Surface nitriding method of an aluminum material, and an auxiliary agent for nitriding
US6074494A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jun 2, 1997 |
| Grant date | Jun 13, 2000 |
| Priority date | — |
| Expiry date | Jun 2, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23C8/24
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
This invention aims to provide a nitriding method of forming a relatively thick nitride layer on the surface of an aluminum material containing silicon, and an auxiliary agent for nitriding. By using a nitriding auxiliary agent mainly comprising aluminum containing a metal such as lithium or boron, which has a high bonding strength with oxygen, coexists with silicon to form substantially no silicide, or a nitriding auxiliary agent mainly comprising an Al--Mg--Cu alloy or an Mg--Zn--Cu alloy, heat treatment is applied by nitrogen gas with the aluminum material to be nitrided contacted with the nitriding auxiliary agent. Hence, a thick nitride layer can be easily formed even on the surface of an aluminum material containing silicon, and this is most suitable to surface nitride aluminum-silicon alloys, which possess superior castability.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.