3003 aluminum weldability is easy to weld and can be used to make parts that require welding. 3003 aluminum sheet is used in processing that requires good formability, high corrosion resistance and good weldability, or requires both these properties and higher strength than 1XXX alloys, such as kitchen utensils, food and chemical industry, product processing and storage devices, tanks and tanks for transporting liquid products, various pressure vessels and pipes processed with thin plates.
Welding process tests were carried out on 3003 aluminum weldability, and the microstructure and mechanical properties of the welded joints were analyzed. The results showed that under the condition of surface focusing, when the welding speed was 40 mm/s, the laser power was 1350 W, and the pulse frequency was 5000 Hz , when the swing frequency is 100 Hz and the swing diameter is 0.3 mm, a well-formed welded joint can be obtained on 3003 aluminum sheet. There are fine-grained regions at the fusion line of the welded joint and the center of the weld, and the transition zone from the fusion line to the center of the weld is composed of columnar grains. The microstructure has been refined. The hardness of each zone of the welded joint is higher than that of the base metal, the tensile strength is about 91% of the base metal, the elongation after fracture is about 65% of the base metal, and the fracture mode of the joint is a mixture of toughness and quasi-cleavage fracture.
Aluminum is easily oxidized in the air and during welding, and the resulting alumina (Al2O3) has a high melting point, is very stable, and is not easy to remove. It hinders the melting and fusion of the base metal, and the specificity of the oxide film is large, it is not easy to float out of the surface, and it is easy to generate defects such as slag inclusion, incomplete fusion and incomplete penetration. The oxide film on the surface of aluminum and the adsorption of a large amount of water will easily cause pores in the weld. Strict surface cleaning should be carried out by chemical or mechanical methods before welding to remove the oxide film on the surface. Enhance protection during welding to prevent oxidation. For gas welding, use a flux that removes the oxide film. When welding 3003 aluminum plates, the welding heat can be increased. For example, the heat of the helium arc is high, and the shielding of helium or argon-helium mixed gas is used, or the large-scale melting electrode gas shielded welding is used. In the case of direct current connection, the “cathode clean up”.