Concepts of ordering, phase separation, and phase transformations in metallic solid solutions are discussed in the context of the latest experimental data on the microstructure of Fe-M alloys. It is shown that the type of chemical interaction between alloy component atoms depends on the degree of the localization of 3d-valence electrons on atoms rather than on the ratio of energies of ordering in different coordination shells. The morphology of the products of phase transformations in alloys with a tendency to ordering or phase separation is considered, and the known mechanisms of phase decomposition are analyzed. The decomposition of alloys having a tendency to ordering and to phase separation is described in thermodynamic terms. It is shown that solid-solution fields in phase diagrams are in fact regions where the alloys have a tendency to phase separation and where, at certain correlations between free-energy components, separation microstructures are formed. It is noted that phase transformations in alloys can occur at different levels of the structure of matter: the ’primary’ occur at the level of changes (ordering-phase separation) in the electronic structure, and the ’secondary’ are realized at the level of changes (order-disorder) in the microstructure.

PACS: 64.60.Cn, 64.75.+g, 82.60.Lf (all) DOI: 10.1070/PU2006v049n06ABEH003175 URL: https://ufn.ru/en/articles/2006/6/c/ 000241498900003 2-s2.0-33750406729 2006PhyU...49..593U Citation: Ustinovshchikov Yu I, Pushkarev B E "Ordering, phase separation, and phase transformations in Fe-M alloys" Phys. Usp. 49 593–603 (2006) BibTexBibNote ® (generic)BibNote ® (RIS)MedlineRefWorks Оригинал: Устиновщиков Ю И, Пушкарев Б Е «Упорядочение, расслоение и фазовые превращения в сплавах Fe-M» УФН 176 611–621 (2006); DOI: 10.3367/UFNr.0176.200606c.0611