Aluminum alloy brazing plate

Abstract

An aluminum alloy brazing sheet characterized by comprising a core material, a brazing material composed of an Al-Si alloy provided on one surface of the core material, and a brazing material provided on the other surface of the core material. Brazing sheets made of aluminum alloy with a sacrificial material and a plate thickness of less than 200 μm, the core material contains Cu: more than 1.5% by mass and less than 2.5% by mass, Mn: 0.5 to 2.0% by mass, and the balance consists of Al and unavoidable impurities Composition, the sacrificial material contains Zn: 2.0 to 10.0% by mass, Mg: limited to 0.10% by mass or less, the balance is composed of Al and unavoidable impurities, the thickness of the brazing material and the sacrificial material are 15 to 50 μm, respectively, The total coverage ratio is 50% or less.

Description

technical field [0001] The present invention relates to an aluminum alloy brazing sheet suitable for use in heat exchangers for automobiles and the like. Background technique [0002] Conventionally, as a raw material for heat exchangers such as automobiles, a brazing sheet composed of an aluminum alloy (hereinafter, sometimes described as an Al alloy) with a brazing material and a sacrificial material on both sides of a core material has been used. . [0003] In recent years, heat exchangers for automobiles tend to be more lightweight and downsized, and accordingly, it is desired to reduce the thickness of brazing sheets constituting tubes that account for most of the mass of the heat exchanger. Up to now, the thickness of the brazing sheet can be reduced to about 200 μm, but in order to further reduce the thickness, it is necessary to achieve high strength and high corrosion resistance equivalent to the thinning. However, if the core material is made thinner along with t...

AI Technical Summary

Problems solved by technology

[0009] However, in Patent Document 1 and Patent Document 2, the thickness of the brazing sheet disclosed in the examples is at least 250 μm. In order to obtain a thin-walled brazing sheet with a thickness of less than 200 μm, it is necessary to achieve strength after brazing, durability There is still room for further improvement due to the combination of corrosion and brazing properties

[0010] It is clear that if it is a thin-walled material with a thickness of less than 200 μm, the thickness of the core part that bears the strength becomes thinner, so the residual amount of various additive elements after brazing heating is greatly reduced, and the strength will obviously be greatly reduced.

In particular, the reduction of the residual amount of Cu added to positively shift the potential of the core material has a large influence, and it is also confirmed that the corrosion resistance is lowered in addition to the strength.

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