Anodizing on aluminum die casting parts

Anodizing on aluminum die casting part

Anodizing is an electrolytic passivation process on the metal surface treatment or finish. Anodizing on aluminum parts(Extrusion aluminum partsand aluminum die casting parts)  will increase the resistance to corrosion and provides better adhesion. The part itself with anodizing will be harder than before. Also it can have better insulation ability and heat insulation ability.

At the early stage of designing process, the designer may add the anodizing surface finish on the aluminum part. We understand the early prototype may be produced by CNC machining by pure aluminum ( like AL 6063-T5 or AL 6061-T6), so we have no problems with that. However, when it comes to the mass production stage, when we consider to make the aluminum partS by aluminum die casting process.  Then we see the anodizing is not a good option.

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Why can we get black color only on aluminum die casting part after anodizing?

Casting aluminum material is a kind of alloy which includes Cu, Fe, Tb, Si, Mg, Zn, Mn .etc. Beside the aluminum. Due to the element of Si, when the anodizing happens on the cast aluminum part, the surface will turn gray and black. The color is like something after burning. If you touch the surface very hardly, there may have some little ash coming off.

Currently, you can only get black color on aluminum die casting part after anodizing.

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When can we use anodizing on the aluminum die casting part?

If your aluminum die casting parts need good appearance , anodizing is not recommended .

If your aluminum die casting parts is functional part inside which needs better performance on strength and hardness.  Black Anodizing is a very good choice.

If you ask for a Black finish with no coating thickness, black anodizing is possible to consider.

Please feel free to contact with us at sales@shunhogroup.com.hk for more technical assistance.