Multi-layer material brazing aluminum material with excellent internal and external corrosion performance and preparation method of multi-layer material brazing aluminum material

Abstract

The invention discloses a multi-layer material brazing aluminum material with excellent internal and external corrosion performance and a preparation method of the multi-layer material brazing aluminum material. The multi-layer material brazing aluminum material is formed by sequentially stacking brazing layer alloy, first intermediate layer alloy, core layer alloy, second intermediate layer alloyand brazing layer alloy and then carrying out hot rolling compounding; the first intermediate layer alloy consists of the following elements of, in percentage by mass, less than or equal to 0.6% of Si, less than or equal to 0.7% of Fe, less than or equal to 0.2% of Cu, less than or equal to 1.5% of Mn, less than or equal to 0.1% of Mg, 0.8%-5% of Zn and the balance Al; and the second intermediatelayer alloy consists of the following elements of, in percentage by mass, less than or equal to 0.5% of Si, less than or equal to 0.3% of Fe, less than or equal to 0.2% of Cu, less than or equal to 0.1% of Mn, less than or equal to 0.45% of Mg, less than or equal to 0.1% of Zn, less than or equal to 0.1% of Ti and the balance Al. The multi-layer material brazing aluminum material has the beneficial effects that the first intermediate layer contains a certain amount of zinc and has very low corrosion potential, so that the core layer alloy is protected by sacrificing the first intermediate layer; and the second intermediate layer alloy with extremely low zinc content can play a very good role in protecting a low-PH 1.2-1.8 solution environment through an internal test due to the fact thatthe relatively pure components of the 1-series aluminum alloy are adopted, and therefore an excellent anti-corrosion effect is achieved on the cooled medium side.

Description

Technical field [0001] The invention relates to the field of multi-layer brazing aluminum materials, in particular to a multi-layer brazing aluminum material with excellent internal and external corrosion properties and a preparation method thereof. Background technique [0002] The composite materials usually used for aluminum brazing heat exchangers are mainly three-layer structures, such as tube sheets / tubes used as liquid-cooled intercooler structures, and double-sided symmetrical brazing layer structures. In recent years, due to the requirements of lightweight vehicles and improved heat exchange efficiency, some vehicle heat exchangers have been upgraded from the traditional air-cooled structure design to a liquid-cooled structure, and at the same time, they adopt intercooling with low-pressure EGR exhaust gas circulation. Due to the change of the cooling medium and the cooled medium, higher requirements are placed on the internal and external corrosion performance of the he...

AI Technical Summary

Problems solved by technology

In recent years, due to the requirements of lightweight vehicles and improved heat exchange efficiency, some vehicle heat exchangers have been upgraded from traditional air-cooled structures to liquid-cooled structures, and intercoolers with low-pressure EGR exhaust gas circulation gas access Due to the change of the cooling medium and the cooled medium, higher requirements are put forward for the internal and external corrosion performance of the heat exchanger material. At present, there are various multi-layer materials (four-layer or five-layer) with different combinations for this type of heat exchanger. Layer structure), but it cannot meet the anti-corrosion performance requirements of the cooling medium side and the inside and outside of the cooled medium side

[0003] The existing multi-layer materials are basically five-layer symmetric structure and four-layer asymmetric structure. By adding an intermediate layer with different composition between the core layer alloy and the brazing layer alloy, the material's resistance to cooling medium corrosion or Corrosion resistance of the cooling medium, or adding two symmetrical intermediate layers to improve the corrosion resistance of the material against the corrosion of the cooling medium or the corrosion resistance of the cooled medium, but it cannot meet the high requirements for both the cooling medium and the cooled medium side Occasions (for example, when the cooling medium is antifreeze, and the cooled medium is the intercooler gas introduced from the low-pressure exhaust gas circulation cooler), resulting in premature failure of the external or internal durability of the heat exchanger in this application

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