(1) uneven color
Definition: The color difference between the local and the finished product is different, and the appearance of electrolytic coloring is not uniform.
Cause: insufficient water washing after anodizing or long-time washing;
Abnormal water washing;
Short coloring time;
Insufficient agitation or excessive agitation.
Optimize the washing time after anodizing;
Washing water quality should be adjusted;
Extend the time of inflation;
Adjusting the concentration and pH of the coloring solution to remove impurities;
Improve cycle agitation conditions;
Adjust the pH value after washing.
(2) overlapping fading
Definition: Poor coloring that occurs when the material is electrolytically colored in a state of being passed through.
Phenomenon: The profiles are too narrow.
The fixture does not guarantee verticality when it is turned up.
Anti-shake devices shall be provided with reasonable materials and materials with large shaking;
Regularly maintain the fixture.
(3) Needle-like marks
Definition: The oxide film is cracked and its peripheral coloration is poor.
Phenomenon: Uncolored Iridium-like flow marks on the surface of the material, and the occurrence of the water chestnut portion of the material is high.
Cause: When the coloring treatment is performed by the pulse method, cracks are generated in the anodized film during the anode treatment, and gas is generated from the crack to hinder coloring.
Countermeasure: Optimize the electrolytic coloring conditions, especially the anode treatment conditions during pulse electrolysis.
Source: www.bombgroup17.com Keywords: aluminum oxide oxidation defects aluminum oxidation technology