Process for producing the rare earth alloy powders
US4770702A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 20, 1988 |
| Grant date | Sep 13, 1988 |
| Priority date | — |
| Expiry date | Jan 20, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F1/0573
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A rare earth-iron-boron alloy powder which consists essentially of: PA1 12.5 to 20 at % R wherein R.sub.1 is 0.05 to 5 at %, 4 to 20 at % B, and 60 to 83.5 at % Fe, wherein R.sub.1 is at least one heavy rare earth element selected from the group consisting of Gd, Tb, Dy, Ho, Er, Tm and Yb, 80 to 100 at % of R.sub.2 consists of Nd and/or Pr, the balance in the R.sub.2 being at least one element selected from the group consisting of rare earth elements including Y and except for R.sub.1, and R=R.sub.1 =R.sub.2 by atomic %, wherein a major phase of at least 80 vol % of the entire alloy coinsists of a tetragonal structure, and wherein oxygen does not exceed 10,000 ppm, carbon does not exceed 1000 ppm and calcium does not exceed 2000 ppm. The alloy powder is produced by directly reducing a mixture comprising rare earth oxide, iron and other ingredients or oxide thereof with a reducing agent Ca and CaCl.sub.2, putting the reduced product into water, then treating with water. Up to 35 at % Co may be substituted for Fe.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.