Quaternary interdiffusion experiments were performed on Al-rich alloys at 755 to 833K. The concentration profiles indicated that the diffusion distance of Cu was shorter than those of Zn or Mg in the solid solutions. The direct interdiffusion coefficients were all positive and the indirect coefficients were all negative. The impurity diffusion of Cu in Al-3.37Zn-2.75Mg could be described by:

D (cm2/s) = 5.7 x 10-1 exp[-132(kJ/mol)/RT]

T.Takahashi, Y.Minamino, K.Hirao, T.Yamane: Materials Transactions, 1999, 40[9], 997-1004