Phase Equilibrium and Critical Phenomena in Fe-Cr-Co-V Ageing Alloys

Experimental data on phase equilibrium are obtained by methods of the high-temperature small-angle neutron scattering and X-ray diffraction from single crystals of Fe-(16-26%)Cr-14%Co-3%V (at %). For miscibility gap calculations a thermodynamic model of Fe-Cr-Co-V а-solid solutions is offered and verified. Computations of equilibrium phase compositions are compared with the experimental data and the model adequacy is confirmed. The influence of some parameters (Curie temperature, entropy of magnetic ordering, characteristics of long- and short-range of magnetic ordering) on a shape of the miscibility gap ridge is investigated for the Fe-Cr-Co-V system used for manufacturing of ductile permanent magnets.