US4478651A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Protective film on Cu-Sn alloys
Assignee: Olin Corp
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Filing: 1983-10-03
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Granted: 1984-10-23
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Expires: 2003-10-03
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
2026-11-02 01:54
CPC Classifications
C; C23; C23C; C23C8/00; C23C8/06; C23C8/08; C23C8/10; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12535; Y10T428/12583; Y10T428/1259; Y10T428/12611; Y10T428/12618
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
26 words
A copper-tin alloy having improved tarnish resistance, said alloy comprising: a substantially continuous, thermally produced layer of tin-phosphorous-oxide on at least one surface of said alloy.
Claim 2
Dependent Claim
26 words
A copper-tin alloy having improved tarnish resistance, said alloy comprising: a substantially continuous, thermally produced layer of tin-phosphorous-oxide on at least one surface of said alloy.
Claim 3
Dependent Claim
55 words
The copper-tin alloy of claim 1 further comprising said tin-phosphorous-oxide layer being formed by: heating said alloy so that tin oxide forms on said alloy surface; reducing said tin oxide by reacting said tin oxide with phosphorous so that globules of tin containing phosphorous are formed; and continuing heating until said globules form said layer.
Claim 4
Dependent Claim
32 words
The copper-tin alloy of claim 1 further comprising: said alloy comprising from about 2.5% to about 15% tin, from about 0.05% to about 1.5% phosphorous and the balance consisting essentially of copper.
Claim 5
Dependent Claim
32 words
The copper-tin alloy of claim 1 further comprising: said alloy comprising from about 4% to about 8% tin, from about 0.2% to about 0.5% phosphorous and the balance consisting essentially of copper.
Claim 6
Dependent Claim
24 words
The copper-tin alloy of claim 1 wherein said tin-phosphorous oxide layer comprises a mixed oxide close to 3SnO 2 :2P 2 O 5 .
Claim 7
Dependent Claim
59 words
The copper-tin alloy of claim 1 further comprising said tin-phosphorous-oxide layer being formed by heating said alloy at 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 in a reducing atmosphere having a dew point of at least about 65° F.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-10-23 | 1988-04-23 | 1988-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-23 | 1992-04-23 | 1992-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-23 | 1996-04-23 | 1996-10-23 | $7700.00 | Window Closed / Lapsed |