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Hardwearing coating of Aluminium

1998

At the Philips Centre fo Manufacturing Technology Centre I work in a group specialised in tribological issues. Most of my time I am concerned with air bearings.

Because of reduction of weight a lot of my customers want to use Aluminium. To protect the aluminium surfaces we usely apply a hard anodisation process. My question is: Are there any other processes/coatings that give me a hard hardwearing surface.

The most critical condition for the coating process is that the dimensions of the parts have to be toleranced within a few micron. The second condition is that sharp edges have to remain sharp.

If anyone has a suggestion do not hesitate to reply.

Justus Post
Philips Centre for Manufacturing Technology - Netherlands

Chrome plating is one option, but it very probably would require post plate machining to maintain the dimentions.

Electroless nickel is a more viable option. Consider a low P one for no bake or low temp bake after plate. It will require a good shop, since it will probably be a one try per part operation and amount of deposit very tightly controlled.

Hard coat is probably your best option. Metalast impregnates with silver. It might enhance your hardcoat.

James Watts
- Navarre, Florida
1998

Then there is the CVD diamond-like-carbon (DLC) which is typically under a micron thick. It is suitable for low load applications on aluminum per our experience.

Mandar Sunthankar
- Fort Collins, Colorado
1998