Effects of Microstructure on the Frictional Properties of C/C Composites

Microstructure of C/C composites with resin-derived carbon and rough laminate pyrocarbon was studied by transmission electron microscopy(TEM),scanning electron microscopy(SEM).And effect of microstructure on frictional properties was discussed.TEM and SAED results showed that the resin-derived carbon near the carbon fibers was highly graphitized,which conferred appropriate and stable friction coefficient on composites.Because of the visible cracks between resin-derived carbon lamellae and the isotropical carbon beyond the carbon fiber,resin-derived carbon was readily destroyed by shearing.This gave a birth of a large number of chippings and disturbed the dynamic equilibrium.The high wear rate of the composites was the main problem for the application as a braking disc.