A Peek into Next-Generation Magnesium Alloys

The demand for magnesium (Mg) usage continues to increase, driven by new consumer products (such as portable electronics) and the need for light weighting (in the case of transportation). The prospects for Mg-alloys remain greatest in the context of aerospace applications, however the balance of properties in the existing portfolio of Mg-based alloys available has not been adequate to allow a wholesale transition to Mg components. Undoubtedly Mg-alloys have been utilised on aircraft the past, however in several historical cases poor service performance has led to materials substitution. To this end, Mg-alloys remain somewhat of a novelty in critical applications, in spite of high demand and growing production (the latter principally associated with increased utilisation of cast components). When considering alloy systems more generally, several key issues regarding Mg-alloys include at least the following: limited formability, moderate maximum specific strength, and the practical and pragmatic aspect of very high susceptibility to corrosion and limited strategies for corrosion control. Herein, a number of new alloy concepts are presented, including their rationalisation, and their performance. The examples are selected on the basis that they represent a design directed approach.