Magnesium alloys that are less dependent on Rare Earths

Rare Earths are added to many alloy compositions to improve performance. Many of these Rare Earths are strategically important elements, and dependent industries are likely to be subject to constrained supply due to supply limitations in the producing countries.

Despite their importance in the manufacture of many of these alloys, there is no fundamental understanding of how Rare Earth elements work in magnesium alloys. One possibility is that their electronic structure is a key factor – as these elements have accessible unfilled f-orbitals.

Alternatively, it may simply be the size of the atom that is important, changing the interactions between alloy components and grain boundaries. In the latter case, it may be possible to select elements from elsewhere in the periodic table that we would expect to impart the same benefits at a lower cost and strategic supply risk.

One objective of the DARE project was to predict a possible alloy formulation where the Rare Earth is replaced by an alternative element. This was done using the toolbox of techniques employed for the other alloys, but extending this with our expertise in modelling electronic structures of metals, which we correlated with electron microscopy and X-ray diffraction techniques to answer questions about the role of the elements electronic properties in microstructure formation.