Hardcoat for 2024 Aluminum

[enirwin]

I am experiencing fretting wear between a plate made of O-6 tool steel and a housing made of 2024 aluminum, anodized per MIL-A-8625, Type 2, Class 1. The steel part was originally aluminum but was changed to resist some pretty severe cavitation. I am working to eliminate the motion that is driving the wear, but I would also like to improve the wear couple.

I'm considering changing the plate to Toughmet, a nickel/tin/copper alloy made by Brush Wellman which has good cavitation resistance. This should produce a better wear couple with the aluminum, but I would also like to increase the wear resistance of the 2024 housing. My understanding is that the effectiveness of anodize on 2024 is poor due to the high copper content, but I need the 2024 for it's strength properties at elevated temperatures. Can anyone recommend a coating that works well with 2024 to increase the wear resistance?

I've seen some promising information on Keronite and Microplasmic coatings and they claim to work well with 2XXX series aluminum. Any experience with these coatings?

Thanks.

 

[unclesyd]

Have you looked at using AlClad 2024 in you application. Though not directly involved we had a similar condition as you state which was resolved using this material. They were able to get a better hard anodize, at the time a GE process, on the clad that worked.

Though I haven't used any of the coatings that you mention I have used anodized Al to eliminate some of the same type problems. In several applications I have found that a dry film lubricant applied to the anodized surface greatly enhanced the frictional characteristics of the Al.