First, when the oxide film layer is powdery or dusty, we should try to wipe it off first. It is necessary to sweep away the plugging ash and electric shock caused by the closing process.
Secondly, we will analyze the origin of oxidized fly ash one by one.
Generally, the dusting of the film layer is caused by the following points:
- 1. The temperature of the oxidation tank is too high;
- 2. The concentration of sulfuric acid is too low;
- 3. The aluminum ion content exceeds 18g/L. (The reason for the rapid increase in the aluminum ion content is mostly caused by the high temperature of the oxidation tank, and then the loss of the oxidation tank and the failure to salvage in time)
The temperature of the oxidation tank is too high, and it is necessary to determine that the cooling engine is not large enough? If the normal cooling capacity is okay, then consider the size of the cold water circulation, whether the temperature caused by the blockage of the circulating water pump is too high, and remove them one by one.
The sulfuric acid content should be checked regularly and compensated for the consumption of sulfuric acid brought in from the oxidation tank every day. Keep the time within the process range (180-220g/L is the best).
The temperature of the electrolyte has a great influence on the wear resistance of the oxide film. Generally speaking, if the temperature drops, the wear resistance of the anodic oxide film of aluminum and aluminum alloys will increase. This is caused by the decrease in the dissolution rate of the electrolyte for the film. , In order to obtain a higher hardness oxide film. We have to master the temperature within ±2℃ for hard anodizing treatment as well.