Quick determination technique of aluminum oxide film defect at aluminum anode

1, the appearance of aluminum oxide film frost: this kind of appearance is generally caused by the oxidation liquid temperature is too high, in more than 25 degrees, it is very easy to appear powder frost, so the most suitable temperature is 10-20 degrees. In addition, the current is too high will also cause powderization. 

2, aluminum oxide film rainbow color: the reason for this defect is that the oxidation time is too short, the oxidation liquid concentration is too low, the oxidation current is too small, and the hanging device contact is poor. Chloride ion is easy to corrode the film, and nitrate ion is easy to reduce the light sensitivity of the oxide film. Therefore, the content of impurity ions must be strictly controlled in production. Hard oxidation process workpiece in the curing process need to go through the same heating, heat preservation, cooling three stages, under the premise of baking curing temperature, the control of melting leveling time should be longer, melting level activity is better, conducive to the powder coating leveling, baking temperature is too fast, curing time is too short, the flow difference will lead to significant orange peel. However, the mechanism of powder coating leveling is more complex, there are many factors affecting the leveling of the coating, some factors are contradictory constraints, need to be considered comprehensively, on the basis of ensuring the mechanical function of the coating film, as far as possible to obtain excellent leveling function of the coating film.