Abinitio study of the effect of solute atoms Zn and Y on stacking faults in Mg solid solution

Abstract

The effects of solute atoms Zn and Y on I1 and I2 stacking faults in Mg–Y–Zn solid solution have been studied within framework of density functional theory using Vienna Ab initio Simulation Package (VASP). The calculated results show that the addition of Y or Zn exhibit the opposite effect on the stable and unstable stacking fault energies, and the simultaneous addition of Y and Zn decreases the stable and unstable stacking fault energies dramatically. Then it is further found that in Mg–Y–Zn solid solution the extended dislocation configuration tends to be stabilized and the dissociation of dislocation into partials would happen more easily, and the ductility could also be obviously improved. The electronic structures reveal that the significant reduction of SFEs originates from the stronger interaction between slip planes due to the formation of covalent bonds.