Quaternary and ternary interdiffusion experiments were performed on Al-rich α-phase alloys at 793 to 853K. The concentration profiles indicated that the diffusion distance of Cu was shorter than those of Mg and Ag in the solid solutions. The direct and indirect interdiffusion coefficients were positive in the ternary and quaternary alloys (tables 1 and 2). The ratio of the indirect coefficient to the direct one suggested that repulsive interactions existed between Cu and Mg atoms in the alloys. The ratio values of converted interdiffusion coefficients in the quaternary alloys suggested that the interactions between solvent Al atoms and Cu atoms were attractive.

Interdiffusion in α Solid Solution of the Al-Cu-Mg-Ag System. T.Takahashi, K.Hisayuki, T.Yamane, Y.Minamino, T.Hino: Materials Transactions, 2003, 44[11], 2252-7

Table 1

Interdiffusion Coefficients in Al-Cu-Mg-Ag Alloys at 813K