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; the second is to use the rolling composite-powder metallurgy method, which has defects due to the impact of density; the third is Welding is used to prepare foamed aluminum sandwich structure materials. In the existing welding preparation technology of foamed aluminum sandwich structure materials, welding pretreatment is generally just simple mechanical scraping, or only lye soaking is used, which can remove oxidation to a certain extent. impurities and impurities, but the effect must be insufficient, and the impurities and oxides on the surface of the foamed aluminum and the panel are not completely removed, resulting in weak welding in the next welding process; during welding, due to the oxides not being removed during the pretreatment process It is easy to cause loose welding, and at the same time, it is possible that the combination of welding temperature and welding time has not reached an optimal combination during the welding process, resulting in overheating, resulting in shrinkage of foamed aluminum and panels due to melting; resulting in loose welding Another reason is: the selected flux and solder are inappropriate; the following are the commonly used brazing materials in the prior art and the matching brazing fluxes (by mass fraction), all of which have the above-mentioned problems: