The effects of diffusion-induced recrystallization on volume diffusion in the Cu-Ni system were investigated. The Cu-Ni diffusion couples were annealed at 500, 550, 600 or 650C for 120 or 200h and were used to calculate volume diffusion in the binary system. Using characterization techniques such as focussed ion beam and transmission electron microscopy, observations of the interdiffusion zone revealed areas which contained diffusion-induced recrystallization and non diffusion-induced recrystallization. The volume diffusion of Ni into Cu across the non diffusion-induced recrystallization regions was calculated by using the Boltzmann-Matano method at 1wt%Ni (table 1). The calculated volume diffusivities across the diffusion-induced recrystallization zones were approximately 3 to 4 orders of magnitude higher than the volume diffusion based upon non diffusion-induced recrystallization information. The published values of volume diffusion in the Cu-Ni system were also higher than the non diffusion-induced

recrystallization values by about an order of magnitude; thus implying that previous values included grain-boundary contributions.

Effects of Diffusion Induced Recrystallization on Volume Diffusion in the Copper-Nickel System. S.M.Schwarz, B.W.Kempshall, L.A.Giannuzzi: Acta Materialia, 2003, 51[10], 2765-76

Table 1

Diffusivity of Ni in Cu