Interaction of elements in dilute Mg alloys: a DFT and machine learning study

Abstract

The solution behavior of alloying elements is crucial for the design of Mg alloys. The plasticity, strength and corrosion resistance of Mg alloys can be tailored by alloying elements in solid solution in the primary Mg phase. In this work, the interaction and solution behavior of 24 alloying elements in Mg alloys, including 24 binary systems and 88 ternary systems, was studied. Features characterizing the interactions of solute elements in the primary Mg phase, including atomic substitutional sites, volume difference, c/a ratio and formation energy, of these alloys were calculated by first principles. Relations between the interaction features and the alloying elements’ characteristics were constructed based on machine learning methods, in which strong correlations were observed. Additionally, the electronic and atomic origin of the interaction features in solid solution ternary Mg alloys were analyzed. This work provides new insights into the design of high-performance multicomponent Mg alloys, as well as the construction of atomic models for other alloys.