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Coating aluminum for corrosion resistance and wear resistance?

I have an aluminum casting on a steel rod. the steel rod rotates inside a brass bushing. My problem is the aluminum wears off as it rides against the brass bushing. I'd like to make a washer to ride between the aluminum and brass to act as a wear plate. I had planned to bond it to the aluminum. it will be in a moist environment. what material can I use that will have high wear resistance , not react with either aluminum or brass and not be affected by a moist environment.

Murri Decker
product test engineer - West Henrietta, New York, USA
May 20, 2010

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First of two simultaneous responses --

I would work with an anodizer that does type III hard anodize.
Multiple metals in a moist environment is never a good idea.
You could look at electroless nickel on the aluminum.
You might be able to get away with making a 316 SS bushing and shrink fit it into the aluminum by heating the aluminum and freezing the bushing in liquid nitrogen or a dry ice alcohol mixture. You need to be fairly quick with the insertion, but I have seen bushing that you could not drive out with a press.

James Watts
- Navarre, Florida
May 21, 2010

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Second of two simultaneous responses --

Maybe you can use a mechanically attached steel insert or heavy bushing (splines or lock pins).

Guillermo Marrufo
Monterrey, NL, Mexico
May 22, 2010

As an electroless nickel plating company we have many clients who want their aluminum components plated for wear reasons. Sometimes they ask us to apply a nickel teflon coating for a smoother surface to prevent wearing of the layer as teflon works as some kind of lubrication.

Harald Machiels
- Genk, Limburg, Belgium
January 12, 2011