Abstract
In this study, in order to investigate the effect of the Cr diffusion layer and the Diamond Like Carbon (DLC) film on fatigue properties of the carbon steel S45C.Firstly, Cr diffusion layer was formed on S45C. Secondly, DLC film was covered with S45C. However, the materials were heated to a high temperature during forming Cr diffusion layer. Therefore, the material only performed by heat treatment was prepared as compared materials. The fatigue test results showed that the fatigue strength of DLC materials with Cr diffusion layer was higher than that of heat treated materials. In order to examine the reason for that result, the fatigue crack propagation was observed by means of plastic replicas. According to this measurement, it was found that fatigue crack initiation life of DLC materials was longer than that of heat treated materials. Therefore, it was cleared that DLC film increased the fatigue crack resistance of S45C.
