A Study on the Tribological Behavior of Valve Train System by Low Friction Coating
The contact in the valve train system is known to be the part subject to significant load in an automobile engine. For such reason, the wear of the contact accounts for the greatest portion of entire friction loss of an engine, leading to the occurrence of abnormal wear. In order to reduce the wear in the valve train, this study first formed a crn layer to increase the bonding force with the base metal using the pvd coating method and then applied a 2-layer coating that formed the wc/c layer with low friction/wear resistance characteristics. In addition, it examined the friction characteristics occurring between the cam and tappet by using the dedicated wear tester and found that the friction torque value was reduced significantly through comparison testing with the existing part when the crn+wc/c coating was applied.
Alan K.T. Lau, J. Lu, Vijay K. Varadan, F.K. Chang, J.P. Tu and P.M. Lam
J. H. Seo et al., "A Study on the Tribological Behavior of Valve Train System by Low Friction Coating", Advanced Materials Research, Vols. 47-50, pp. 1470-1473, 2008