# US 6,294,272 B2 · Aluminium alloy for use as core material in brazing sheet

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- Number: US 6,294,272 B2
- Document ID: US6294272B2
- Status: Granted
- Kind: B2
- Application number: 09/202,931
- Filed: 1999-03-24
- Published: 2001-08-02
- Granted: 2001-09-25
- Earliest claimed: 1996-11-04
- Assignees: Corus Aluminium Walzprodukte GmbH
- Inventors: Jeroen Andreas Helmuth Söntgerath; Achim Bürger; Klaus Vieregge
- Web page: https://patentgrep.com/patent/US6294272B2

## CPC

- F28F 21/084: {from aluminium or aluminium alloys}
- B23K 35/0238: {layered}
- C22C 21/00: Alloys based on aluminium
- B23K 35/286: {Al as the principal constituent}
- B23K 2103/10: Aluminium or alloys thereof
- Y10T 428/12764: Next to Al-base component
- F28F: DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION (water and air traps, air venting F16)
- B23K: SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- C22C: ALLOYS (treatment of alloys C21D, C22F)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

An aluminium alloy for use as a core material in brazing sheet, comprising, in weight %: Mn 0.7-1.5, Cu 0.6-1.0, Fe not more than 0.4, Si less than 0.1, Mg 0.05-0.8, Ti 0.02-0.3, Cr 0.1-0.25, Zr 0.1-0.2, balance Al and unavoidable impurities, wherein 0.20<(Cr+Zr)≦0.4, the alloy being capable of obtaining in the post-brazing state 0.2% yield strength of at least 65 MPa and having a corrosion life of more than 11 days in a SWAAT test without perforations in accordance with ASTM G-85.

## Claims

### Claim 1

A brazing sheet comprising an aluminium alloy for use as a core material in the brazing sheet, the core material having a high corrosion resistance in the absence of a sacrificial anode coating layer, comprising, in weight %:
Mn 0.7-1.5 Cu 0.6-1.0 Fe not more than 0.4 Si at most 0.08 Mg 0.05-0.8 Ti 0.02-0.09 Cr 0.1-0.25 Zr 0.1-0.2
wherein 0.20<(Cr+Zr)≦0.4,
wherein the core has no coating layer for acting as a sacrificial anode in contact with water, the alloy being capable of obtaining in the post-brazing state 0.2% yield strength of at least 65 MPa and having a corrosion life of more than 11 days in a SWAAT test without perforations in accordance with ASTM G-85.

### Claim 2 (depends on 1)

A brazing sheet according to claim 1, wherein the corrosion life in said SWAAT test is at least 16 days.

### Claim 3 (depends on 1)

A brazing sheet according to claim 1, wherein the Cu content is 0.7-1.0 wt. %.

### Claim 4 (depends on 1)

A brazing sheet according to claim 1, wherein the Ti content is 0.08-0.09 wt. %.

### Claim 5 (depends on 1)

A brazing sheet according to claim 1, wherein the Mn content is 0.8-1.2 wt. %.

### Claim 6 (depends on 1)

A brazing sheet according to claim 1, wherein said core material has a clad layer on at least one side thereof.

### Claim 7 (depends on 1)

A method of making a brazing sheet according to claim 1, comprising providing said alloy as core material of the brazing sheet in a brazed assembly, applying a clad layer to the core material.

### Claim 8 (depends on 7)

A method of use according to claim 7, wherein the core material contacts at least one said clad layer of a low melting point brazing alloy.

### Claim 9 (depends on 1)

A brazed assembly comprising at least two members bonded together by means of a brazing alloy, at least one of said members being of sheet material comprising a brazing sheet according to claim 1.

### Claim 10

A brazing sheet comprising an aluminium alloy for use as a core material in the brazing sheet, the core material having a high corrosion resistance in the absence of a sacrificial anode coating layer, consisting of, in weight %:
Mn 0.7-1.5 Cu 0.6-1.0 Fe not more than 0.4 Si at most 0.08 Mg 0.05-0.8 Ti 0.02-0.09 Cr 0.1-0.25 Zr 0.1-0.2 balance Al and unavoidable impurities
wherein 0.20<(Cr+Zr)≦0.4,
wherein the core has no coating layer acting as a sacrificial anode in contact with water, the alloy being capable of obtaining in the post-brazing state 0.2% yield strength of at least 65 MPa and having a corrosion life of more than 11 days in a SWAAT test without perforations in accordance with ASTM G-85.