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

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.