Why Does Aluminum Need Anodized?
Aluminum itself is a strong corrosion-resistant substance. The surface of aluminum will form aluminium oxidation after meet the oxygen that will slowly remove his resistance for a long time past. In addition, it is very sensitive for acidic substance, acid will destroy aluminum surface formation layer, then we need to made anodized surface treatment again and add a layer of protective film on the surface in order to strengthen the corrosion resistance of the surface, aluminum pipe or aluminum products which its corrosion resistance, hardness, wear resistance, insulation, heat resistance, etc. have been greatly improved after anodized surface treatment. The anodized treatment of aluminum tubes is generally carried out in acidic electrolyte, with aluminum as anode. In the electrolysis process, the anion of oxygen and aluminum effect to produce anodized film. The initial formation of this film is not fine, although there is a certain resistance, but the negative oxygen ions in the electrolyte still can reach the aluminum surface to continue to form an oxide film. As the thickness of the film increases, the resistance becomes larger and the electrolytic current becomes smaller. At this time, the outer layer of the anodized film takes chemical dissolution with the electrolyte. When the velocity of the oxide on the surface of the aluminum is gradually balanced with the rate of chemical dissolution, the anodized film can reach the maximum thickness under this electrolytic parameter. The anodized film of aluminum is porous, it is easy to adsorb dye and colored material, so it can be dyed and its adornment is improved. The oxidation film can further improve its corrosion resistance and wear resistance after the sealing treatment of hot water, high temperature steam or nickel salt.