Investigation of the Mending Effect and Mechanism of Copper Nano-Particles on a Tribologically Stressed Surface

Abstract

The mending effect and mechanism of metal nano-particles in an area undergoing wear are quite important for both the fundamental theory of nano-tribology and the development of lubricant additives. This paper presents research on the mending effect of copper nano-particles added to lubricant oil. Pin-on-disk experiments and Scanning Electron Microscopy (SEM) observations show that copper nano-particles do display an excellent mending effect. The observation by Scanning Tunnelling Microscopy (STM) reveals that the mending effect results from the deposition of copper nano-particles onto the wear scar. It has also been disclosed by heating simulation that, due to nano-scale effects, which bring about decrease in the diffusion temperature of copper nano-particles, the heat generated by friction leads to the diffusion of copper nano-particles and their subsequent deposition, which finally results in the so-called mending effect.

Tribological investigation of diamond nanoparticles for steel/steel contacts in boundary lubrication regime

“…Chou and Lee (2010) reported that the wear mechanism for steel/aluminum alloy contacts is entirely different from steel/steel contacts. However, in most of the cases, the improvement in tribological properties is due to the ball bearing effect (Wu et al 2007), mending effect (Liu et al 2004;Ç elik et al 2013), polishing effect (Nunn et al 2015) and protective film formation capabilities (Battez et al 2007;Alves et al 2016) of different nanoparticles.…”

Nanotoxicity: Dimensional and Morphological Concerns

“…The sensitive targets of copper toxicity, after oral exposure, include the gastrointestinal system, liver, and kidneys. The manifestation of Cu poisoning mainly includes drowsiness and anorexia in the early stages [140,141] as well as disruption of the epithelial lining of the gastrointestinal tract, hepatocellular necrosis, and acute tubular necrosis in the kidney [142]. Copper nanoparticles have shown great promise as osteoporosis-treatment drugs, antibacterial materials, additives in livestock and poultry feed, and intrauterine contraceptive devices.…”

Researches on Tie Rod Ends Lubricated by Grease with TiO2 and ZrO2 Nanoparticles

“…Further studies, described in [6][7][8], show that nanoparticle additives can also form a protective film over friction surfaces. Study [9] describes the formation of nanoparticle additive depositions on contact surfaces which compensate the loss of material. Nanoparticle additives can also reduce the roughness of contact surfaces due to their abrasive action as described in [10].…”