Galling with various metal on metal combinations

I have an application where a flat, .75 diameter surface made of 303S stainless bar is being slid along 7075-T6 AL  surface with approximately 3.6 pounds of force. The problem is that the 7075-T6 is galling. Can anyone recommend two metals that would work well together in this situation without lubrication? Or possibly a metal/poly combination.
Or even a web site or book that I might reference to find metal on metal recomendations.  

Try Nitronic Alloy or varing hardness of the two metals should decreases gaulling

Why don't you start by hard anodizing and also consider teflon impregnating the surface. A great company to deal with is General MagnaPlate, they can offer numerous coating options to solve your problem.

www.magnaplate.com

Best Regards

As 3.6 pounds load on 75 mm diameter surface is small.  It is still in the low wear rate regime where fine black powder debris are produced.  these black powder is nothing more than fine particles of Al and steel and not much oxide.(see wear mecahnism maps for aluminium/steel).  I could not understand how you get galling (gross material transfer, I suppose) at these low loads.  It can happen if the intial apparent contact area is small and thus high contact stress.  Check contact geometry whether the whole surface is in contact when you strat moving.  

Alternatively, you could try Al-12 wt.%Si alloy instead of 7075-T6, if cast material is okay.

If you harden the steel or a hardened steel surface is used, generally Al alloy wear decreases (my Ph D thesis).  

If you can try another combinations, try steel on steel with approriate hardness levels (i.e composition and heat treatment).  Refer to any good book on wear or wear control handbook.

There are numerous possible combinations possible - metal/metal, metal/polymer, polymer/polymer, etc., apart from ceramic and composite materials, if you design allows.  People who read these postings can give some guidance depending the info you supply.

Let me know if you need more info.

More information is needed; is the application wet or dry?
Can you tolerate any particles from wear?
Must the surfaces be clean; can you put on a coating?
Is lubrication allowed?
What is the temperature range?
What is the speed range?
What is your budget?

-The load is low enough to use PTFE (Teflon) or a similar polymer.  
-UHMW-PE is more afforable and has the same coefficient of friction as PTFE when wet, slightly higher when dry.  
-Drill and tap the end of the stainless part, and install a nylon-tipped setscrew facing the aluminum.
-Dow Corning makes a MoS2 solid lubricant spray that could be applied to one of the surfaces.  Least expensive approach (~$15) if it would work for you.
-Electroless Nickel plating on the aluminum could be hardened to ~Rc60.
-Hard anodizing the 7075 aluminum is difficult and would wear the 303SS.

We have a coating called Wearcoat, that will prevent galling and wear. If interested, you can contact me for further details in<coatings@asm-usa.com> or visit our website <www.asm-usa.com>;. Reliable coating is a better option than trying different material combination.

Dr.R.Sivakumar