US3951328A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Joining of metal surfaces
Assignee: Alcan Research and Development Ltd
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Filing: 1975-10-06
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Granted: 1976-04-20
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Expires: 1995-10-06
Abstract
Abstract In methods of joining metal surfaces involving heating to a temperature above about 560°C, the use of a flux comprising a mixture of potassium fluoaluminates. Particularly for brazing aluminum, a flux consisting essentially of potassium fluoaluminate complexes (e.g. KAlF 4 and K 3 AlF 6 ) may be employed, having a composition corresponding to an AlF 3 /KF ratio, in parts by weight, between about 65:35 and about 45:55. The flux is essentially free of unreacted potassium fluoride and may be in divided solid form.
Inventors
- 👤 Eric Robert Wallace
- 👤 Ernest William Dewing
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 22:24
CPC Classifications
B; B23; B23K; B23K35/00; B23K35/22; B23K35/24; B23K35/28; B23K35/286; B23K35/36; B23K35/3601; B23K35/3603; B23K35/3605
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
122 words
A method of joining by brazing surfaces of metal selected from the class consisting of aluminum and alloys thereof with an aluminum brazing alloy having a melting point lower than that of metal of the surfaces to be joined, comprising: a. disposing, for contact, between the surfaces, with exposed metal including a body of the brazing alloy which is to serve for joining the surfaces, a flux comprising a mixture of potassium fluoaluminate complexes and essentially free of unreacted potassium fluoride; b. heating the brazing alloy body and flux, in juxtaposed relation to the surfaces to be joined, to a temperature above the brazing alloy melting point for joining the surfaces; and c. then allowing said body and said surfaces to cool.
Claim 2
Independent Claim
122 words
A method of joining by brazing surfaces of metal selected from the class consisting of aluminum and alloys thereof with an aluminum brazing alloy having a melting point lower than that of metal of the surfaces to be joined, comprising: a. disposing, for contact, between the surfaces, with exposed metal including a body of the brazing alloy which is to serve for joining the surfaces, a flux comprising a mixture of potassium fluoaluminate complexes and essentially free of unreacted potassium fluoride; b. heating the brazing alloy body and flux, in juxtaposed relation to the surfaces to be joined, to a temperature above the brazing alloy melting point for joining the surfaces; and c. then allowing said body and said surfaces to cool.
Claim 3
Dependent Claim
51 words
A method according to claim 1, wherein the flux-providing step comprises providing a flux consisting essentially of a mixture of said potassium fluoaluminate complexes essentially free of unreacted potassium fluoride and having a composition corresponding to an aluminum fluoride/potassium fluoride ratio, in parts by weight, between about 65:35 and about 45:55.
Claim 4
Dependent Claim
26 words
A method according to claim 1, wherein the flux-providing step comprises providing a flux as aforesaid wherein said ratio is between about 60:40 and about 50:50.
Claim 5
Dependent Claim
30 words
A method according to claim 3, wherein the disposing step comprises disposing a flux as aforesaid consisting essentially of a mixture of KAlF 4 and K 3 AlF 6 .
Claim 6
Dependent Claim
21 words
A method according to claim 2, wherein the flux-providing step comprises providing a flux as aforesaid in finely divided solid form.
Claim 7
Dependent Claim
33 words
A method according to claim 5, wherein the flux-providing step comprises providing a flux as aforesaid in finely divided solid form having a maximum particle size of not more than about 1/16 inch.
Claim 8
Dependent Claim
18 words
A method according to claim 6, wherein said maximum particle size is not more than about 150 microns.
Claim 9
Dependent Claim
26 words
A method according to claim 6, wherein the flux-providing step comprises providing the flux in dispersion in a vehicle in which the flux is substantially insoluble.
Claim 10
Dependent Claim
45 words
A method according to claim 2, further including the steps of preparing the flux by a. establishing a dry mixture of divided solid aluminum fluoride and potassium fluoride in proportions providing said ratio, and b. heating the last-mentioned mixture for effecting substantially complete fusion thereof.
Claim 11
Dependent Claim
44 words
A method according to claim 2, further including the step of preparing the flux by combining separately prepared K 3 AlF 6 and KAlF 4 to provide a mixture thereof, essentially free of unreacted potassium fluoride, and having a composition corresponding to said ratio.
Claim 12
Dependent Claim
24 words
A method according to claim 1, wherein said flux has a composition corresponding to a substantially eutectic mixture of aluminum fluoride and potassium fluoride.
Claim 13
Dependent Claim
41 words
A method according to claim 1, wherein said mixture of potassium fluoaluminate complexes consists essentially of a mixture of at least two compounds selected from the class consisting of AlF 3 , K 3 AlF 6 , and KAlF 4 .
Claim 14
Dependent Claim
19 words
A method according to claim 1, wherein said mixture of potassium fluoaluminate complexes consists essentially of KAlF 4 .
Claim 15
Independent Claim
145 words
A method of joining by brazing surfaces of metal selected from the class consisting of aluminum and alloys thereof with an aluminum brazing alloy having a melting point lower than that of metal of the surfaces to be joined, said method comprising the steps of a. disposing, for contact, between the surfaces, with exposed metal including a body of the brazing alloy which is to serve for joining the surfaces, a layer of a flux in finely divided solid form dispersed in water as a slurry, said flux consisting essentially of a mixture of potassium fluoaluminate complexes essentially free of unreacted potassium fluoride; b. heating the brazing alloy ahd flux layer, in juxtaposed relation to the surfaces to be joined, to a temperature above the brazing alloy melting point for joining the surfaces; and c. then allowing the brazing alloy and the surfaces to cool.
Claim 16
Independent Claim
145 words
A method of joining by brazing surfaces of metal selected from the class consisting of aluminum and alloys thereof with an aluminum brazing alloy having a melting point lower than that of metal of the surfaces to be joined, said method comprising the steps of a. disposing, for contact, between the surfaces, with exposed metal including a body of the brazing alloy which is to serve for joining the surfaces, a layer of a flux in finely divided solid form dispersed in water as a slurry, said flux consisting essentially of a mixture of potassium fluoaluminate complexes essentially free of unreacted potassium fluoride; b. heating the brazing alloy ahd flux layer, in juxtaposed relation to the surfaces to be joined, to a temperature above the brazing alloy melting point for joining the surfaces; and c. then allowing the brazing alloy and the surfaces to cool.
Claim 17
Dependent Claim
39 words
A method according to claim 14, wherein the flux-providing step comprises providing a layer of a flux as aforesaid having a composition corresponding to an aluminum fluoride/potassium fluoride ratio, in parts by weight, between about 60:40 and about 50:50.
Claim 18
Dependent Claim
45 words
A method according to claim 15, wherein said body of brazing alloy is formed as a cladding on the other of the surfaces to be joined, and wherein the flux-providing step comprises disposing the slurry in proximate relation to said one surface and said cladding.
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) | 1979-04-20 | 1979-10-20 | 1980-04-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-04-20 | 1983-10-20 | 1984-04-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-04-20 | 1987-10-20 | 1988-04-20 | $7700.00 | Window Closed / Lapsed |