Spinodal Decomposition in Fe - 32Cr

Spinodal decomposition in iron-chromium alloys has been studied for various compositions and aging temperatures by several workers using small angle neutron scattering. The data of the present study and that of previous workers are reviewed in order to better define the coexistence curve of this system as well as to provide an experimental basis for comparison with current nonlinear theories of spinodal decomposition. Regarding the coexistence curve, it is argued that the qualitative changes in the scattering pattern with composition and aging temperature are consistent with the experimentally determined boundary, rather than those calculated for this system. Quantitative analysis of the kinetic development of scattering from Fe-32Cr samples allows direct comparison with predictions of nonlinear theories of spinodal decomposition. The time dependence of the position of the peak maximum has been given by several theories as t − . The value of o found for Fe-32Cr increased with increasing aging temperature, extrapolating near the value of 1/6 at the estimated spinodal temperature.