DRY SLIDING FRICTION and WEAR PROPERTIES of CACO3 NANOPARTICLE FILLED EPOXY/CARBON FIBER COMPOSITES

Abstract

Metal/Fiber reinforced polymer (FRP) composite joints with lower friction coefficients are increasingly replacing metal-metal couples in a variety of fields. The wear performance of metal / FRP tribo-contacts becomes a key design parameter for their service life and the improvement in the wear performance of metal-FRP friction pairs is needed to extend their applications. In this paper, sliding friction and wear characteristics of carbon fiber reinforced epoxy composites against metallic counterparts were investigated. Tests were performed on a ball-on-disk tester at a constant normal load and velocity against chromium steel under dry ambient. Moreover, CaCO3 nano reinforcements were introduced into carbon/epoxy composites to improve their wear performance. The coefficient of friction (65%) and the specific wear rate (75%) were drastically reduced with the addition of CaCO3 nano reinforcements. Worn surfaces were analyzed by scanning electron microscopy (SEM) to evaluate the wear mechanisms. It was concluded that the abrasion dominated wear mechanism of the bare carbon/epoxy composites transformed into adhesion for the multi-scale composites which are responsible for the increased wear performance. This impact was most likely attributed to two main factors: spherical CaCO3 particles facilitate sliding and act as a solid lubricant.