Tribological properties of aligned film of amorphous carbon nanorods on AAO membrane in different environments

The aligned film of amorphous carbon nanorods was synthesized by chemical vapor deposition at 650 °C with the Co catalyst on a porous anodic aluminum oxide (AAO) membrane. The morphology and microstructure of the aligned film of amorphous carbon nanorods were examined by field emission SEM, TEM and Raman spectroscopy. The tests sliding against a quenched-and-tempered GCr15 steel were conducted using a ball-on-disk tribometer at an applied load of 980 mN and a sliding velocity of 0.2 m s−1 in vacuum, humid air (RH 60%) and oxygen-rich environments. The tribological properties of the aligned film of amorphous carbon nanorods on the AAO membrane were influenced by the test environment. As compared to the tests in humid air and oxygen-rich environments, the aligned film of amorphous carbon nanorods showed slightly higher friction coefficient in vacuum, but exhibited higher wear resistance at the same time due to the absence of tribochemical reaction. The mass loss of the aligned film accelerated by the effects of oxygen and atmospheric humidity in humid air due to tribochemical reaction.