Diffusion processes in the FeNi system

In this paper we present the experimental results of a study on the self-diffusion coefficients of both components in the f.c.c. phase of the FeNi binary system; these results were obtained using the radioisotopes 59Fe and 63Ni together with the measurements of the interdiffusion coefficient in this system obtained with the aid of an electron micro-analyser. Diffusion measurements were supplemented by thermodynamic mixing data for the same phase measured by the vapour pressure technique; the two sets of data enabled us to verify Darken's theory of interdiffusion. Experimental results of 185W impurity diffusion in the f.c.c. phase of the FeNi system are also presented.