Diffusion of Copper in Nickel and Aluminum

Diffusion of copper in nickel and aluminum has been studied by the residual activity technique in the temperature ranges of 850° to 1050°C, and 350° to 630°C, respectively. Diffusivities (cm²/sec) are expressed as $$\begin{array}{c}{D}_{\mathrm{Cu}}/{\mathrm{Ni}}_{\mathrm{Cu/Ni}}\text{=0.724\hspace{0.17em}}\exp \text{[−(61\hspace{0.17em}000/RT)]}\\ D_{\mathrm{Cu}}/{\mathrm{Al}}_{\mathrm{Cu/Al}}\text{=0.150\hspace{0.17em}}\exp \text{[−(30\hspace{0.17em}200/RT)].}\end{array}$$ Results have been compared with those calculated from the theories of diffusion based on charge and size difference between the impurity and the solvent atoms.