Tribological studies of epoxy-carbon nanofiber composites - Effect of nanofiber alignment using AC electric field

In this study, an electric field was applied to align carbon nanofibers (CNF) in an epoxy matrix and the tribological performances were evaluated. The epoxy/aligned CNF composites were fabricated with different weight percentages of non-functionalized CNFs (0.2-2 wt%) with which friction and wear tests were carried out keeping sliding direction normal to fiber orientation. The wear resistance of 1 wt% random and aligned composites improved by 3.5 and 25 times, respectively, compared to pure epoxy (20 N load). Moreover, the friction coefficient reduced from 0.6 for pure epoxy to 0.44 and 0.24 for random and aligned CNF/epoxy composites, respectively. Improved thermal stability, normal load carrying capacity and lubricating effect of CNFs contributed to the superior wear resistance of aligned composites.