To-fro sliding tribological behavior of C/C composite under different loads

Two C/C composites with different carbon matrixes were prepared. The long-term to-fro friction and wear behavior of theirs were tested against GCr steel mates in UMT-3 wear tester under different applied loads. The results show that the average coefficients of friction (COF) of composite A with rough lamination pyrocarbon matrix (RL) are larger than those of composites B with smooth lamination pyrocarbon/resin carbon matrix (SL/RC). The largest average COF of composites A is 0.193 produced under 60 N, while the least COF of composites B is 0.120 produced under 60 N. The gap on the average COF among the two composites increases at first and then decreases with the increase of the loads. With the prolonging time, all the COFs become stable. The worn surface of composites A forms by smooth and integrated friction film in spite of some big cracks, large block peeled film and alternately piled up film. For composites B, the rough friction film is composed of thick matrix carbon debris film and thin carbon fibers film.