On Determination of Inter and Intrinsic Diffusion Coefficients in Binary System

Abstract

The conceptions of various frames of reference for binary interdiffusion, which have been partly reported in the past, are summarized. The rational method of determining the inter- and intrinsic diffusion coefficients in the general case, where total volume of a diffusion couple changes during diffusion, is reviewed and discussed. The interdiffusion coefficients ordinarily defined are correctly calculated irrespective of reference frame. The magnitude of the intrinsic diffusion coefficients depends on what is chosen for the frame of reference. The useful intrinsic diffusion coefficient in alloys is the one relative to the number of mole fixed frame of reference.