Chromium nitride-coated copper beryllium as a cam tappet material candidate

Copper beryllium (CuBe) with good mechanical and high electrical conductivity properties is used in metalworking, electronic devices, automotive systems, and aerospace systems. Having low hardness limits its usage in tribosystems such as internal combustion engine valve train systems. In this study, heat-treated CuBe material was coated with CrN under a micron thickness by cathodic arc physical vapor deposition (arc-PVD) to improve wear resistance not only at unlubricated condition but also at the lubricated condition for tribosystem, especially a material candidate for cam tappets. Therefore, CrN-coated CuBe, CuBe, and AISI52100 steel samples were tested by a tribometer at unlubricated and lubricated sliding conditions. Surface morphological changes and tribochemical formation were investigated by optical microscope, optical profilometer, atomic force microscope, and scanning electron microscope. The results showed that CrN increased the wear resistance of the CuBe significantly, and it can be used as cam tappet material both on unlubricated and boundary lubrication regimes.