How to control the time of hard anodizing?

Do you know how to control the hard oxidation time?

Anodizing time is too long. It is easy to cause loosening and falling off. The film layer is rough. Anodizing time is too short. .The film is thin and smooth. It can be seen that too long or too short anodizing time is not good for quality. The time required for hard anodizing should be strictly controlled during operation.

(1) Pre-anodization time. When the workpiece enters the hard anodizing tank, a current of 0.5A/dm2 is applied immediately, and the current density is increased from 0.5A/dm2 to 2.5A/dm2 in 5 to 8 times within the next 25 minutes. This period of time cannot be short, otherwise it is easy to cause short circuit of the workpiece in the later film forming stage and cause ablation, and it is meaningless if the time is too long. ;

(2) Anodic oxidation film forming time. After the workpiece is pretreated for 25 minutes, when the current density is constant at 2.5-3A/dm2, the growth of the film layer officially begins at this time. Too long or too short this period of time is not good for quality.