Study of Tribological Properties of Fullerenol and Nanodiamonds as Additives in Water-Based Lubricants for Amorphous Carbon (a-C) Coatings

Abstract

The tribological performances of fullerenol and nanodiamonds (NDs) as additives in water-based lubricants for amorphous carbon (a-C) coatings are investigated to avoid disadvantage factors, such as chemical reactions and deformation of particles. The effects of size and additive amount on tribological properties of nanoparticles are studied by rigid nanoparticles within the dot size range. The results show that owing to its small particle size (1–2 nm), fullerenol cannot prevent direct contact of the friction pair at low concentration conditions. Only when the quantity of fullerenol increased to support the asperity contact loads in sufficient concentration did nano-bearings perform well in anti-friction and anti-wear effects. Unlike fullerenol, nanodiamond particles with a diameter of about 5–10 nm show friction-reducing effect based on the nano-bearing effects at ultra-low concentration (0.01 wt.%), whereas particles at higher concentration block the rolling movement, hence increasing the coefficient of friction (COF) and wear. As a result of the effect of difference in size, fullerenol provides a better overall lubrication, but it is hard to reach a friction coefficient as low as NDs even under the optimal conditions.

Tribological Properties of Nano-Scale Al2O3 Particles with Different Shapes as Lubricating Oil Additives

“…However, the irregular-shaped Al2O3 nanoparticles do not show a significant improvement in friction pa ern (Figures 8c). The spherical and rod-shaped nanoparticles behave like nano-bearings, converting sliding friction into rolling friction (Figure 8d,e) [24]. But, there is significant difference in tribological performance between spherical and rod-shaped nanoparticles, which may be due to differences in contact.…”

Synergistic Lubricating Performance of Graphene Oxide and Modified Biodiesel Soot as Water Additives

“…Carbon nanomaterials have recently attracted extensive attention for use as lubricating additives in water [7]. Some carbon nanomaterials, such as carbon quantum dots, onionlike carbon, graphene, nanodiamonds, and carbon nanotubes, have been explored for the development of water-based lubricating additives owing to their unique physical and chemical properties [8][9][10][11].…”