METHOD OF PRODUCING A POWDER OF AN ALLOY BASED ON A RARE-EARTH METAL FROM SECONDARY MAGNETIC MATERIALS BASED ON A RARE-EARTH METAL-IRON-BORON SYSTEM Russian patent published in 2024 - IPC C22C1/05 H01F1/53 

FIELD: powder metallurgy.

SUBSTANCE: invention relates to production of sintered permanent magnets based on alloys of rare-earth metal (REM)-Fe-B system from secondary materials, including those extracted from used electronic devices. Method of obtaining powder of alloy hydride based on rare-earth metal from secondary magnetic materials based on rare-earth metal-iron-boron system involves demagnetization of secondary magnetic materials by heating and obtaining a powder therefrom by hydrogen dispersion. Secondary magnetic alloys of rare-earth metal-iron-boron system are used as secondary magnetic materials, demagnetization of secondary magnetic alloys of the rare-earth metal-iron-boron system is carried out in an autoclave placed in a shaft furnace at a temperature of not more than 400 °C for 1–4 hours in an average vacuum, and then performing the three-stage cleaning of the surface of the secondary magnetic alloys of the rare-earth metal-iron-boron system by first sandblasting them with slag beads at pressure of 300 kPa, etching in etching baths in 1–3 % aqueous solution of hydrochloric acid for up to 5 minutes and subsequent heat treatment of secondary magnetic alloys of rare-earth metal-iron-boron system in autoclave placed in shaft furnace at medium vacuum and temperature of 300 °C for 1 hour. Further, the autoclave with purified secondary magnetic alloys of the rare-earth metal-iron-boron system is filled with argon to an excess pressure of 100 kPa and performing its cooling with transfer from the shaft furnace into a container with water, and upon reaching room temperature in the autoclave, hydride powder is obtained by hydrogen dispersion using hydrogen, obtained by desorption from hydride of LaNi₅ alloy and pumped into autoclave until reaching stable and not reduced pressure from 30 to 70 kPa.

EFFECT: obtaining hydride powders with hydrogen content of not less than 0_45 wt %, with reduced oxygen content, with grain size from 1 to 15 mcm, which can be used for charging to powders of base alloy rare-earth metal (REM)-Fe-B with obtaining magnets with restored magnetic characteristics.

1 cl, 2 dwg, 1 tbl, 1 ex