US4172548A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of fluxless brazing for aluminum structures
Assignee: Sumitomo Precision Products Co Ltd
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Filing: 1977-12-29
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Granted: 1979-10-30
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Expires: 1997-12-29
Abstract
Abstract Failure under stress of brazed aluminum assemblies prepared by fluxless brazing is prevented by controlling the grain size before brazing of the material in contact with the brazing alloy to be at least 60μ.
Inventors
- 👤 Masakazu Nakamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 19:51
CPC Classifications
F; F28; F28F; F28F21/00; F28F21/08; F28F21/081; F28F21/084; B; B23; B23K; B23K1/00; B23K1/20; C; C22; C22F; C22F1/00; C22F1/04; F28F3/00; F28F3/02; F28F3/025; B23K2101/00; B23K2101/04; B23K2101/14; B23K2103/00; B23K2103/08; B23K2103/10
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
65 words
In a method of joining aluminum alloy members of a structure by fluxless brazing by applying fluxless brazing alloy between said aluminum members to be joined and heating said members to effect brazing thereof, the improvement comprising: employing as said aluminum alloy members, aluminum alloy material which has been treated such that the crystal grain size of the alloy material is at least 60 μm.
Claim 2
Dependent Claim
65 words
In a method of joining aluminum alloy members of a structure by fluxless brazing by applying fluxless brazing alloy between said aluminum members to be joined and heating said members to effect brazing thereof, the improvement comprising: employing as said aluminum alloy members, aluminum alloy material which has been treated such that the crystal grain size of the alloy material is at least 60 μm.
Claim 3
Dependent Claim
40 words
The method according to claim 1, wherein said aluminum alloy structure comprising at least one relatively thin member joined to a relatively thick member, and a grain size of the alloy of the thinner member is at least 60 μm.
Claim 4
Dependent Claim
32 words
The method according to claim 2 wherein said aluminum alloy structure is the core of a heat exchanger and the thin member of the structure is the fin of said heat exchanger.
References Cited (Backward Citations)
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Cited
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US4077810A
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US4053969A
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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) | 1982-10-29 | 1983-04-30 | 1983-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-10-29 | 1987-04-30 | 1987-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-10-29 | 1991-04-30 | 1991-10-30 | $7700.00 | Window Closed / Lapsed |