Coating system to permit direct brazing of ceramics
US6528123B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 28, 2000 |
| Grant date | Mar 4, 2003 |
| Priority date | — |
| Expiry date | Jun 28, 2020 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B2237/72
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
This invention relates to a method for preparing the surface of a ceramic component that enables direct brazing using a non-active braze alloy. The present invention also relates to a method for directly brazing a ceramic component to a ceramic or metal member using this method of surface preparation, and to articles produced by using this brazing method. The ceramic can be high purity alumina. The method comprises applying a first coating of a silicon-bearing oxide material (e.g. silicon dioxide or mullite (3Al2O3.2SiO2) to the ceramic. Next, a thin coating of active metal (e.g. Ti or V) is applied. Finally, a thicker coating of a non-active metal (e.g. Au or Cu) is applied. The coatings can be applied by physical vapor deposition (PVD). Alternatively, the active and non-active metals can be co-deposited (e.g. by sputtering a target made of mullite). After all of the coatings have been applied, the ceramic can be fired at a high temperature in a non-oxidizing environment to promote diffusion, and to enhance bonding of the coatings to the substrate. After firing, the metallized ceramic component can be brazed to other components using a conventional non-active braze alloy. Alternat…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.