Tribology performance of diamond-like carbon films on polyether-ether-ketone surfaces

Abstract

Diamond-like carbon films were deposited on the polymer PEEK surface using a magnetron sputtering system. Experiments were conducted under varying rotational friction speed conditions. Special attention was devoted to assessing the surface condition of spherical spots post-friction experiments. Optical microscopy, friction tester, Raman spectroscopy, XPS analysis, and atomic force microscopy were employed to examine film surface morphology, atomic bonding structure, and surface roughness. The results indicate that thin film wear trace exhibits a graphitization trend that increases and then decreases, peaking around 350 rpm (0.11 m/s). Conversely, for spherical spots, the graphitization pattern is the opposite, suggesting a higher degree of disorder in the transferred film on these spots. XPS analysis reveals multiple chemical bonding structures between carbon and oxygen elements on the spherical spots. Notably, under the optical microscope, spherical spots exhibit clear directional alignment, which is absent on the film surface. This study introduces an innovative approach for producing diamond-like carbon films with lubricating and anti-wear properties. It also provides guidance for designing high-performance polymer tribo-systems in industrial applications.