Method of producing Nd-Fe-B based nanophase power
US6676730B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 23, 2001 |
| Grant date | Jan 13, 2004 |
| Priority date | — |
| Expiry date | May 23, 2021 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB22F2998/10
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The present invention relates to a method of producing Nd—Fe—B based nanophase powder, or more particularly, to a method of producing Nd2Fe14B phase powder of 1 &mgr;m or less, having Nd2Fe14B crystal grains of 50 nm or less, which comprises the following steps of: producing a precursor powder having a mixture of elements of Nd, Fe and B by means of spray-drying a mixed aqueous solution comprising Nd metal salt, Fe metal salt, and boric acid; producing an oxide composite powder by means of desaltation of said powder; reducing the composite oxide powder, and ball-milling of said composite powder comprising Nd oxides and &agr;-Fe; producing a mixed powder of Nd2Fe14B/CaO phase by mixing Ca to said composite powder after milling; and removing CaO by washing said composite powder with water, followed by drying.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.