Patent US4831701A successfully refreshed from Google Patents.
US4831701A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making a corrosion resistant aluminum heat exchanger using a particulate flux
Assignee: Sanden Corp
•
Filing: 1986-02-12
•
Granted: 1989-05-23
•
Expires: 2006-02-12
Abstract
Abstract A method of treating a heat exchanger made of aluminum or an aluminum alloy comprising applying onto the surface of the aluminum heat exchanger a noncorrosive flux having a flux core with an outer coating of zinc or a zinc alloy formed by vacuum vapor deposition or ion plating, and then heating the resulting heat exchanger to effect brazing. A diffused zinc layer forms on the surface of the heat exchanger and protects it from corrosion, in particular, from electrolytic corrosion.
Inventors
- 👤 Ishii Yutaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 21:40
CPC Classifications
F; F28; F28F; F28F19/00; F28F19/02; F28F19/06; B; B23; B23K; B23K1/00; B23K1/0008; B23K1/0012; B23K35/00; B23K35/02; B23K35/0222; B23K35/0244; B23K35/22; B23K35/36; B23K35/3601; B23K35/3603; B23K35/3605; B23P; B23P15/00; B23P15/26; C; C23; C23C; C23C26/00; F28D; F28D1/00; F28D1/02; F28D1/04; F28D1/047; F28D1/0477; F28D1/0478; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/4935; Y10T29/49393
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
77 words
A method of treating an aluminum heat exchanger to make it corrosion resistant comprising (a) applying a noncorrosive particulate flux onto the surface of the aluminum heat exchanger, said noncorrosive particulate flux comprising a flux core with an outer coating of zinc or a zinc alloy; and (b) heating the heat exchanger to effect brazing and cause the zinc or zinc alloy to diffuse into the surface of the heat exchanger and form a diffused zinc layer.
Claim 2
Independent Claim
77 words
A method of treating an aluminum heat exchanger to make it corrosion resistant comprising (a) applying a noncorrosive particulate flux onto the surface of the aluminum heat exchanger, said noncorrosive particulate flux comprising a flux core with an outer coating of zinc or a zinc alloy; and (b) heating the heat exchanger to effect brazing and cause the zinc or zinc alloy to diffuse into the surface of the heat exchanger and form a diffused zinc layer.
Claim 3
Dependent Claim
18 words
The method of claim 1, wherein said flux core consists essentially of a mixture of potassium fluoroaluminate complexes.
Claim 4
Dependent Claim
16 words
The method of claim 1, wherein said diffused zinc layer has maximum thickness of about 200μ.
Claim 5
Dependent Claim
29 words
The method of claim 1, wherein said diffused zinc layer has a zinc density at the surface of the heat exchanger of from about 0.2 to 2.0% (by weight).
Claim 6
Dependent Claim
18 words
The method of claim 2, wherein said flux core comprises a mixture of potassium tetrafluoroaluminate and potassium hexafluoroaluminate.
Claim 7
Dependent Claim
23 words
The method of claim 1, wherein said flux core is in the form of particles having a maximum diameter of about 100 mesh.
Claim 8
Dependent Claim
23 words
The method of claim 6 wherein said outer coating of zinc or a zinc alloy has a thickness betwen about 30μ and 100μ.
Claim 9
Dependent Claim
17 words
The method of claim 1, wherein said heat exchanger is a condenser of an automotive air conditioner.
References Cited (Backward Citations)
SU334031A1
Cited
US32309A
Cited
US2565477A
Cited
US2837450A
Cited
US3440712A
Cited
US3703254A
Cited
US3951328A
Cited
SU471980A1
Cited
US3971501A
Cited
JPS5333836A
Cited
JPS5433836A
Cited
US4358485A
Cited
JPS56160869A
Cited
JPS5722868A
Cited
JPS59218263A
Cited
JPS59229280A
Cited
USRE32309E
Cited
US4579605A
Cited
US4619715A
Cited
JPH103958A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-05-22 | 1992-11-21 | 1993-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-22 | 1996-11-21 | 1997-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-22 | 2000-11-21 | 2001-05-23 | $7700.00 | Window Closed / Lapsed |