The influence of the Kirkendall effect in multiphase diffusion couples of the Ti-Ni and Co-Si systems was considered in terms of the velocity of the Kirkendall frame of reference relative to the laboratory-fixed frame of reference. It was found that, in the case of a Co/CoSi2 couple annealed at 1100C, 2 so-called Kirkendall planes appeared in different product layers. The same phenomenon was observed in a Ti/Ni diffusion couple which was annealed at 850C. In the case of a Co/Co52Si48 reaction couple, no Kirkendall plane was found in any of the product layers. Thoria particles, which were introduced between the initial end-members before heat-treatment, were later found at the ε-Co/Co2Si interface. These effects could be predicted.

The Kirkendall Effect in Multiphase Systems. M.J.H.van Dal, A.A.Kodentsov, F.J.J.van Loo: Solid State Phenomena, 2000, 72, 111-5