Claims
- 1. A method for removing gold-nickel type braze material from brazed metallic articles selected from the group consisting of stainless steels, cobalt superalloys and nickel superalloys, without significant base metal attack consisting of:
- immersing the brazed articles in a heated aqueous solution which contains from about 40 to about 50% concentrated nitric acid, about 0.01 to about 0.1 mole/l sulfate ions, from about 0.005 to about 0.2 mole/l chloride ions, and at least about 0.001 mole/l metal ions, said solution being held at a temperature between about 75.degree. and 150.degree. F., for a period of time sufficient to remove the braze without adversely affecting the metallic article.
- 2. A process as in claim 1 wherein the solution is ultrasonically agitated to increase the rate of braze material removal.
- 3. A method as in claim 1 wherein the metal ions are selected from the group consisting of copper, iron, nickel, chrome, cobalt, cerium and sodium and mixtures thereof.
- 4. A method as in claim 1 wherein the sulfate ion concentration is derived from sulfuric acid and the chloride ion concentration is derived from a metal chloride.
- 5. A method as in claim 1 wherein the sulfate ion concentration is derived from a metal sulfate and the chloride ion concentration is derived from HCl.
- 6. A method as in claim 1 wherein the solution contains nitric acid, copper sulfate and ferric chloride.
Parent Case Info
This is a continuation of application Ser. No. 933,944 filed on Aug. 15, 1978, now abandoned.
Government Interests
The invention herein described was made in the course of or under a contract or subcontract with the Department of the Air Force.
US Referenced Citations (11)
Foreign Referenced Citations (1)
Number |
Date |
Country |
2103261 |
Oct 1972 |
DEX |
Non-Patent Literature Citations (1)
Entry |
Flitsch, "Etch for Removing Gold" IBM Technical Disclosure Bulletin vol. 10, No. 4, (9/67) p. 355. |
Continuations (1)
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Number |
Date |
Country |
Parent |
933944 |
Aug 1978 |
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