During anodizing, pitting is one of the more common faults in electrolytic polishing. The content of chromic acid in the electrolyte is too high, the temperature is too high, the current density is too high, the content of sulfuric acid is too low, the viscosity is too high or too low, chlorine Excessive ion content, excessive trivalent chromium content, unreasonable stirring and poor pretreatment before electrolytic polishing will all lead to pitting during anodic oxidation.

If pitting occurs during anodizing, what should we do?

If pitting occurs on the surface of the workpiece during the anodizing process, comprehensive analysis is required to distinguish the primary and secondary of the contradiction before solving it. Insufficient chromic acid content and slow groove speed will also cause pitting on the surface of the workpiece. When pitting (or pitting) occurs during aluminum oxidation processing, it can be solved according to the following steps:

First, first check whether the temperature is too high and the current density is too high. If so, the temperature should be lowered. If the temperature is not too high, the voltage can be appropriately lowered to continue production while the temperature is lowered. It is necessary to stop production and wait for the temperature to drop to the process range, or add some cold acid to the electrolyte to accelerate the temperature drop. Second, add an appropriate amount of sulfuric acid. Third, if the viscosity is too high, you can add an appropriate amount of sulfuric acid or a small amount of pure water. Fourth, if more water is mixed in to make the viscosity excessive, the relevant content in the white frost treatment method can be used. Fifth, if the concentration of chloride ions and macromolecular organic additives are too high, it can be dealt with by replacing part of the electrolyte. The above is how we deal with the pitting (or pitting) of the workpiece when we encounter aluminum anodizing.