EP0034041A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method for cleaning metal parts
Assignee: University of Dayton
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Filing: 1981-02-04
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Granted: —
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Expires: 2001-02-04
Abstract
Abstract A method for relatively low temperature cleaning of metal parts, particularly stainless steels, superalloys, solid solution superalloys and gamma prime hardened nickel alloy parts, in order to render them brazable or otherwise bondable is provided which utilises a C-O-H-F atmosphere as the primary cleaning material. The preferred source of the C-O-H-F atmosphere is by thermal decomposition of a fluorocarbon resin to which is added a low moisture-containing hydrogen gas. The atomic ratio of H to O in this atmosphere is 10<4> or greater.
Inventors
- 👤 Jack W. Chasteen
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 03:46
CPC Classifications
B; B23; B23K; B23K1/00; B23K1/20; B23K1/206; C; C23; C23G; C23G5/00
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
117 words
A method for cleaning an unbrazable metal part to render it brazable or otherwise bondable characterised in that it comprises the following steps in the order specified: (a) subjecting said part in a hermetically sealed chamber, to the action of a gaseous atmosphere, said atmosphere containing the elements C-0-H-F and having an H/O atomic ratio of 10 4 or greater, (b) at the same time heating said chamber to a temperature below 1000°C, (c) allowing said part to remain in said heated chamber filled with said atmosphere for a period of time sufficient to clean said part and render it brazable, and (d) cooling said chamber and said part prior to removing it from said sealed chamber.
Claim 2
Independent Claim
117 words
A method for cleaning an unbrazable metal part to render it brazable or otherwise bondable characterised in that it comprises the following steps in the order specified: (a) subjecting said part in a hermetically sealed chamber, to the action of a gaseous atmosphere, said atmosphere containing the elements C-0-H-F and having an H/O atomic ratio of 10 4 or greater, (b) at the same time heating said chamber to a temperature below 1000°C, (c) allowing said part to remain in said heated chamber filled with said atmosphere for a period of time sufficient to clean said part and render it brazable, and (d) cooling said chamber and said part prior to removing it from said sealed chamber.
Claim 3
Dependent Claim
28 words
A method as claimed in claim 1 further characterised in that said H/0 atomic ratio is substantially 10 4 and said temperature is approximately 800-below 1000°C, preferably 800-850°C.
Claim 4
Dependent Claim
31 words
A method as claimed in claim 1 further characterised in that said H/0 atomic ratio is substantially 105 and said temperature is approximately 700-below 1000 0 , preferably 700-750 0 C.
Claim 5
Independent Claim
54 words
A method as claimed in any of claims 1, 2 or 3 further characterised in that said C-O-H-F atmosphere is produced by the thermal decomposition of a fluorocarbon resin preferably polytetrafluoroethylene to which there is added a low moisture-containing hydrogen gas without the introd- duction of any substantial amounts of any other non-inert gases.
Claim 6
Dependent Claim
24 words
A method as claimed in claim 4 further characterised in that the moisture present in said hydrogen gas is less than substantially 200 ppm.
Claim 7
Independent Claim
36 words
A method as claimed in any of claims 1 to 5, further characterised in that said unbrazable metal part is unbrazable stainless steel, a superalloy, a solid solution superalloy, or a gamma prime hardened nickel alloy.
References Cited (Backward Citations)
US4162185A
Cited
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