Guarantee on Fatigue Reliability of Multi-Layered DLC-Coating Given to CD-Carburized SCM415

In this research, surface modification was given to CD (Carbide Dispersion)-carburized steel used for sliding parts of vehicles, and functional evaluation was performed. It developed the DLC-coating which has multi-layered structure according to a UBMS (UnBalance-Magnetron-Sputtering) process as aims at improvement in the tribological properties in the sliding parts for vehicles. In order to maintain the adhesion with parent material (CD-carburized steel), intermediate layer that gradient hardness was generated. Structure of multi-layered part was made into ten layers. The multi-layered part consists of soft layers and hard layers. A soft layer bears high-ductility and the hard layer bears wear resistance and tribological property. Moreover, as functional evaluation of coating material, it investigated about the friction wear characteristic and influence that a DLC-coating has on the fatigue characteristic.