Method for removing oxidation film and brazing foamed aluminum through self-friction of foam walls

Abstract

The invention discloses a method for removing an oxidation film and brazing foamed aluminum through self-friction of foam walls, which relates to a welding method in the brazing field and solves the problem that the joint strength is reduced as brazing filler metal is non-wetting and the oxidation film is removed difficultly in the brazing process of the foamed aluminum. The method for removing the oxidation film and brazing the foamed aluminum comprises the following steps that: 1. two foamed aluminum plates are heated, and the rodlike brazing filler metal can slide on to-be-welded surfaces of the two foamed aluminum plates in a reciprocating way respectively, so that the brazing filler metal can be coated on the to-be-welded surfaces; 2. the end surfaces of the two foamed aluminum plates, which are coated with the brazing filler metal, are butted, and the brazing filler metal on the contact surfaces of the two foamed aluminum plates can be in a molten state after heating; 3. the foamed aluminum plates clamped by slidable fixtures can slide at the to-be-welded interfaces in a reciprocating way, and the pressure is exerted in the direction vertical to the welding surfaces at the same time; and 4. the sliding of the foamed aluminum plates can be stopped, the to-be-welded surfaces of the two foamed aluminum plates are aligned with each other and are pressurized again, heat preservation is carried out on the to-be-welded surfaces of the two foamed aluminum plates for 1-3 minutes, and then the to-be-welded surfaces of the two foamed aluminum plates can be cooled naturally to the room temperature, so as to realize a metallurgical-bonding brazing interface between the two foamed aluminum plates. The method for removing the oxidation film and brazing the foamed aluminum can be used for welding the foamed aluminum.

Description

technical field

[0001] The invention relates to a welding method in the field of brazing, in particular to a welding method for foam aluminum butt joint and lap joint. Background technique

[0002] Aluminum foam is a foam-like ultra-light metal material, and its unique pore structure makes it multifunctional and composite. Usually the porosity of aluminum foam is very high (>80%). Aluminum foam with a porosity of 90% has a density of only 0.27g / cm 3 , about 1 / 4 of the density of water. At the same time, foamed aluminum also has outstanding mechanical properties. When porous metal is subjected to compressive stress, the stress in the plastic deformation stage on its stress-strain curve is almost constant. When they deform, a large amount of energy is converted into plastic properties. Dissipates as heat and is an excellent material for impact protection. In addition, porous metal is also a typical ductile material, which can prevent instant catastrophic failure when th...

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