Kinetic analysis of spinodal decomposition process in Fe–Cr alloys by small angle neutron scattering

Abstract The rate of spinodal decomposition depends on the spatial composition distribution. In order to estimate the time dependence of its rate experimentally, the structure change was investigated in Fe–30 at.% Cr and Fe–50 at.% Cr alloys aged at 748, 773, 798, and 823 K via small angle neutron scattering and a kinetic analysis of experimental data was carried out by using the Langer–Bar-on–Miller (LBM) theory. Their theory contains a rate term of a physical meaning similar to the diffusion coefficient. As a result, it becomes clear that the rate term corresponding to the diffusion coefficient decreases as decomposition advances and this fact can be explained by the modified LBM theory considering the composition-dependent mobility.