Comprehensive first-principles evaluation of solute segregation and embrittlement at the magnesium grain boundary

Understanding grain boundary (GB) solute segregation in magnesium (Mg) alloys and its influence on embrittlement is essential for improving intergranular fracture resistance; however, systematic studies are still limited. In this study, first-principles calculations combined with the Rice-Wang model evaluated the segregation behavior of 68 solutes at the ∑13[0001] (75¯2¯0) GB and their embrittlement tendencies along several fracture paths, with effective contributions weighted by equilibrium solubilities at 773 K. Integrating segregation, solubility and fracture-path effects identifies zirconium and most rare earth elements as promising GB-strengthening solutes, guiding GB engineering and data-driven prediction.