Method of manufacturing an assembly of brazed dissimilar metal components

• US 20020102431A1
• Filed: 11/06/2001
• Published: 08/01/2002
• Est. Priority Date: 05/19/2000
• Status: Active Grant

• Current Assignee: Dana Canada Corporation (Dana, Inc.)
• Original Assignee: Corus Aluminium Walzprodukte GmbH (Hindalco Industries Limited)
• Inventors: Wittebrood, Adrianus Jacobus, Wijenberg, Jacques Hubert Olga Joseph
• Granted Patent: US 6,503,640 B2
• Time in Patent Office: Days
• US Class Current: 428/658
• CPC Class Codes: B23K 1/008 Soldering within a furnace B23K1/012 takes precedence
• CPC Class Codes: B23K 1/19 taking account of the properties of the materials to be soldered
• CPC Class Codes: B23K 2103/10 Aluminium or alloys thereof
• CPC Class Codes: B23K 35/0238 layered
• CPC Class Codes: E04C 2002/3433 with dimples extending from both sides of the spacer sheet
• CPC Class Codes: E04C 2002/3455 with trapezoidal corrugations
• CPC Class Codes: E04C 2002/3466 with sinusoidal corrugations
• CPC Class Codes: E04C 2002/3472 with multiple layers of profiled spacer sheets
• CPC Class Codes: Y10S 428/926 Thickness of individual layer specified
• CPC Class Codes: Y10S 428/935 Electroplating
• CPC Class Codes: Y10T 428/12708 Sn-base component
• CPC Class Codes: Y10T 428/12736 Al-base component
• CPC Class Codes: Y10T 428/1275 Next to Group VIII or IB metal-base component
• CPC Class Codes: Y10T 428/12764 Next to Al-base component
• CPC Class Codes: Y10T 428/12771 Transition metal-base component
• CPC Class Codes: Y10T 428/12778 Alternative base metals from diverse categories
• CPC Class Codes: Y10T 428/12792 Zn-base component
• CPC Class Codes: Y10T 428/12944 Ni-base component

Abstract

Disclosed is a method of manufacturing an assembly of components joined by brazing, comprising the steps of:

(i) forming the components of which at least one is made from a multi-layered brazing sheet product, the multi-layered brazing sheet product comprising a core sheet (a) having on at least one surface of the core sheet an aluminium clad layer (b), the aluminium clad layer being made of an aluminium alloy comprising silicon in an amount in the range of 2 to 18% by weight, a layer (c) comprising nickel on the outer surface of the aluminium clad layer, and a layer (d) comprising zinc or tin as a bonding layer between the outer surface of the aluminium clad layer and the layer comprising nickel;

(ii) forming at least one other component of a metal dissimilar to the core sheet of the multi-layered brazing sheet product and selected from the group consisting of titanium, plated titanium, coated titanium, bronze, brass, stainless steel, plated stainless steel, coated stainless steel, low-carbon steel, plated low-carbon steel, coated low-carbon steel, high-strength steel, coated high-strength steel, and plated high-strength steel;

(iii) assembling the respective components into an assembly such that the layer (c) comprising nickel of the multi-layered brazing sheet product faces in part or in whole the at least one other component of a metal dissimilar to the core sheet of the multi-layered brazing sheet product;

(iv) brazing the assembly under a vacuum or in an inert atmosphere in the absence of a brazing-flux at elevated temperature for a period long enough for melting and spreading of the aluminium clad layer and all layers exterior thereto;

(v) cooling the brazed assembly.

The invention further relates to an assembly manufactured using the method of this invention.

Claims

1. A method of manufacturing an assembly of components joined by brazing, comprising the steps of:

(i) forming said components of which at least one is made from a multi-layered brazing sheet product, the multi-layered brazing sheet product comprising a core sheet (a) having on at least one surface of said core sheet (a) an aluminium clad layer (b), the aluminium clad layer (b) being made of an aluminium alloy comprising silicon in an amount in the range of 2 to 18% by weight, a layer (c) comprising nickel on an outer surface of said aluminium clad layer, and a layer (d) comprising zinc or tin as a bonding layer between said outer surface of said aluminium clad layer (b) and said layer (c) comprising nickel;

(ii) forming at least one other component of a metal dissimilar to the core sheet of the multi-layered brazing sheet product and selected from the group consisting of titanium, plated titanium, coated titanium, bronze, brass, stainless steel, plated stainless steel, coated stainless steel, nickel, nickel alloy, low-carbon steel, plated low-carbon steel, coated low-carbon steel, high-strength steel, coated high-strength steel, and plated high-strength steel;

(iii) assembling the respective components into an assembly such that the layer (c) comprising nickel of the multi-layered brazing sheet product faces in part or in whole the at least one other component of a metal dissimilar to the core sheet of the multi-layered brazing sheet product;

(iv) brazing the assembly under a vacuum or in an inert atmosphere in the absence of a brazing-flux at elevated temperature for a period long enough for melting and spreading of the aluminium clad layer (b) and all layers exterior thereto;

(v) cooling the brazed assembly.

2. The method according to claim 1, wherein said aluminium clad layer (b) has discrete silicon-rich particles exposed at said outer surface thereof, and said layer comprising nickel is bonded to said silicon-rich particles and to the areas of said outer surface between said silicon-rich particles, so as to form a continuous layer on said outer surface.

3. The method according to claim 1, wherein said bonding layer (d) is applied by a direct zinc-plating treatment or a zincate treatment or a stannate treatment.

4. The method according to claim 3, wherein said bonding layer (d) is applied by an immersion zincate treatment or an immersion stannate treatment.

5. The method according to claim 1, wherein said bonding layer (d) has a thickness of not more than 0.5 μ

m.

6. The method according to claim 5, wherein said bonding layer (d) has a thickness in the range of 20 to 150 nm.

7. The method according to claim 1, wherein the layer (c) comprising nickel further comprises bismuth in a range of at most 5% by weight.

8. Method of manufacturing an assembly of components joined by brazing, comprising the steps of:

(i) forming said components of which at least one is made from a multi-layered brazing sheet product, the multi-layered brazing sheet product comprising a core sheet (a) having on at least one surface of said core sheet an aluminium clad layer (b), the aluminium clad layer being made of an aluminium alloy comprising silicon in an amount in the range of 2 to 18% by weight, and a layer (c) on the outer surface of said aluminium clad layer, the layer (c) comprising nickel and further at least bismuth in a range of at most 5% by weight;

(ii) forming at least one other component of a metal dissimilar to the core sheet of the multi-layered brazing sheet product and selected from the group consisting of titanium, plated titanium, coated titanium, bronze, brass, stainless steel, plated stainless steel, coated stainless steel, nickel, nickel alloy, low-carbon steel, plated low-carbon steel, coated low-carbon steel, high-strength steel, coated high-strength steel, and plated high-strength steel;

(iii) assembling the respective components into an assembly such that the layer (c) comprising nickel of the multi-layered brazing sheet faces in part or in whole the at least one other component of a metal dissimilar to the core sheet of the multi-layered brazing sheet product;

(iv) brazing the assembly under a vacuum or in an inert atmosphere in the absence of a brazing-flux at elevated temperature for a period long enough for melting and spreading of the aluminium clad layer (b) and all layers exterior thereto;

(v) cooling the brazed assembly.

9. The method according to claim 1, wherein said layer (c) comprising nickel is applied by electroplating.

10. The method according to claim 1, wherein said layer (c) comprising nickel, further comprises bismuth in a range of up to 3% by weight.

11. The method according to claim 1, wherein said layer (c) comprising nickel has a thickness of not more than 2.0 μ

m.

12. The method according to claim 1, wherein said layer (c) comprising nickel is deposited by electroplating both nickel and bismuth using an aqueous bath comprising a nickel-ion concentration in the range of 10 to 100 g/l and a bismuth-ion concentration in the range of 0.01 to 10 g/l.

13. The method according to claim 1, wherein the layer (c) comprising nickel is essentially lead-free.

14. The method according to claim 1, wherein the core sheet (a) of the multi-layered brazing sheet product is of an aluminium alloy.

15. The method according to claim 14, wherein the core sheet (a) of the multi-layered brazing sheet product is of an aluminium alloy selected from the group consisting of AA3000, AA5000, and AA6000-series aluminium alloys.

16. The method according to claim 1, wherein said bonding layer (d) has a thickness of not more than 0.3 μ

m.

17. The method according to claim 1, wherein said layer (c) comprising nickel, also comprises nickel and bismuth, and is applied by electroplating.

18. The method according to claim 1, wherein said layer (c) comprising nickel, further comprises bismuth in a range of up to 1% by weight.

19. The method according to claim 1, wherein said layer (c) comprising nickel, further comprises bismuth in a range of 0.01 to 0.05% by weight.

20. The method according to claim 1, wherein said layer (c) comprising nickel has a thickness of not more than 1.0 μ

m.

21. An assembly of components joined by brazing manufactured by the method according to claim 1.

22. An assembly according to claim 21, wherein the assembly is an automotive heat exchanger.

23. An assembly according to claim 21, wherein the assembly is a fuel cell.

24. An assembly according to claim 21, wherein the assembly is a proton exchange membrane fuel cell.

25. An assembly of components joined by brazing manufactured by the method according to claim 8.

26. An assembly according to claim 25, wherein the assembly is an automotive heat exchanger.

27. An assembly according to claim 25, wherein the assembly is a fuel cell.

28. An assembly according to claim 25, wherein the assembly is a proton exchange membrane fuel cell.