Effect of micro-alloying solute addition on the stacking fault energy of Al–Cu alloys: A computational and experimental approach

Abstract

Present study reports the individual and synergistic effect of Mn and Zr solute addition to the stacking fault energy (SFE) of Al–Cu alloys through first principle-based density functional theory (DFT) calculations and experimental x-ray diffraction line profile analysis (XRDLPA). DFT calculations suggest that while Mn addition enhances SFE for Al–Cu–Mn alloys, Zr addition significantly lowers it for Al–Cu–Zr alloys with their co-addition in Al–Cu–Mn–Zr alloys producing an intermediate SFE. XRDLPA of these alloys in cold-rolled conditions validates the trend obtained from the theoretical calculations with consistency and absolute values to a satisfactory extent. Uniaxial tensile testing finally confirms SFE variation from the mechanical properties, especially the ductility of the cold-rolled alloys, which corroborates well with the variation in their strain hardening response as well.