The role of cermet interlayer on tribological behaviors of DLC/Cr3C2-NiCr duplex coating from the perspective of carbonaceous transfer film formation

The effect of applied load on the tribological behaviors of single DLC coating and DLC/Cr3C2-NiCr duplex coating was explored in the paper experimentally, and the role of cermet interlayer on the duplex coating tribological behavior was analyzed from the perspective of carbonaceous transfer film formation. Results proved that the duplex coating wear rate under 20 N was the lowest, about 1/6 of that of the single coating. The ex-istence of Cr3C2-NiCr interlayer can prevent the top DLC film from being damaged in high load friction, reduce the fluctuation and vibration of the friction interface, and help the friction-induced graphitized carbonaceous transfer film to maintain on the friction counterpart, thus realizing the low-friction of the duplex coating. Furthermore, the critical conditions under which the friction-induced carbonaceous transfer film of a single coating maintains on the friction counterpart are explored by designed experiments. Results show that the carbonaceous transfer film derived from the single coating can only maintain on the friction counterpart under conditions of low load, low sliding frequency, and high humidity, which indirectly confirms the excellent tribological performance of the duplex coating.