Designing High Corrosion Resistant Peritectic Magnesium Alloys via Sc and Y Addition

With the help of density functional theory (DFT) calculations, Mg-Sc-Y alloys with various Y content were designed and produced. The single-phase Mg-Sc-Y alloys were composed of a typical peritectic microstructure with internal Sc-rich zones surrounded by Y-rich zones. With increasing Y content, the hydrogen evolution rates decreased significantly to 0.13 mL/cm(2)/day and increased slightly afterward. This was attributed to the combined effect of a decrease in the thermodynamic driving force for corrosion, surface layer improvement, and an increase in the number of galvanic couples between the Sc-rich and Y-rich zones.