In Situ Friction-Induced Graphene Originating from Methanol at the Sliding Interface between the WC Self-Mated Tribo-Pair and Its Tribological Performance

Abstract

Alcohols are reported to have superlubricity at low loads during sliding; however, their lubricity under high loads has rarely been reported. Meanwhile, the lubrication mechanism of alcohols under high loads is still not well understood. Here, we first report the lubricity of methanol under 98 N and 1450 rpm and demonstrate the formation of graphene and fullerene-like nanostructures induced by tribochemical reactions. Results show that the lubrication mechanism was mainly attributed to the friction-induced graphene under boundary lubrication condition. Besides that, the wear rate of a YG8 hard alloy ball mainly occurred at the run-in processes, and the friction-induced graphene effectively inhibited further wear after the run-in processes. The formation mechanism of graphene was well investigated, and the flash temperature rise and catalyst (WC, WO2, and WO3) were the major causes for the formation of graphene.

A fast and high-efficiency electrochemical exfoliation strategy towards antimonene/carbon composites for selective lubrication and sodium–ion storage applications

“…2c exhibits two distinctive peaks near 1391 cm À1 and 1579 cm À1 , which correspond to the D band and G band of amorphous carbon, 29 revealing the formation of a thin carbon layer. 30 The weight concentration of carbon in the antimonene/C composite is measured using thermogravimetric analysis (TGA) as plotted in Fig. 2d.…”

“…where M Sb and M Sb2O4 represent the molecular weight of Sb and Sb 2 O 4 , m Sb2O4 and m composite represent the final weight of Sb 2 O 4 and the initial weight of the antimonene/C composite. [28][29][30][31][32] According to this method, the weight concentration of the Sb element in the antimonene/C composite is calculated to be 60. 2g, the high resolution Sb 3d XPS peak of the antimonene/C composite can be divided into two major spinorbit split doublets splitting about 9.4 eV, 33 and the O 1s peak is overlapped at around 532 eV.…”

“…[44][45][46] Besides, carbon-based materials such as oil and alcohols can be easily transformed to amorphous carbon or graphene during sliding, which can further reduce friction and wear. 30,[47][48][49] The possible tribological mechanism is proposed as plotted in Fig. 8.…”

Achieving Ultralow Friction and Wear by Tribocatalysis: Enabled by In-Operando Formation of Nanocarbon Films

“…118 Alternatively, the MeN-Cu coatings demonstrated great potential for tribocatalytic activation of the protective tribofilms' formation in different alkane environments with the alkane molecule length and wetting characteristics affecting the effectiveness of the film growth and protection. 119 Alkanebased and alcohol-based environments as hydrocarbon sources have also been reported to facilitate the formation of graphenelike structures on tungsten carbide 120,121 and MoS 2 122 surfaces. In addition to the common widely used hydrocarbon sources, the formation of graphitic layers has been detected from proteins of the body fluids in metal-on-metal hip replacements that are made of catalytically active metals such as cobalt and molybdenum, triggering carbon film formation.…”

“…Alternatively, the MeN-Cu coatings demonstrated great potential for tribocatalytic activation of the protective tribofilms’ formation in different alkane environments with the alkane molecule length and wetting characteristics affecting the effectiveness of the film growth and protection . Alkane-based and alcohol-based environments as hydrocarbon sources have also been reported to facilitate the formation of graphene-like structures on tungsten carbide , and MoS 2 surfaces.…”