Functional coatings for the reduction of oxygen permeation and stress and method of forming the same
US7361386B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Jul 22, 2003 |
| Grant date | Apr 22, 2008 |
| Priority date | — |
| Expiry date | Aug 4, 2024 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/256
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
The oxidation behavior of the bond coat is improved using a HVOF nanostructured NiCrAlY coating. NiCrAlY powder is mechanically cryomilled and HVOF sprayed onto Ni-based alloy to form a nanocrystalline bond coat. Oxidation is performed on the coating to form the thermally grown oxide layer (thermally grown oxide). After heat treatment at 1000° C. for 24 and 95 hour, a homogeneous α-Al2O3 layer is formed on top of the bond coat. The nanostructured characteristic of the coating and the presence of Al2O3 within the cryomilled powders (oxidation occurred during cryomilling process) affects the nucleation of the alumina layer on the top of the coating. The formation of a continuous thermally grown oxide layer protects the coating from further oxidation and avoids the formation of mixed oxide protrusions, such as those presented in the coating sprayed using the as-received powder.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.