Research Of The Composite Depositing On Friction And Wear

The friction pair of cylinder and piston ring is the most important component in the engine, of which status has great influence on the performance of machine. After the friction between traditional cylinder of40Cr piston ring treated by PVD, their friction factor will increase and the wear become more serious.In this experiment,40Cr cylinder was processed by composite treatment of nitriding and vacuum cathodic arc deposition. Before and after the friction and wear test between cylinder and the piston ring, after combined treatment of pairing for friction and wear test, and the cross-section surface of cylinder was investigated by the optical microscope (OM). The results shows that no shedding phenomenon didn’t happen to the composite coatings of cylinder. Cylinder surface was investigated by surface roughness measuring instrument and confocal laser before and after the experiment, showing that the wear of the composite coating was small.In this experiment, the friction coefficient was calculated by the friction force between cylinder and piston ring during the wear process. After many tests, the friction coefficient of0.12and0.13of untreated piston ring friction is better than the composite plating. And the suitable conditions is nitriding at520℃for30min then Vacuum cathodic arc deposition with the furnace voltage is from50V to125V as well as the pressure of10-2Pa for the40min.