# US 11,298,779 B2 · Brazing sheet and manufacturing method thereof

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- Number: US 11,298,779 B2
- Document ID: US11298779B2
- Status: Granted
- Kind: B2
- Application number: 16/758,238
- Filed: 2018-11-06
- Published: 2020-10-29
- Granted: 2022-04-12
- Earliest claimed: 2017-11-08
- Assignees: Uacj Corporation
- Applicants: UACJ Corporation
- Inventors: Yasunaga Itoh
- Web page: https://patentgrep.com/patent/US11298779B2

## CPC

- B23K 35/0233: {Sheets or foils (B23K35/0244 takes precedence)}
- C22C 21/10: with zinc as the next major constituent
- B23K 35/0238: {layered}
- B23K 35/286: {Al as the principal constituent}
- B32B 15/016: {all layers being formed of aluminium or aluminium alloys}
- C22C 21/00: Alloys based on aluminium
- C22C 21/02: with silicon as the next major constituent
- C22C 21/06: with magnesium as the next major constituent
- B23K 2103/10: Aluminium or alloys thereof
- Y10T 428/12764: Next to Al-base component
- 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)
- B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A brazing sheet brazing suitable for brazing performed in an inert gas atmosphere or in a vacuum without using a flux has a three-layer composition. An aluminum alloy core material contains Mg: 1.3 mass % or less. An aluminum alloy intermediate material is layered on the core material and contains Mg: 0.40-6.0 mass %. An aluminum alloy filler material is layered on the intermediate material and contains Si: 6.0-13.0 mass %, Bi: 0.0040-0.070 mass %, and Mg: 0.050-0.10 mass %.

## Claims

### Claim 1

A brazing sheet usable in brazing performed in an inert-gas atmosphere or in a vacuum without using a flux, comprising:
a core material having a chemical composition containing Mg: 1.3 mass % or less, the remainder being Al and unavoidable impurities;
an intermediate material having a chemical composition containing Mg: 0.40 mass % or more and 6.0 mass % or less, the remainder being Al and unavoidable impurities, and being layered on the core material; and
a filler material having a chemical composition containing Si: 6.0 mass % or more and 13.0 mass % or less, Bi: 0.0040 mass % or more and 0.070 mass % or less, and Mg: 0.050 mass % or more and less than 0.10 mass %, the remainder being Al and unavoidable impurities, and being layered on the intermediate material.

### Claim 2 (depends on 1)

The brazing sheet according to claim 1, wherein the intermediate material further contains Si: 1.0 mass % or more and 13.0 mass % or less.

### Claim 3 (depends on 1)

The brazing sheet according to claim 1, wherein the core material further contains one or two or more elements selected from the group consisting of: Mn: 0.30 mass % or more and 2.0 mass % or less, Si: 0.10 mass % or more and 1.0 mass % or less, Fe: less than 1.0 mass %, Cu: 1.0 mass % or less, Ti: less than 0.10 mass %, Zr: less than 0.30 mass %, and Cr: less than 0.30 mass %.

### Claim 4 (depends on 1)

The brazing sheet according to claim 1, wherein the Mg content in the core material is less than 1.0 mass %.

### Claim 5 (depends on 4)

The brazing sheet according to claim 4, wherein the Bi content in the filler material is less than 0.030 mass %.

### Claim 6 (depends on 3)

The brazing sheet according to claim 3, wherein the Mg content in the core material is less than 1.0 mass %.

### Claim 7 (depends on 6)

The brazing sheet according to claim 6, wherein the Bi content in the filler material is less than 0.030 mass %.

### Claim 8 (depends on 7)

The brazing sheet according to claim 7, wherein the intermediate material further contains Si: 1.0-13.0 mass %.

### Claim 9 (depends on 7)

The brazing sheet according to claim 7, wherein the intermediate material further contains Zn: 0.9-6.0 mass %.

### Claim 10 (depends on 9)

The brazing sheet according to claim 9, wherein the intermediate material further contains Cu: 0.20-2.0 mass %.

### Claim 11 (depends on 7)

The brazing sheet according to claim 7, wherein the intermediate material directly contacts the core material and the filler material directly contacts the intermediate material.

### Claim 12 (depends on 1)

The brazing sheet according to claim 1, wherein:
the Mg content in the intermediate material is 0.20-1.0 mass %, and
the Bi content in the filler material is 0.0040-0.030 mass %.

### Claim 13 (depends on 1)

The brazing sheet according to claim 1, wherein the intermediate material directly contacts the core material and the filler material directly contacts the intermediate material.

### Claim 14 (depends on 1)

A method of manufacturing the brazing sheet according to claim 1, comprising:
preparing a cladding mass by superposing a core-material mass having the chemical composition of the core material according to claim 1, an intermediate-material mass having the chemical composition of the intermediate material according to claim 1, and a filler-material mass having the chemical composition of the filler material according to claim 1;
preparing a clad sheet by rolling the cladding mass; and
etching the clad sheet using an acid or an alkali.

### Claim 15 (depends on 14)

The method of manufacturing the brazing sheet according to claim 14, comprising:
after the etching has been performed, applying 500 mg/cm′ or more of a protective oil, which has a decomposition temperature that is 200-380° C. in an inert gas atmosphere, to a surface of the brazing sheet.

### Claim 16

A brazing sheet, comprising:
a core composed of an aluminum alloy comprising 0-1.3 mass % Mg;
an intermediate material layered on the core and being composed of an aluminum alloy comprising 0.4-6.0 mass % Mg; and
a filler layered on the intermediate material and being composed of an aluminum alloy comprising 6.0-13.0 mass % Si, 0.0040-0.070 mass % Bi, and 0.050-0.10 mass % Mg.

### Claim 17 (depends on 16)

The brazing sheet according to claim 16, wherein:
the Mg content in the core material is less than 1.0 mass %;
the Bi content in the filler material is less than 0.030 mass %; and
the filler further contains Fe: 0.18-0.50 mass %.

### Claim 18 (depends on 17)

The brazing sheet according to claim 17, wherein the core material further contains: Mn: 0.30-2.0 mass %, Si: 0.10-1.0 mass %, Fe: 0.6-1.0 mass %, and Cu: 0.15-1.0 mass %.

### Claim 19 (depends on 18)

The brazing sheet according to claim 18, wherein:
a first surface of the intermediate material directly contacts the core;
the filler directly contacts a second surface of the intermediate material that is opposite of the first surface of the intermediate material such that the intermediate material is sandwiched between the core and the filler; and
the filler is an outermost layer of the brazing sheet.

### Claim 20

A brazing sheet usable in brazing performed in an inert-gas atmosphere or in a vacuum without using a flux, comprising:
a core material having a chemical composition containing Mg: 1.0 mass % or less and one or more elements selected from the group consisting of: Mn: 0.30-2.0 mass %, Si: 0.10-1.0 mass %, Fe: less than 1.0 mass %, Cu: 1.0 mass % or less, Ti: less than 0.10 mass %, Zr: less than 0.30 mass %, and Cr: less than 0.30 mass %, the remainder being Al and unavoidable impurities;
an intermediate material layered on the core material and having a chemical composition containing Mg: 0.40-6.0 mass % and Be: 0.050-0.20 mass %, the remainder being Al and unavoidable impurities; and
a filler material layered on the intermediate material and having a chemical composition containing Si: 6.0-13.0 mass %, Bi: 0.0040-0.030 mass %, and Mg: 0.050-0.10 mass %, the remainder being Al and unavoidable impurities.