Process for coating a passivatable metal or alloy substrate with an oxide layer, and fuel assembly cladding and guide tubes and spacer grid coated with an oxide layer
US6033493A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Oct 28, 1997 |
| Grant date | Mar 7, 2000 |
| Priority date | — |
| Expiry date | Oct 28, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23C16/452
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
Surface preoxidation of the substrate is carried out by bringing the substrate into contact with an oxidizing gas excited by a cold plasma, the substrate being situated in the flowing afterglow of the cold plasma used to excite the oxidizing element and being heated to an oxidation temperature of less than 500.degree. C. A metal oxide is formed at the surface of the preoxidized substrate by heterogeneous oxidation of a metal halide with a gas mixture including an oxidizing element activated by a cold plasma. The oxidizing gas mixture is brought into contact with the halide as directly as possible in the vicinity of the substrate arranged in the far flowing afterglow of the cold plasma. The cold plasma is preferably generated by microwaves. The process can be used in particular for producing a protective coating on a cladding tube of a nuclear fuel rod.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.