Materials used in clutches?

[TK96]

I am currently writing a case study on a clutch, specifically the clutch friction plate/disc, and the case study is about the materials used (in my case) the clutch friction disc. However, so far the information on the internet seems to a bit vague. I've only been researching for a few days so hopefully i will find some good information soon, but at the moment i am just trying to get info from as many sources as possible. I may even contact a manufacturer directly, as that is probably the best kind of primary research i could get.

The parts i intend to write about are:

The damper springs (or possibly the hub, i.e. the bit the springs sit in)
The friction material.

So far i have decided to base the case study on a ceramic clutch, since it is easier to write about than an "organic" clutch, and it is also more linked to my syllabus. (Although the ceramic friction materials arent just made of ceramic... it seems)

Does anyone have any information/knowledge on what the damper springs and friction materials are made of? Or know any places to look for decent information on clutches?

Thanks

[hollus]

http://scarbsf1.com/?p=3399

Probably Craig would be happy to help.