Aluminum alloy brazing sheet for heat exchanger

• US 8,227,091 B2
• Filed: 12/18/2007
• Issued: 07/24/2012
• Est. Priority Date: 12/27/2006
• Status: Active Grant

• Current Assignee: DENSO Corporation, Klaus Schmidt
• Original Assignee: DENSO Corporation, Kobe Steel Limited
• Inventors: Ueda, Toshiki, Tsuruno, Akihiro, Koshigoe, Fumihiro, Okazaki, Keiichi, Negura, Kenji, Nagaya, Takahiko
• Primary Examiner(s): BOYKIN, TERRESSA M
• Application Number:
  US12/519,023
• Publication Number:
  US 20100112370A1
• Time in Patent Office: 1,680 Days
• Field of Search: 428/411.1, 428/457, 428/645, 228/262.5, 228/262.51
• US Class Current: 428/654
• CPC Class Codes: B23K 35/0238 layered
• CPC Class Codes: B23K 35/22 characterised by the composition or nature of the material
• CPC Class Codes: B23K 35/28 with the principal constituent melting at less than 950 degrees C
• CPC Class Codes: B23K 35/40 Making wire or rods for soldering or welding processes involving a single technical art, see the relevant subclasses, e.g. B05D, B21C
• CPC Class Codes: B32B 15/016 all layers being formed of aluminium or aluminium alloys
• CPC Class Codes: C22C 21/00 Alloys based on aluminium
• CPC Class Codes: C22C 21/02 with silicon as the next major constituent
• CPC Class Codes: C22C 21/10 with zinc as the next major constituent
• CPC Class Codes: C22C 21/14 with silicon
• CPC Class Codes: C22F 1/053 of alloys with zinc as the next major constituent
• CPC Class Codes: F28F 19/06 of metal
• CPC Class Codes: F28F 21/089 Coatings, claddings or bonding layers made from metals or metal alloys F28F19/06 takes precedence
• CPC Class Codes: Y10T 428/12222 Shaped configuration for melting [e.g., package, etc.]
• CPC Class Codes: Y10T 428/12764 Next to Al-base component
• CPC Class Codes: Y10T 428/31504 Composite [nonstructural laminate]
• CPC Class Codes: Y10T 428/31678 Of metal

Abstract

Disclosed is an aluminum alloy brazing sheet for heat exchangers, which has high strength after brazing, high corrosion resistance and excellent brazability. Specifically disclosed is an aluminum alloy brazing sheet (1a) for heat exchangers comprising a core member (2), a sacrificial member (3) formed on one side of the core member (2), and a brazing filler metal (4) formed on the other side of the core member (2) and composed of an Al—Si alloy. The sacrificial member (3) contains 0.03-0.30% by mass of Fe, 0.01-0.40% by mass of Mn, 0.4-1.4% by mass of Si, 2.0-5.5% by mass of Zn, not more than 0.05% by mass of Mg and the balance of Al and unavoidable impurities. In addition, the sacrificial member (3) has a crystal grain size of 100-400 & mgr;m after 5-minute heat treatment at 600 & ring;C during the brazing.

Claims

1. An aluminum alloy brazing sheet, comprising a core material, a sacrificial anode material formed in one face side of the core material, and a brazing filler metal made of an Al-Si based alloy formed in the other face side of the core material, wherein the sacrificial anode material has a composition comprising Fe:

0.03 to 0.30% by mass, Mn;

0.01 to 0.40% by mass, Si;

larger than 0.4 and 1.4% or less by mass, Zn 2.0 to 5.5% by mass, Mg;

0.05% by mass or less, and Al and inevitable impurities and wherein the sacrificial anode material after a heat treatment of 600°

C.×

5 minutes has a crystal grain size in a range of from 100 to 400 μ

m.

2. The aluminum alloy brazing sheet according to claim 1, wherein the crystal grain size is in a range of from 120 to 380 μ

m.

3. The aluminum alloy brazing sheet according to claim 1, wherein a thickness of the sacrificial anode material is in a range of from 30 to 55 μ

m.

4. The aluminum alloy brazing sheet according to claim 1, wherein the brazing filler metal has a composition comprising Si in a range of from 7 to 12% by mass.

5. The aluminum alloy brazing sheet according to claim 1, wherein the aluminum alloy brazing sheet further comprises an intermediate material.

6. The aluminum alloy brazing sheet according to claim 5, wherein the intermediate material is placed between the core material and the brazing filler metal.

7. The aluminum alloy brazing sheet according to claim 1, wherein the composition of the sacrificial anode material comprises Si in a range of from 0.45 to 1.4% by mass.

8. The aluminum alloy brazing sheet according to claim 1, wherein the core material has a composition comprising Cu in a range of from 0.5 to 12% by mass, Mn in a range of from 0.6 to 1.9% by mass, Si in a range of from 0.5 to 1.4%, at least one of Cr and Ti in a range of from 0.05 to 0.3% by mass, Al and inevitable impurities.

9. The aluminum alloy brazing sheet according to claim 1, wherein the composition of the sacrificial anode material consists of Fe:

0.03 to 0.30% by mass, Mn;

0.01 to 0.40% by mass, Si;

larger than 0.4 and 1.4% or less by mass, Zn 2.0 to 5.5% by mass, Mg;

0. 05% by mass or less, and Al and inevitable impurities.