Trostianchyn A. Influence of hydrogen treatment on structure and properties of commercial magnetic alloys based on Sm-Co and Dd-Fe-B systems

Phase-structure transformations in hydrogenated alloys based on rare-earth metals (REM). To determine the regularities of hydrogen influence (HDDR process) on phase-structure state of Sm-Co and Dd-Fe-B systems alloys and to give the recommendations about the optimization theirs hydrogen treatment for the improvement of structure and magnetic properties. Methodological base of the study is a volumetric analysis, differential thermal analysis, X-ray and microroentgenspectral analyses, metallographic analysis, granulometric analysis and measuring magnetic properties. It was found that in the case of two-phase commercial alloys the disproportionation starts from the impurity phases and this leads to the formation of fine-grained structure with grain size 0.2-0.5 ?m. Hydrogen treatment by means of the HDDR increases energy product and pull force of Dd-Fe-B system alloys by 8-10% and 23-27 % respectively. The results of the investigations are used at the production of permanent magnets in "Expromag" Ltd. (Dniprodzerzhinsk).