Abstract
Demand for reduction in friction and improvement in wear resistance of moving parts propels exploration in frictional origin for amorphous carbon (a-C) film lubricating properties based on the interfacial states. Methane, as an ideal energy carrier and industrial raw material, is one of active gas. Consequently, the relations between the tribological behaviors of a-C film under methane atmosphere and load or interfacial states were discussed based on experimental and theoretical methods. Experimental results illustrated that, as the load increased, tribological system exhibited various interfacial shear strength at a load of zero and pressure dependence of the shear strength for tribological systems. And then the origin was revealed with theoretical calculation and resulted from the distributions of adsorbates across the sliding interface.