Oxidation barrier coatings for silicon based ceramics
US7323247B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 21, 2003 |
| Grant date | Jan 29, 2008 |
| Priority date | — |
| Expiry date | Jan 28, 2025 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/30
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A protective barrier coating system including a diffusion barrier coating and an oxidation barrier coating and method for use in protecting silicon-based ceramic turbine engine components. A complete barrier coating system includes a thermal barrier coating of stabilized zirconia and an environmental barrier coating of an alloyed tantalum oxide. The oxidation barrier coating includes a layer of metallic silicates formed on a substrate of silicon nitride or silicon carbide to be protected. The oxidation barrier coating can include silicates of scandium, ytterbia or yttrium. The oxidation barrier coating may also include an inner layer of Si2ON2 between the diffusion barrier and the metallic silicate layer. The oxidation barrier coating can be applied to the substrate by spraying, slurry dipping and sintering, by a sol-gel process followed by sintering, by plasma spray, or by electron beam-physical vapor deposition. The diffusion layer of essentially pure Si3N4 can be applied to the substrate to prevent the migration of damaging cations from the protective layers to the substrate and is preferably formed by chemical vapor deposition. A method for protecting silicon based substrates c…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.