Tribological Performance of Alternating-layered Si-DLC/DLC Films under Humid Conditions

The tribological behavior of alternating-layered diamond-like carbon (DLC) films was examined under a variety of humid conditions. Alternating deposited layers with Siincorporated DLC (Si-DLC) and DLC films were prepared using a hybrid coating system. The residual stress of the alternating-layered films was reduced while the hardness was relatively less dependent on the number of alternating-layered sets. A ball-on-disc type tribological test was carried out under the following humid conditions: dry, 50 and 90 % relative humidity. The friction coefficient for higher number of alternating-layered sets decreased with increasing humidity conditions but there was no dependency on the wear rate.