Diffusion-induced recrystallization was studied experimentally by using diffusion couples which consisted of a pure Cu single crystal and a binary Ni-Cu polycrystalline alloy. During annealing (873K, 1 to 72h), a fine-grained (diffusion-induced recrystallization) region formed at the interface of each diffusion couple and grew mainly towards the Cu phase. The thickness of the diffusion-induced recrystallization region increased, with increasing annealing time, according to a power-law relationship with a proportionality coefficient of 2.18 x 10-8m and an exponent of 0.55. These values were independent of the composition of the Ni phase; to within experimental uncertainty. The compositional differences across the moving boundaries of the diffusion-induced recrystallization region, on both the Cu and Ni sides, decreased in approximate inverse proportion to the fourth root of the annealing time. For each annealing time, the compositional difference on the Ni phase side decreased monotonically with increasing Cu concentration in the Ni phase. There was no clear relationship between the compositional difference on the Cu side, and the Cu concentration.

Observations of Diffusion-Induced Recrystallization in Binary Ni/Cu Diffusion Couples Annealed at an Intermediate Temperature. Y.Yamamoto, S.Uemura, M.Kajihara: Materials Science and Engineering A, 2001, 312[1-2], 176–81