Preparation method of foamed-aluminum sandwiched-structure materials

Abstract

The invention relates to a preparation method of foamed-aluminum sandwiched-structure materials and belongs to the technical field of aluminum brazing. The preparation method includes steps of mixing blazing filler metal with brazing flux into paste to apply on surfaces to be brazed of foamed aluminum and aluminum plates, assembling a to-be-brazed structure according to a mode of the aluminum plate / foamed aluminum / the aluminum plate, brazing in a furnace at the protective atmosphere to obtain the foamed-aluminum sandwiched-structure materials after totally drying. The brazing filler metal comprises, by mass percentage, 11-13% of Zn, 14-16% of Si, 0.8-1.2% of Fe, 0.1-0.3% of Mg, 0.2-0.4% of Mn and the balance of Al. The brazing flux comprises, by mass percentage, 40-50% of KF and 50-60% of AlF3. By adopting the novel brazing filler metal and the brazing flux and strictly controlling brazing temperature and time, the prepared foamed-aluminum sandwiched-structure materials have excellent performance. Complicated procedures in brazing are greatly reduced, operation efficiency is greatly improved, and cost is saved.

Description

technical field [0001] The invention relates to a method for preparing a foamed aluminum sandwich structure material, belonging to the technical field of aluminum material welding. Background technique [0002] The aluminum foam sandwich structure material is a sandwich structure material composed of a metal panel and an aluminum foam sandwich layer. This type of material has various excellent functions such as light weight, sound absorption, and impact resistance, so it can be widely used in chemical industry, metallurgy, aerospace, Electronics, marine, automotive and construction industries. With the deepening of development, its scope of application is still expanding. [0003] In the prior art, there are mainly three methods for preparing foamed aluminum sandwich structure materials. One is the adhesive bonding method, which mainly depends on the properties of the binder. It will have a great impact on the mechanical properties of the material, which will greatly limit...

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Problems solved by technology

[0003] In the prior art, there are mainly three methods for preparing foamed aluminum sandwich structure materials. One is the adhesive bonding method, which mainly depends on the properties of the binder. It will have a great impact on the mechanical properties of the material, which will greatly limit the application; [Belingardi G, Cavatorta MP, Duella R. Material characterization of a composite–foam sandwich for the front structure of a high speed train .Compos Struct 2003; 61:13-25.]; The second is the rolling composite-powder metallurgy method, which has defects due to the impact of density; [Zhang Min, Guo Yin, Yao Guangchun, etc. Foamed aluminum Preparation of sandwich panels and research on their interfacial bonding mechanism [J]. Functional Materials, 2006, 37(2): 281-283.]; the third is to prepare foamed aluminum sandwich structure materials by welding, and the existing welding is used to prepare foamed aluminum sandwiches In structural material technology, during welding pretreatment, it is generally just simple mechanical scraping, or only soaking in lye, which can remove oxides and impurities to a certain extent, but the effect must be insufficient, and the aluminum foam and Impurities and oxides on the surface of the panel cause the welding to be weak in the following welding process; during welding, due to the incomplete removal of oxides in the pretreatment process, the welding is not tight, and at the same time, it may also be caused by welding during the welding process. The control of temperature and welding time has not reached an optimal combination, resulting in over-burning, resulting in shrinkage of foamed aluminum and panels due to melting;