Can aluminum alloy be welded?

There are two common welding methods for aluminum alloy, one is argon arc welding and the other is MIG welding. Ac power supply for argon arc welding of aluminum alloy and DC power supply for carbon steel. MIG welding is to weld aluminum alloy with argon gas protection, and the requirements for butt welding machine are also high. However, MIG welding, carbon dioxide protection or other mixed gas protection for carbon steel have low requirements for butt welding machines.

Compared with other metals, aluminum alloys are difficult to weld for the following reasons:

1, the melting point of aluminum and aluminum alloy is only over 600 degrees, which is easy to burn out and overheat during welding.

2. Generally, aluminum alloy is not resistant to high temperature, and its expansion coefficient is large, which is prone to welding deformation and obvious welding crack tendency. Thin aluminum alloy plates are more difficult to weld and easy to weld through.

3. Aluminum alloy welding is prone to porosity, because hydrogen in the molten pool cannot be discharged before the weld is formed, which leads to porosity in the weld.

4. When the surface of aluminum alloy is directly exposed to air, it is particularly easy to produce a refractory oxide film (composed of aluminum trioxide) on the surface, and the melting point of this oxide film is as high as 2050 degrees, so the oxide film cannot penetrate and cannot be welded during TIG welding. Before welding, aluminum should be cleaned and the surface oxide scale should be removed.