Subject: Palladium Catalysis

From: "Hogue, Pat (AZ76)" <[email-masked]>
Date: Tue, 9 Dec 1997 10:18:50 -0700

Greetings CCL-ers:

     I need a recommendation on software to model, and any experience
people may have, for the following problem:

     An alloy of Pd, Pt, Au and Ag rolls against an alloy of Au, Pt, and
Ag in perfluoroisopropylether, also called perfluoropolyalkylether
[PFPAE], the fluid is not degassed so it probably contains lots of
dissolved oxygen.  Minor additions of Cu and Zn are present to cause
dispersion strengthening of these alloys.  The manufacturer's
metallurgist says Cu ands Zn are present as intermetallic (spinodal)
phases, so free Cu or free Zn are not available to diffuse throughout
the alloy and do nasty things like react with oxygen.

     As time goes by the rolling electrical contact resistance begins to
become somewhat erratic and steadily rises.  During over night quite
conditions the resistance continues to rise.  

     My first impression is that surface chemistry (probably palladium
catalyzed decomposition of PFPAE) may result in the formation of an
insulating "friction polymer" e.g., Teflon or some other polymer
containing  oxygen, fluorine, and carbon.  Of course oxidation of
surface elements is probably also part of the cause for increased
resistance.

    Are there programs that look at surface catalysis?  Any suggestions
for software or experience will be appreciated.