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Behavioural characteristics of Titanium & Graphite

  1. Dec 18, 2014 #1
    Hi all,

    Does anybody have any experience with titanium and graphite in terms of friction and wear over time in a relatively high temperature environment?
    I realise that galvanic corrosion shouldn't be too much of an issue, but I was wondering from a sort of tribological point of view.
    Hope this makes sense
    Thanks in advance
  2. jcsd
  3. Dec 20, 2014 #2
    Graphite depends on having minuscule amounts of water in its environment to maintain its lubricity. In a very dry environment or one hot enough to drive off intercalated water, it becomes quite abrasive. This was first found, IIRC, in WWII when graphite brushes in electric motors flown at then-novel high altitudes ( = very dry air) started chewing into the commutator metal.

    Titanium against graphite at high temperatures is likely to wear fairly fast. I speculate the graphite will damage the native TiO2 layer, which will expose underlying Ti to further oxidation and to reaction with the graphite. Ti forms TiC fairly readily at elevated temperatures. There are copper-based high temperature lubricants that might work for you.

    The tribological performance of Ti/graphite depends on speeds, loads, etc. as well as temperature and atmosphere composition. If the environment is other than air, my comment is not likely to apply.
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