Patent ID: 11915861
Assignee: STAR GROUP IND. CO., LTD
Field: Materials, metallurgy (Chemistry)
Classification: CPC H  B  C | IPC B  C  H

Claim 0:
1. A method for manufacturing a rare earth sintered magnet comprising the steps of:
preparing a rare earth alloy composed of xwt % RE-ywt % B-zwt % TM-bal.wt % Fe, wherein RE is a rare earth element, TM is a 3d transition element, x=28˜35, y=0.5˜1.5, z=0˜15, and pulverizing the prepared rare earth alloy to a size of 1.0˜5.0 μm;
preparing heavy rare earth compounds and a heavy rare earth metal alloy and pulverizing the heavy rare earth compounds and the heavy rare earth metal alloy to a size of 1.0˜5.0 μm;
mixing the heavy rare earth compound powder of 40˜60 wt % with the heavy rare earth metal alloy powder of 40˜60 wt %;
mulling the pulverized rare earth alloy powder and the heavy rare earth compound powder and the heavy rare earth metal alloy powder at a ratio of 98-99 wt % pulverized rare earth alloy powder: 1-2 wt % heavy rare earth compound powder and heavy rare earth metal alloy powder, to be mixed;
aligning and compacting the mixed powder in a magnetic field, to be magnetized;
loading the magnetized mixture powder into a heating furnace and diffusing heavy rare earth elements of the heavy rare earth compounds and the heavy rare earth metal alloy to a grain boundary of the rare earth alloy under a vacuum or in an inert gas atmosphere;
sintering the powder of the rare earth alloy with the diffused heavy rare earth elements; and
performing a heat treatment to the sintered alloy,
wherein the heavy rare earth compounds are Gd-Hydride and one of the compounds which are Ho-Hydride, Dy-Hydride and Tb-Hydride as powders, and
wherein the heavy rare earth metal alloy is one of the alloys which are Gd-Al, Gd-Cu and Gd-Ag.