Ultralow Friction and Wear of Polymer Composites under Extreme Unlubricated Sliding Conditions

Abstract

Dependence of the tribological behaviors of polyimide‐ and polyetheretherketone‐based composites on pv (pressure × speed) factors is investigated in air ambience. It is demonstrated that the hybrid composites filled with nanosilica/carbon fibers/graphite exhibit ultralow friction and wear under extreme conditions. In particular, the friction coefficients of the hybrid nanocomposites at 40 MPa m s−1 are in the range of 0.03–0.04, which are even lower than those obtained with poly alpha olefin lubrication. Moreover, the friction coefficients are lower than those of carbon fibers reinforced polymer composites ever reported in literatures. In order to reveal the underlying mechanisms of ultralow friction and wear, tribochemistry and tribofilms' nanostructures are comprehensively analyzed. It is identified that chelation of polymeric molecular radicals with steel counterface occurs enhancing tribofilm's bonding strength. Striking orientation of the molecules of remnant polymer in tribofilm is indicative that the film exhibits an easy‐to‐shear characteristic under extreme pv conditions. Nanosilica released onto sliding interface and iron oxide particles abraded from the counterface are thereafter tribosintered into a compact layer, which accounts for the high load‐carrying capability of the tribofilm.

Development and optimization of high‐performance PEEK/CF/Nanosilica hybrid composites

“…As mentioned above, PEEK/CF‐N2 exhibits the best tribological performance in the studied range. Its friction coefficient and specific wear rate are similar to those of a high‐performance PEEK‐tribocomposite under extreme pv‐conditions reported in the literature, 33 which is filled with 10 vol.% carbon fiber, 8 vol.% solid lubricant, and 2 vol.% nanosilica. However, this tribocomposite presents much higher mechanical properties due to the high amount of carbon fibers (Figure 3A,B).…”

A review on tribology of polymer composite coatings

“…The column of friction coefficient in Table 3 also describes the change in the friction coefficient with the filler content. For example, the friction coefficient and wear rate of epoxy/graphene composite coatings decreases with an increase in the graphene content from 0 to 4 wt% [154]. The friction coefficient of the epoxy/zinc sulfide-modified carbon nanotube composite coating [77] decreases first and then increases, reaching the lowest coefficient at 1.25 wt% (Figs.…”

Novel phenylboronic acid derivatives containing phosphorous and nitrogen as lubricant additives: Synthesis, characterization, and tribological behaviors

“…Friction and wear will cause energy consumption, environment issue, and fault of mechanical system. 1,2 In industrial applications, the appropriate additive in lubricating oil can dramatically increase machine efficiency, reduce material consumption, and minimize unwanted friction and wear. 3,4 Various types of lubricant additives have been widely used in lubrication area because of their remarkable properties such as oxidation inhibition, anti-wear, and antifriction capabilities.…”