http://www.ceracarbon.com/ceracarbon/ and ceramic coated Al sprockets http://www.ceracarbon.com/ceradure/ I noticed this in an article on Ducati's Jounce(?) box http://www.motorsportmagazine.com/opinion/motogp/anti-chatter-jounce-box
I've seen a torsional load test on a Mercedes or BMW tailshaft between carbon fibre and the aluminium alloy alternative - needless to say carbon won this is an interesting use of carbon to sat the least