Correlation between the Tribological Behavior of Carbon Fiber Reinforced Copper Matrix Composite and Its Worn Surface Feature

An MM-200 test rig was performed to evaluate the friction and wear behavior of carbon fiber reinforced copper matrix composite sliding against AISI-1045 steel in a block-on-ring configuration. The morphologies and elemental compositions of the worn composite surfaces at different testing conditions were analyzed by means of scanning electron microscopy and energy dispersive spectrometry, while the worn surface roughness of the composite was determined on a profilometer. It was found that the carbon fiber reinforced Cu-based composite showed good friction-reducing and antiwear behavior in dry sliding against the steel ring, which was attributed to the self-lubricating ability and load-supporting effect of the reinforcing agent. The friction and wear behavior of the Cu-based composite was dependent on the friction and wear test conditions and the worn surface morphologies as well. It had a smaller wear rate at a relatively small sliding velocity, which corresponded to the polishing of the worn composite surface and mild plastic deformation; while a largely increased wear rate was recorded at an increased normal load, which corresponded to a rougher worn composite surface, owing to the enhanced plastic deformation and wear debris aggregation therewith. Since the carbon fiber reinforced Cu-based composite was liable to severe plastic deformation as it slid against the steel at a larger normal load or sliding velocity, it was suggested to use the composite as a kind of self-lubricating material at a normal load below 40 N.