Why is die -cast aluminum not suitable for anodizing?

I believe that many manufacturers should find that when die-casting aluminum, the die-cast aluminum is not suitable for anodizing. This is all determined by the composition of anodized aluminum and the characteristics of anodizing. So why is n’t anodized aluminum suitable for anodizing?

First of all, anodizing requires no impurities on the aluminum surface, and the aluminum material is relatively pure, because the anodized film must be uniform and flat. The presence of excessive impurities and other components will inevitably affect the thickness of the film formed during anodization, and even directly affect whether or not a film is formed. The most important thing is that other metal elements may directly change the color of the film when the anodized film is formed, which directly pronounces the death penalty on the dyeing after the anodizing.     Cast aluminum alloys and die-casting parts generally have a higher silicon content. Even if ht412 die-casting aluminum special ash remover is used, the anodized film may be dark, and it is difficult to obtain a colorless and transparent oxide film. Increase, the color of the anodized film changes from light gray to dark gray to black gray. Therefore, cast aluminum alloys are not suitable for traditional anodizing.