Multi-solute solid solution behavior and its effect on the properties of magnesium alloys

The low-density magnesium (Mg) alloys are attractive for the application in aerospace, transportation and other weight-saving-required fields. The mechanical properties and corrosion properties of Mg alloys are the key-property issues for the wide application. It is surprising to find that the solid solution of alloying elements in the α-Mg phase can have multi-effects on the properties of Mg alloys, e.g., solid solution strengthening, solid solution corrosion-resistance-enhancing, etc. Additionally, the alloy design theory of "solid solution strengthening and ductilizing" proposed by Pan and co-workers has attracted extensive attentions. It is promising that by selected proper multi-alloying-elements (with optimal ratio) solid solutioned in the α-Mg phase, the comprehensive properties of Mg alloys can be synergistically improved. In this work, the solid solution behavior of Mg alloys and the followed solid solution property-enhancing effects were reviewed. The mechanisms proposed recently by researchers for these solid solution property-enhancing behaviors were presented, and the related calculations and predictions were also described. It is shown the demonstrations of the fundamentals for the solid solution property-enhancing of Mg alloys, especially from the atomic inter-reaction aspects, still require elaborated characterization work and calculation work. Additionally, it could be expected that the multi-solute in Mg alloys can bring many possibilities, or, in another saying, "cocktail effects". With understanding the multi-solute interaction behavior and the corresponded solid solution property-enhancing effects, the good balanced high-performance Mg alloys can be developed.