The Effect of Nano Graphite Particle Content on the Wear Behaviour of ZA27 Based Hybrid Composites

Abstract

ZA27 based hybrid composites with dry lubricating particles and hard particles can be used for bearing applications with their good tribological properties instead of the traditional bearing materials. In this study, the wear behaviour of ZA27 based hybrid composites reinforced nano-graphite particulates and hard nano-alumina (Al2O3) particulates were investigated under dry sliding conditions. While the content of nano-alumina that is one of reinforced materials was selected in 4 vol. %, the contents of nano-graphite particulates were determined in different volumes (%1-%2-%3 and %4). The effect of graphite content was studied on wear behaviour under different sliding distance conditions. A block-on-disc sliding wear testing apparatus was used to carry out dry wear tests. The sliding distances was found to be significant parameter detecting effect of graphite content. The worn surfaces were investigated by scanning electron microscopy (SEM) and the wear mechanisms were identified. While the lowest wear loss was seen in hybrid nanocomposite with content of 4 vol. % graphite and 4 vol. % alumina, the highest wear loss was determined in ZA27. It was determined that abrasion is the dominant mechanism in all hybrid nanocomposites except for composite including 4 vol. % graphite and 4 vol. % alumina. However, the worn surface of the hybrid nanocomposite that is with content of 4 vol. % graphite and 4 vol. % alumina showed that adhesion is dominant as the wear mechanism.