At present, the aluminum alloy used for welding is mainly composed of aluminum manganese alloy and aluminum magnesium alloy. Aluminum-copper alloys and aluminum-lithium alloys with higher specific strength and specific stiffness are also used in important fields such as aerospace. These aluminum alloys mainly have the following welding characteristics. First, the aluminum alloy has a particularly strong oxidizing ability, and an oxide film is formed during the soldering process. Second, the aluminum alloy has high electrical conductivity and thermal conductivity, and does not generate internal stress due to local overheating, but therefore requires more energy. Third, the linear expansion coefficient and the solidification volume shrinkage ratio are relatively large, and it is easy to form hot cracks. Fourth, there is no specific color change in the aluminum alloy during welding, which makes it difficult for the welder to observe. Fifth, the aluminum alloy is easy to inhale gas at high temperatures, and pores are formed during the welding process.
Analysis and Research on Common Defects of Aluminum Alloy Welding
Because of the welding characteristics of the aluminum alloy itself, and various other reasons, cracks, pores, poor weld bead formation, and undercuts are prone to occur in the welding of aluminum alloys. The following article will analyze the causes of each defect and propose specific countermeasures.