US4556165A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of brazing aluminum employing fluoaluminate flux
Assignee: Rio Tinto Alcan International Ltd
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Filing: 1984-06-20
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Granted: 1985-12-03
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Expires: 2004-06-20
Abstract
Abstract In the brazing of aluminum a flux composed of a mixture of alkali metal fluoaluminates, with or without admixed AlF 3 , is employed. The flux has a composition of AlF 3 about 53-62%, KF about 35-44%, and LiF about 2-7%, in terms of simple compounds. The flux has a liquidus temperature in the range of 490°-560° C. depending on its actual composition. The flux is of particular utility when brazing aluminum containing 0.4-2% magnesium and/or having a low solidus temperature and is preferably employed in an atmosphere of a dry, inert gas.
Inventors
- 👤 Satoshi Yamawaki
- 👤 Atsushi Sugihara
- 👤 Yasushi Kobayashi
- 👤 Hiroshi Ishida
- 👤 Yukio Kuramasu
- 👤 Ichisei Gotoh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:39
CPC Classifications
B; B23; B23K; B23K35/00; B23K35/22; B23K35/36; B23K35/3601; B23K35/3603; B23K35/3605
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
147 words
A method of producing a brazed joint between an aluminum or aluminum alloy component and another metallic component which comprises interposing between said components a body of a brazing alloy having a lower liquidus temperature than the solidus temperature of said components and a body of a flux consisting essentially of a mixture of fluoaluminate complexes containing Al, F, K, and Li atoms in said mixture, or a mixture of such complexes with aluminum fluoride, said flux having the Al, F, K, and Li atoms thereof present in amounts corresponding to the following proportions of the simple compounds: aluminum fluoride about 53-62% potassium fluoride about 35-44% lithium fluoride about 2-7% said flux containing up to about 2% entrained impurities, all percentages being by weight; and heating said assemblage to a temperature above the liquidus temperature of said brazing alloy and below the solidus temperature(s) of said components.
Claim 2
Independent Claim
147 words
A method of producing a brazed joint between an aluminum or aluminum alloy component and another metallic component which comprises interposing between said components a body of a brazing alloy having a lower liquidus temperature than the solidus temperature of said components and a body of a flux consisting essentially of a mixture of fluoaluminate complexes containing Al, F, K, and Li atoms in said mixture, or a mixture of such complexes with aluminum fluoride, said flux having the Al, F, K, and Li atoms thereof present in amounts corresponding to the following proportions of the simple compounds: aluminum fluoride about 53-62% potassium fluoride about 35-44% lithium fluoride about 2-7% said flux containing up to about 2% entrained impurities, all percentages being by weight; and heating said assemblage to a temperature above the liquidus temperature of said brazing alloy and below the solidus temperature(s) of said components.
Claim 3
Dependent Claim
26 words
A method according to claim 1 wherein at least one of said components is an Al alloy containing Mg in an amount of 0.4-2% by weight.
Claim 4
Dependent Claim
27 words
A method according to claim 1 wherein the flux is applied in the form of an aqueous slurry in an amount of 3-15 gms/m 2 of solids.
Claim 5
Dependent Claim
30 words
A method according to claim 1 wherein the components are aluminum alloy castings and the brazing alloy is introduced as a preformed sheet member between the faces to be joined.
Claim 6
Dependent Claim
24 words
A method according to claim 1 wherein the assemblage is heated in an inert gas atmosphere having a water vapor content below 250 p.p.m.
Claim 7
Dependent Claim
23 words
A method according to claim 1, wherein said flux is a fused mixture of fluoride compounds containing Al, F, K, and Li atoms.
Claim 8
Dependent Claim
25 words
A method according to claim 1, wherein said flux is produced by reacting hydroxides of Al, K, and Li with hydroflouric acid in aqueous solution.
Claim 9
Dependent Claim
32 words
A method according to claim 1, wherein said flux comprises a homogeneous mixture of separately prepared fluoaluminate fluxes of which at least one is a ternary compound of Li, Al, and F.
Claim 10
Dependent Claim
16 words
A method according to claim 8, wherein said ternary compound is Li 3 AlF 6 .
Claim 11
Dependent Claim
22 words
A method according to claim 1, wherein at least one of said complexes is a ternary compound of Li, Al, and 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) | 1988-12-02 | 1989-06-03 | 1989-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-02 | 1993-06-03 | 1993-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-02 | 1997-06-03 | 1997-12-03 | $7700.00 | Window Closed / Lapsed |