First Principles Calculations of Solute Sweeping and Stacking Faults in Mg-Zn-Y Alloy

Abstract

The formation mechanism of the long-period stacking-ordered (LPSO) structure of a Mg-Zn-Y alloy was investigated through energy assessments using first-principles calculations. The solute atoms are swept out from stacking fault regions because of their repulsive interaction with precipitated L1₂ clusters. The swept-out solute atoms are condensed a few layers away from the stacking-fault regions and accelerate the introduction of other stacking faults. A new scenario in the formation of the LPSO structure is proposed.