Method for chemically stripping a cobalt-base substrate
US5944909A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 2, 1998 |
| Grant date | Aug 31, 1999 |
| Priority date | — |
| Expiry date | Feb 2, 2018 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23F1/44
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A method of removing metallic compositions, such as abradable rub coatings, environmental coatings, bond coats and braze alloys, from the surface of a cobalt-base substrate, such as turbine shrouds and vanes of gas turbine engines. The method is particularly suited for the removal of nickel-base braze alloys and aluminum-containing coatings, the latter of which includes abradable MCrAlY coatings and environmentally-protective diffusion aluminide coatings. The process generally entails contacting such metallic compositions with an aqueous solution containing hydrochloric acid and nitric acid and at a solution temperature of about 130.degree. F. to about 180.degree. F. The solution completely removes nickel-base alloys and aluminum-containing compositions from a cobalt-base substrate without removal or damage to the underlying substrate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.