Interdiffusion in the binary diffusion couples under a strong gravitational field

Interdiffusion in the Cu vertical bar Cu30Zn diffusion couples under a strong gravitational field was investigated at 400 degrees C. The Cu-Brass diffusion couples were prepared by electrolytic plating method. Two samples were centrifuged at 0.4x10(6) G for 60 hours. The initial contact interface was perpendicular to the gravitational force direction. The two different orientations of the samples were studied: with Cu 1) downside and 2) upside of the gravitational force direction. It was found that interdiffusion was markedly affected by the gravity field. This was caused by the sedimentation of atoms where heavy Cu atoms move in the direction of the strong gravitational field. A numerical simulation of the sedimentation process is self-consistent with experimental results.