Sliding friction and wear behavior of C/C composite ring against C/C composite block

Three kinds of C/C composites with different matrix carbon were prepared, and then the ring-block sliding friction behavior was tested on M2000 tester against C/C ring with smooth lamination structure pyrocarbon matrix(SL).The results show that the coefficient of friction(COF) of the composite with SL(composite A) or resin carbon matrix(composite B) is lower than that of the composite with rough lamination structure pyrocarbon matrix(composite C). The COF of composite A and B decreases with the increase of load, while that of composite C increases at first and then decreases with the highest value of 0.145 at 100 N. The volume loss of composite A and B is close and remain stable when the load is higher than 80 N with the highest value is only 0.39 mm3. But the value loss of composite C increases up to the highest value of 1.47 mm3at 100 N and then remains some fluctuation. The COF of composite A can reach the stable value quickly while those of composite B and C still decrease after 5 hours' test. SEM images of worn surface show that some large film on composite A is peeled off, some dotted adhesive wear scar can be found on the worn surface of composite B. Abrasive worn is the main wear mechanism for tribological behavior of the three C/C composites.