Large industrial ceiling fans are composed of various components, and the main body structure is mostly welded with aluminum alloy materials. To ensure the quality of the welding process, it is necessary to prepare the aluminum alloy before welding, especially by removing oil and oxide from the surface.
Regarding oil removal: Since aluminum has a high solubility in the molten state, it is recommended to remove the oil from the welding area to reduce or eliminate the possibility of porosity. Various methods can be used to remove oil, for example, using a clean cloth without degreasing solvent. This method is very effective.
A mild alkaline solution is also an effective cleaning agent. The fan components that need to be cleaned can be sprayed with a solution or soaked in a container containing a solution. Because such cleaning agents are usually water-based, it is important to thoroughly rinse and dry after cleaning.
Many suppliers sell acidic cleaning solutions to clean aluminum parts. These cleaning solutions are usually effective and can remove excess oxide. However, these are acidic and some may contain ammonium fluoride, so be careful when using and handling them. The workpiece should be thoroughly rinsed and dried again.
Regarding oxide removal: Removing the oxide layer before welding large industrial ceiling fan aluminum alloy components is important for two different reasons. The melting temperature of aluminum oxide is higher than that of aluminum. If the oxide layer is too thick during welding, it may cause oxide defects in the weld. Oxides have permeability and may introduce water vapor in humid environments. If the welding material is not prepared properly, it may cause porosity in the welded parts.
Several methods can be used to remove oxide. The most commonly used method is to use a stainless steel wire brush. The wire brush should be clean and not previously used for cleaning other than aluminum parts. The wire brush should also be relatively flexible, and light pressure should be applied when using it to avoid unnecessary surface roughness of aluminum workpieces. Oxide can also be removed by immersing the parts in a strong alkaline solution, but these solutions are corrosive and may corrode the surface of aluminum alloy parts, so be especially careful when using them in some industries.
Therefore, before welding the aluminum alloy components of large industrial ceiling fans, it is necessary to first remove surface oil and then remove oxide. Only in this way can the welding work be ensured without unnecessary quality defects.