US4443274A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for forming a protective film on Cu-Sn alloys
Assignee: Olin Corp
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Filing: 1982-12-03
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Granted: 1984-04-17
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Expires: 2002-12-03
Abstract
Abstract A heat treatment for providing copper-tin alloys with a substantially continuous tin-phosphorous-oxide protective layer that improves the appearance and the tarnish resistance of the alloys is disclosed. The heat treatment comprises heating the alloys in a reducing atmosphere having a dew point of at least about 65° F. and a temperature in the range of about 700° C. to about 900° C. for a time in the range of about 2 hours to about 24 hours.
Inventors
- 👤 Andrew J. Brock
- 👤 Frank N. Mandigo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 03:21
CPC Classifications
C; C23; C23C; C23C8/00; C23C8/06; C23C8/08; C23C8/10
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
112 words
Process for forming a protective layer on a surface of a copper-tin alloy containing phosphorous comprising: providing an alloy comprising about 2.5% to about 15% tin, about 0.05% to about 1.5% phosphorous and the balance consisting essentially of copper, forming tin oxide on the surface of said alloy and reducing said tin oxide by heating said alloy at a temperature in the range of about 700° C. to about 900° C. in a reducing atmosphere having a dew point of at least about 65° F. for a time sufficient to transform said tin oxide initially into globules of tin containing phosphorous and then into a substantially continuous protective layer of tin-phosphorous oxide.
Claim 2
Dependent Claim
112 words
Process for forming a protective layer on a surface of a copper-tin alloy containing phosphorous comprising: providing an alloy comprising about 2.5% to about 15% tin, about 0.05% to about 1.5% phosphorous and the balance consisting essentially of copper, forming tin oxide on the surface of said alloy and reducing said tin oxide by heating said alloy at a temperature in the range of about 700° C. to about 900° C. in a reducing atmosphere having a dew point of at least about 65° F. for a time sufficient to transform said tin oxide initially into globules of tin containing phosphorous and then into a substantially continuous protective layer of tin-phosphorous oxide.
Claim 3
Dependent Claim
100 words
Process for forming a protective layer on a surface of a copper-tin alloy comprising: providing a copper tin alloy, forming tin oxide on the surface of said alloy and reducing said tin oxide by heating said alloy at a temperature range of about 700° C. to about 900° C. in a reducing atmosphere having a dew point of at least about 65° F. and having a source of phosphorous within said reducing atmosphere for a time sufficient to transform said tin oxide initially into globules of tin containing phosphorous and then into a substantially continuous protective layer of tin-phosphorous oxide.
Claim 4
Dependent Claim
100 words
Process for forming a protective layer on a surface of a copper-tin alloy comprising: providing a copper tin alloy, forming tin oxide on the surface of said alloy and reducing said tin oxide by heating said alloy at a temperature range of about 700° C. to about 900° C. in a reducing atmosphere having a dew point of at least about 65° F. and having a source of phosphorous within said reducing atmosphere for a time sufficient to transform said tin oxide initially into globules of tin containing phosphorous and then into a substantially continuous protective layer of tin-phosphorous oxide.
Claim 5
Dependent Claim
45 words
The process of claim 1 wherein said reducing and layer forming step further comprises: heating said alloy at a temperature in the range of about 750° C. to about 850° C. for a time in the range of about 2 hours to about 24 hours.
Claim 6
Dependent Claim
37 words
The process of claim 1 wherein said step of providing a copper-tin alloy comprises: providing an alloy containing about 4% to about 8% tin, about 0.2% to about 0.5% phosphorous and the balance consisting essentially of copper.
Claim 7
Dependent Claim
22 words
The process of claim 1 further comprising: said dew point being in the range of about 90° F. to about 120° F.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-04-17 | 1987-10-17 | 1988-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-04-17 | 1991-10-17 | 1992-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-04-17 | 1995-10-17 | 1996-04-17 | $7700.00 | Window Closed / Lapsed |