Abstract
The effect of third elements such as Mn, Cr, Mg and Si on the rate of diffusion of Cu into the molten Al was studied. The rate of diffusion of Cu plus Zn, Fe plus Ni, or Si Plus Mg, when each couple is added simultaneously into the molten Al, was compared with that of each element when added separately. The equjplmerlt for the diffusion process applied to the present experiment was exactly the same as that used in the previous study. From the result of such investigation, it was conc uded that:
(1) The rate of Cu diffusion is pronouncedly retarded by the presence of Si in the molten Al, but selightly lowered or substantially unaffected by the presence of the other elements.
(2) The diffusion rate of the more rapidly diffusing media Fe and Si markedly decreases, while that of the more slowly diffusing media Ni and Mg increases, in the case of simultaneous diffusion of Fe plus Ni, and Si plus Mg. There is however scarcely any difference between the simultaneous and the separate diffusion in the case of aading Cu and Zn which have the same rate of diffusion when added alone.
