Rare earth cast alloy permanent magnets and methods of preparation
US5538565A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 24, 1993 |
| Grant date | Jul 23, 1996 |
| Priority date | — |
| Expiry date | Jun 24, 2013 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D6/00
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A rare earth iron permanent magnet including at least one rare earth element, iron and boron as primary ingredients. The magnet can have an average grain diameter of less than or equal to about 150 .mu.m and a carbon content of less than or equal to about 400 ppm and an oxygen content of less than or equal to about 1000 ppm. The permanent magnet is prepared by casting a molten alloy. In one embodiment, the cast body is heat treated at a temperature of greater than or equal to about 250.degree. C. Alternatively, the material can be cast and hot worked at a temperature of greater than or equal to about 500.degree. C. Finally, the material can be cast, hot worked at a temperature of greater than or equal to about 500.degree. C. and then heat treated at a temperature of greater than or equal to about 250.degree. C. The magnets provided in accordance with the invention are relatively inexpensive to produce an have excellent performance characteristics.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.