Mechanical and die soldering properties of Al-Si-Mg-Mn cast alloy.

The demand for lightweight alloys for transportation equipment has increased considerably to meet the requirements for improved fuel efficiency and reduced emissions. To reduce the weight of the engine subframe and cross-member, it is essential to develop a cast node component that connects the extrusions and with sufficient strength, toughness and castability including die soldering. Therefore, high strength alloy design and advanced casting process technology are needed to minimise the corresponding casting defects and die soldering. This study examined the die soldering and mechanical properties of Al-Si-Mg-Mn casting alloys prepared by permanent mould casting and evaluated the effects of alloying elements, such as Fe, Mn and Mg, on the tensile and fatigue behaviour. With increasing Fe and Mn contents, the fluidity and shrinkage decrease and die soldering improves. In addition, the increasing Mg content leads to a lower elongation and an improved tensile strength due to the increased precipitation of the Mg2Si phase. The high cycle fatigue lives show a similar tendency in the case of the R = −1 wave form with increasing total contents of Fe and Mn, whereas the fatigue strength increases with increasing Mg content. [ABSTRACT FROM AUTHOR]