A numerical analysis was carried out to examine the effect of solidification on the concentration distribution of a solute in an Ag/Ag-5at%Au diffusion couple in liquid diffusion measurements using the long-capillary method. Shrinkage-induced fluid flow in the solidifying sample was calculated, and the solute movement due to fluid flow was evaluated. In the analysis, molten samples in graphite crucibles were cooled in air using 3 different cooling rates. Flat iso-concentration contours in the horizontal plane of the diffusion couple were found in samples with a low cooling rate. Concave iso-concentration contours were formed in samples with high cooling rates. These features of the simulation agreed with experimental results.

Numerical Analysis of Solidification Effect on Diffusion Measurement in Liquid using the Long Capillary Method. K.Ohsasa, A.Hirata, M.Uchida, T.Itami: Materials Transactions, 2003, 44[6], 1068-74