US3673678A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluxless brazing process
Assignee: Abar Ipsen Industries Inc
•
Filing: 1970-05-08
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Granted: 1972-07-04
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Expires: 1990-05-08
Abstract
Abstract A process for the fluxless brazing of aluminum parts in a vacuum furnace in the presence of magnesium wherein a non-oxidizing gas is introduced into the evacuated furnace chamber to increase the pressure thereof and retard vaporization of at least part of the magnesium until just before the brazing temperature is reached.
Inventors
- 👤 Glenn T Moreau
- 👤 Irvin P Bielefeldt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 09:45
CPC Classifications
B; B23; B23K; B23K35/00; B23K35/22; B23K35/38; B23K1/00; B23K1/008; B23K35/24; B23K35/28; B23K35/286
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
40 words
A process as defined in claim 1 in which the chamber is re-evacuated to its highest order of vacuum after the brazing material has been heated to its liquid temperature but before heating the brazing material to the brazing temperature.
Claim 2
Dependent Claim
158 words
A process for brazing parts in a chamber without the use of flux comprising the steps of, forming an assembly of the parts and of a brazing material located at the areas of the parts to be joined, evacuating the chamber with the assembly therein to a high order of vacuum to establish a predetermined negative pressure within the chamber, heating the assembly within the evacuated chamber in the presence of a sacrificial metal capable of vaporizing at said pressure and at a temperature below the brazing temperature of said material, increasing the pressure in said chamber after commencing heating of said assembly and before reaching said brazing temperature thereby to retard vaporization of said sacrificial metal, decreasing the pressure in the chamber as the brazing temperature is approached thereby to vaporize said sacrificial metal, heating the assembly to the brazing temperature cooling the chamber, increasing the pressure therein, and thereafter removing the brazed assembly from the chamber.
Claim 3
Dependent Claim
28 words
A process as defined in claim 3 in which said assembly and said sacrificial metal are heated concurrently and are increased in temperature at substantially the same rate.
References Cited (Backward Citations)
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US3321828A
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US3373482A
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US3378914A
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US3370343A
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US3373483A
Cited
US3440712A
Cited
US3457630A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-04 | 1976-01-03 | 1976-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-04 | 1980-01-03 | 1980-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-04 | 1984-01-03 | 1984-07-04 | $7700.00 | Window Closed / Lapsed |