Effect of rare earth (La, Ce, Nd, Sc) on strength and toughness of 6082 aluminum alloy

Abstract

In this paper, the influence of rare earth elements La, Ce, Nd and Sc on the interface bond strength between stable precipitates (Mg2Si) and matrix aluminum of 6000 series aluminum alloy is studied by first-principles calculation. The calculation shows that when rare earth elements are doped with central site substitution. The interface can be between 0.85 and 0.11 eV/Å2 when the rare earth element replaces Mg atom, which is 22.33% lower than that of the pure interface. The interface energy at the interface of rare earth elements replacing Al atoms is between 0.69 and 0.79 eV/Å2, which is 41.34% lower than that of pure interface. When rare earth elements do random substitution doping except for the central site. When replacing the Al atom, the interface energy of the SAl7 site doping of the Nd element is reduced by 59.28% compared to the pure interface. When replacing the Mg atom, the interface energy of Sc element doped on the SMg1 site is reduced by 50.15% compared to the pure interface. On the whole, the doping interface energy of all sites of different elements decreases compared with 0.13360097 eV/Å2 of the pure interface. This indicates that the doping of rare earth elements can enhance the interface bond strength between the precipitated phase and the matrix, which further enhances the strength and toughness of 6000 series aluminum alloy.