Особенности формирования высококоэрцитивной структуры сплавов (Sm,Zr)(Со,Cu,Fe)z при варьировании соотношения (4f-,4d-)/(3d-) элементов

Abstract

Processes of the formation of high-coercivity state of Sm0.85Zr0.15(Co0.702Cu0.088Fe0.210)z alloys with different z = 6.0, 6.5 and 6.8, which is the value characterized the relationship of (4f-,4d-)/(3d-) elements in these alloys, are studied. It is shown the interrelation of the chemical composition of samples and their microstructure with the coercive force formed in the course of isothermal tempering and tempering during slow cooling (or stepped tempering). The interrelation of the high-coercivity state of the alloys and quantitative ratio (volume fractions) of the main structural components based on the 2:17R and 1:5H phases is discussed. It is shown that the cellular morphology of the alloy, which corresponds to the high-coercivity state, forms during isothermal tempering, whereas the final phase compositions of the main structural components form in the temperature range from the isothermal aging temperature to 400 °С during stepped (slow) cooling or upon quenching. The magnetic properties of sample in the high-coercivity state are determined by the degree of completeness of phase transformations of the main structural components; this directly depends on their quantitative relationships and the relationship of the (4f-,4d-)/(3d-) elements, i.e., on the z value in the alloy formula (Sm,Zr)(Со,Cu,Fe)z.