# US 10,307,870 B2 · Aluminum alloy brazing sheet and method for producing the same

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- Number: US 10,307,870 B2
- Document ID: US10307870B2
- Status: Granted
- Kind: B2
- Application number: 15/428,775
- Filed: 2017-02-09
- Published: 2017-06-01
- Granted: 2019-06-04
- Earliest claimed: 2013-07-31
- Assignees: Uacj Corporation
- Applicants: Uacj Corporation
- Inventors: Yasunaga Itoh; Tomoki Yamayoshi
- Web page: https://patentgrep.com/patent/US10307870B2

## CPC

- B23K 35/286: {Al as the principal constituent}
- B23K 1/00: Soldering, e.g. brazing, or unsoldering (B23K3/00 takes precedence)
- B23K 1/0012: {Brazing of heat exchangers}
- B23K 1/20: Preliminary treatment of work or areas to be soldered, e.g. in respect of a galvanic coating
- B23K 1/206: {Cleaning}
- B23K 35/00: Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
- B23K 35/0238: {layered}
- B23K 35/38: Selection of media, e.g. special atmospheres for surrounding the working area
- 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
- F28F 21/084: {from aluminium or aluminium alloys}
- F28F 21/089: {Coatings, claddings or bonding layers made from metals or metal alloys (F28F19/06 takes precedence)}
- B23K 2101/14: Heat exchangers
- 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
- B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- C22C: ALLOYS (treatment of alloys C21D, C22F)
- F28F: DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION (water and air traps, air venting F16)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

An aluminum alloy brazing sheet achieves a stable brazability equal to by brazing using a flux, even if an etching treatment is not performed on the brazing site. The aluminum alloy brazing sheet is used to braze aluminum in an inert gas atmosphere without using a flux and includes a core material and a filler metal, one side or each side of the core material being clad with the filler metal, the core material being formed of an aluminum alloy that includes 0.2 to 1.3 mass % of Mg, the filler metal including 6 to 13 mass % of Si and 0.004 to 0.1 mass % of Li, with the balance being aluminum and unavoidable impurities, a surface oxide film having been removed from the brazing sheet, and an oil solution that decomposes when heated at 380° C. or less in an inert gas having been applied to the brazing sheet.

## Claims

### Claim 1

An aluminum alloy brazing sheet for brazing aluminum in an inert gas atmosphere without using flux, the brazing sheet comprising a core material and a filler metal, a first side or the first side and a side opposite to the first side of the core material being clad with the filler metal, the core material being formed of an aluminum alloy that includes 0.2 to 1.3 mass % of Mg, with the balance being aluminum and unavoidable impurities, the filler metal including 6 to 13 mass % of Si and 0.004 to 0.1 mass % of Li, with the balance being aluminum and unavoidable impurities, a surface oxide film having been removed from the brazing sheet, and an oil solution that decomposes when heated at 380° C. or less in an inert gas having been applied to the brazing sheet, wherein the decomposition temperature of the oil solution is 200-380° C. and the application amount of the oil solution is at least 500 mg/m2.

### Claim 2 (depends on 1)

The aluminum alloy brazing sheet according to claim 1, wherein the aluminum alloy that forms the core material includes 0.2 to 1.3 mass % of Mg, and one or more elements from among 0.5 to 1.8 mass % of Mn, 1.0 mass % or less of Si, 1.0 mass % or less of Fe, 0.5 mass % or less of Cu, 0.5 mass % or less of Zn, 0.2 mass % or less of Ti, and 0.5 mass % or less of Zr, with the balance being aluminum and unavoidable impurities.

### Claim 3 (depends on 1)

The aluminum alloy brazing sheet according to claim 1, wherein the filler metal further includes one or more elements from among 0.004 to 0.2 mass % of Bi, 0.05 to 0.4 mass % of Mg, 0.002 to 0.05 mass % of Sr, 0.003 to 0.07 mass % of Sb, 0.05 to 0.8 mass % of Fe, 0.05 to 0.2 mass % of Mn, and 0.01 to 0.15 mass % of Ti.

### Claim 4 (depends on 2)

The aluminum alloy brazing sheet according to claim 2, wherein the filler metal further includes one or more elements from among 0.004 to 0.2 mass % of Bi, 0.05 to 0.4 mass % of Mg, 0.002 to 0.05 mass % of Sr, 0.003 to 0.07 mass % of Sb, 0.05 to 0.8 mass % of Fe, 0.05 to 0.2 mass % of Mn, and 0.01 to 0.15 mass % of Ti.