Contact Damage Resistance and Tribological Behavior of Ceramic/Carbon Nanostructure Composites

Applications of Ceramic/Graphene Composites and Hybrids

“…Accordingly, graphene-based nanostructures have been widely incorporated into polymers, metals and ceramics, because of their excellent lubricating properties [ 278 , 279 ]. Most tribological studies have shown superior response of ceramic/graphene composites, with typical reductions in the friction coefficient in the 50–70% range and increases in wear resistance of few orders of magnitude, although results depend on many experimental factors, such as recent reviews on the subject reveal [ 4 , 280 ]. The improved tribological properties of these composites are generally associated with the formation of a self-lubricant and wear protecting carbon-rich tribofilm well adhered to the tested surface, jointly with an improved fracture toughness that would minimize wear [ 280 ].…”

“…Most tribological studies have shown superior response of ceramic/graphene composites, with typical reductions in the friction coefficient in the 50–70% range and increases in wear resistance of few orders of magnitude, although results depend on many experimental factors, such as recent reviews on the subject reveal [ 4 , 280 ]. The improved tribological properties of these composites are generally associated with the formation of a self-lubricant and wear protecting carbon-rich tribofilm well adhered to the tested surface, jointly with an improved fracture toughness that would minimize wear [ 280 ]. The tribofilm is created by the sliding motion of the counter-bodies, producing the exfoliation and crushing of the pulled-out graphene fillers, which under dry testing conditions could be rolled-up, producing a roller bearing-like effect on the tribofilm top that overall reduces friction and wear [ 281 ].…”

“…The water film between the surfaces jointly with the carbon-based tribofilm induced the better tribological response of these composites for seal face components. The tribological performance under isooctane lubrication of different ceramic/graphene composites were chosen to simulate the conditions attained in gasoline direct injection (GDI) engines [ 4 , 280 ]. It is worth mentioning that Si 3 N 4 /GNP composites containing 20.6 vol.% GNP [ 287 ] reduced ~50% the friction coefficient of the plain ceramics and enhanced its wear resistance up to 63%, hence standing out as an excellent choice for improving GDI system performance.…”