Main characteristics of aluminum alloy welding

1. Aluminum is easily oxidized in air and during welding, and the generated oxide layer has a high melting point, is very stable, and is not easy to transfer, which hinders the melting and fusion of the base material, and the oxide layer has a large proportion, which is not easy to float out of the surface, and is prone to defects such as inclusion, incomplete fusion and incomplete penetration.

2. The thermal conductivity and specific heat capacity of aluminum are relatively high. In the welding process, heat is easily consumed. In order to produce high-quality welded joints, try to use concentrated and high-power energy, or use preheating technology.

3. The linear expansion coefficient of aluminum is high, the volume shrinkage rate during solidification is large, and the deformation and prestress of weldment are large, so corresponding measures should be taken to prevent it during welding.

4. Aluminum has a strong reflection ability to light and heat, and there is no obvious color change during solid-liquid conversion, so welding is difficult to judge and easy to weld through.

5. Aluminum alloy elements are easy to evaporate during welding, which reduces the performance of weld.