Hydrogenation of Nd-Fe Alloys under Conditions of Different Pressure and Hydrogen Concentration

Abstract

The paper presents the research results of the process of hydride grinding of Nd-Fe alloys, which are used for solid-phase alloying of base magnetic alloys having Nd-Fe-B system in order to improve magnetic characteristics of rare-earth permanent magnets. Alloys having rare-earth metals including Nd-Fe can be produced with the help of the out-of-furnace fluoride technology designed by the authors of this article. Hydrogenation of Nd-Fe alloys is used at the stage of their grinding. It is determined by complexity of mechanical grinding of these alloys because of their tensility and high strength. The thermodynamics of the process of alloy hydrogenation is considered. The effects of hydrogen surplus, the process scale and the surface area of alloys on their hydrogenation rate are investigated. The paper also presents the results of metallographic and roentgen-phase analyses of the sample surfaces of alloys which were hydrogenated. The analysis of the specific surface area of the materials is given.

Study of production process of refined rare-earth alloys and addition alloys

“…The modifier was a surface-active material and it ensured the initiation of active crystallization grains in the whole bulk of the solidifying material. It allowed producing the identical microstructure in the bulk of the ingot and facilitating the subsequent process of hydrogen comminuting when the material hydrogenation took place along the boundaries of grain space [7]. mix material was put onto a small platform with the modifier; the platform was placed at the inducer edge; the inducer was heated and the material under study was melted; then the modifier was added into the molten material; it took 0.5-1.0 min to mix the modifier and the melt; then the melt was discharged into the copper casting mold.…”