Element doping improving mechanical properties of β' phase in Al-Mg-Si alloy

The effect of element doping on the mechanical properties of beta'-Mg9Si5 phase in Al-Mg-Si alloys are investigated using density-functional calculations. The results reveal that Mg17Si10Ge exhibits the highest degree of stability, attributed to its lower formation enthalpies. Doping of Ge and Zn elements may lead to a reduction in the material's hardness. Conversely, the addition of Al and Zn elements can significantly enhance the toughness and ductility of Mg17Si10X. The electron orbits of Si atoms are the primary influencing factor. The strength-ductility of these materials can be finely tuned by altering the charge transfer around the doping atoms.