Hard anodizing plating line:
Hard anodized aluminum main purpose is to improve variety performance of aluminum and aluminum alloys, including corrosion resistance, abrasion resistance, weather resistance, insulation and absorption and so on. It applies to the deformation of aluminum alloy, and it may also be used for pressure casting aluminum parts. Mostily we know it is perfect of aluminum pot manufacturer.
Hard anodizing full name and hard anodization treatment.
Hard anodizing plating line technical method:
Hard anodizing electrolytic has many ways, such as: sulfuric acid, oxalic acid, propylene glycol, sulfosalicylic acid and other inorganic salts and organic acids. Thepower supply can be divided into DC rectifier, AC power supply, AC-DC superimposed anodizing rectifier, superimposed pulse and pulse power supply and so few, the widely used as below:
(1) Sulfuric acid hard anodic oxidation.
(2) Oxalic acid hard anodic oxidation.
(3) Mixed acid type hard anodization.
Among them, sulfuric acid is to be more widely applied for hard anodizing plating line.
Hard anodizing plating line working principle:
Pure sulfuric acid type hard anodizing general principles compare with normal oxidation is no essential difference, if it is a mixed acid type will have attachedreaction. The reaction is essentially:
1. Cathode reaction:
4H + + 4e = 2H2 ↑
2. Anode reaction:
4OH – － 4e = 2H2O + O2 ↑
3. Aluminum oxidation: the anode precipitated oxygen at the atomic state, more active than molecular state, more likely to react with the aluminum:
2A1 + 3O → A12O3
Hard anodizing plating line characteristic:
Electrolysis act at a temperature of -10 ℃ ~ + 5 ℃ electrolyte. Because hard anodizing the resulting oxide film having a higher resistance to oxidation will directly affect the strength of the current. In order to obtain a thick oxide film, need to increase the external voltage, its purpose is to eliminate the large resistance impact, making the current density to keep constant, but when current large will produce intense heat phenomenon, together with large heating when producing anodizing film will release a lot of heat, so that workpiece temperature increasing temperatures will accelerate the dissolution of the oxide film, the oxide film can not be thickened.
Solution: use our special design hard anodizing plating line and rectifier.