Friction Surface and Wear Debris of Carbon-carbon Composites under Simulating Normal Braking Condition

Friction and wear properties of carbon/carbon(C/C) composites with a rough laminar matrix carbon under simulating normal braking condition were tested by using the MM-1000 tester.The morphology and graphitization of carbon at friction surface were investigated by SEM and micro-Raman spectroscopy respectively.The friction and original surfaces were characterized by using FT-IR and Tg respectively.The results show that the friction coefficient,linear and mass wear rate during simulating braking were 0.32,0.48 μm,and 2.12 mg respectively.Friction film was observed when the len was vertical to friction surface,while rugged surface was seen when the len was parallel to friction surface.The degree of graphitization of carbon crystallites in friction surface was different from those in original surface.R value at grey area in friction surface was as high as 1.03,which was about five times of that in the original surface(0.207),while that in the local white area was only 0.084.This may be attributed to the effect of nanometer wear debris and concentration of stress.Compared with original surface,the mass loss of carbon in friction surface was higher than that in the original surface due to decomposition of SOCs at friction surface.