Al-Mn alloys for electrical applications: A review

Development of lightweight Al alloys with high electrical conductivities, tensile properties and low cost are highly needed for market expansion of battery-powered electric vehicles (BEVs) in the automotive industry and durable transmission lines in the electric power industry (EPI). As an alloying element, Mn has a low maximum solubility of 1.25 wt% in Al under equilibrium solidification and forms Al6Mn dispersoid as a strengthening phase. Manganese (Mn) is usually introduced into wrought Al alloys such as AA3xxx series, because of its capability of improving uniform deformation and strengths of pure aluminum. In this article, the influence of Mn on the electrical and mechanical properties of Al alloys is discussed. The microstructure features and relevant electrical conductivities of Mn-containing Al alloys are reviewed. The strengthening mechanisms of Al alloys are overviewed. The cooling rate-dependent mechanical properties of Al-Mn alloys are presented.