Alloy decomposition in Cu-Ni-Fe. I. Equilibrium states and kinetics of homophase fluctuations

Abstract
Thermodynamic equilibrium states, the kinetics of short-range clustering, and decomposition of quasibinary Cu62Ni(Fe) alloys are studied by means of diffuse and small-angle neutron scattering. From an Ornstein-Zernicke analysis of the results, the temperature- and concentration-dependent thermodynamic parameters and the coherent miscibility gap temperatures are obtained. From an analysis of the kinetics in the homophase and heterophase regions of the phase diagram according to the model of Cook, Hilliard and de Fontaine (1969), chemical diffusion coefficients are determined. The parameters of the CuNiFe alloys are compared with literature data on the CuNi alloy system.