Phosphate coated iron powder and method for the manufacturing thereof
US6348265B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 21, 1998 |
| Grant date | Feb 19, 2002 |
| Priority date | — |
| Expiry date | Aug 21, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2991
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The invention concerns a novel low oxygen powder comprising particles of a base powder consisting of essentially pure iron having an insulating oxygen- and phosphorus-containing barrier. The oxygen content of the new powder is at most 0.2% by weight higher than the oxygen content of the base powder, and the ratio O:P is between 30 and 1, preferably between 15 and 2 and most preferably between 10 and 3 as measured by the ESCA method. The invention also concerns a new method of preparing an iron-based powder comprising the steps of preparing a base powder consisting of a water atomized iron powder or a sponge iron powder, subjecting the mixture to treatment with a solution of phosphoric acid in an organic solvent and drying the obtained mixture, whereby the solution of phosphoric acid is sprayed on the base powder while being mixed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.