si particles remained in the hot bands. But the hot bands still showed better mechanical properties due to the refinement of the intermetallic constituents by the near-rapid cooling process. The results were of commercial interest to the production of AA5083 alloy via continuous strip casting process.