Abstract: The calculation of electronic structure of γ'-Ni_3Al phase with or without Mg and W by the Recursion and LCAO methods clarified that Mg and W atoms lose their outer electrons par- tially after they entered γ'-Ni_3Al.It causes the reduction of the radii of the atoms.So it is preferable for Mg atom to enter γ'-phase by the substitution.The interaction between Mg and γ'-phase matrix may be strengthened and a more stable structure of γ'-phase may be formed while Mg and W entered γ'-Ni_3Al simultaneously.

Key words: superalloy, Ni_3Al, electronic structure, Mg alloying