Effects of power on tribological and mechanical properties of diamond-like carbon film modified nitrile butadiene rubber

Abstract

This study aims to improve the wear resistance of nitrile butadiene rubber (NBR) by depositing diamond-like carbon (DLC) films using Direct Current Magnetron Sputtering (DC-MS), a simple and cost-effective technique. DC-MS is a coating process that uses a direct current to generate an electric field and sputter conductive materials from a target to a substrate. A magnetic field enhances the plasma density and sputtering rate. The study examines the bonding force, surface morphology, tribological properties, and mechanical strength of DLC. Scanning electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy are used to characterize the cross-sectional morphology, structural features, and chemical bonding species of DLC films and NBR substrates. Nanoindentation results show that varying the power has no significant effect on hardness and Young’s modulus. Tribological tests are conducted under ambient conditions using a ball-and-disk tribometer, with a fixed load of 0.3 N. Results indicate that the power of DLC films influences their tribological properties. Specifically, DLC films prepared at 120 W exhibit superior tribological properties, maintaining a stable coefficient of friction (CoF) below 0.2 for the test duration. These findings have promising implications for their application.