Method for improving corrosion resistance of neodymium-iron-boron materials by low-temperature oxidation and/or nitridation treatment
US12112884B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 1, 2022 |
| Grant date | Oct 8, 2024 |
| Priority date | — |
| Expiry date | Aug 21, 2042 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E10/72
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method for improving the corrosion resistance of NdFeB materials is provided. The method includes in-situ growing a layer of oxide, nitride, or oxynitride on the surface of NdFeB magnet correspondingly by performing at least one of an oxidation treatment and a nitridation treatment at low temperature in a range of 200˜400° C., thereby significantly improving the corrosion resistance of the magnet. The method is simple to operate, low-cost, green, safe, and efficient. Depending on the parameters of the low-temperature oxidation and/or nitridation treatment, the thickness of the oxide, nitride, or oxynitride layer is adjustable from 10 nm to 100 μm, which can improve the corrosion resistance of the magnet while maintaining excellent magnetic properties. Moreover, the thin surface layer is in-situ grown on the NdFeB substrate, which is strong and stable over a long service period and can be applied for mass production.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.