Dear velle,

Back in 1994 at the American Ceramic Socity Meeting there was a Japanese Manufacturer that manufacturers ceramic springs at the Vendor displays.  The name of the Company was NHK Spring Co., Ltd that made in 1994 silicon nitide springs(both coil springs and flat springs).  Their USA address is as follows.

NHK International Corp.
13961 Farmington Road
Livona, Michigan   48154
Phone:(313) 427-3300
FAX:(313) 427-5117

This address is back from 1994 but I hop it points you in the right direction.

Best Regards,

Genesis

Genesis

Two articles that you might find interesting are:
http://www.azom.com/details.asp?articleID=95
http://www.azom.com/details.asp?articleID=932
Both have information on ceramic springs

They're fine if you don't have high impact. If so, you machine springs out of graphite and C-C.