This review focuses on the effect of metal-containing nanomaterials on tribological performance in oil lubrication. The basic data on nanolubricants based on nanoparticles of metals, metal oxides, metal sulfides, nanocomposities, and rare-earth compounds are generalized. The influence of nanoparticle size, morphology, surface functionalization, and concentration on friction and wear is analyzed. The lubrication mechanisms of nanolubricants are discussed. The problems and prospects for the development of metal-containing nanomaterials as lubricant additives are considered. The bibliography includes articles published during the last five years. Friction 7(2): 93-116 (2019) | https://mc03.manuscriptcentral.com/friction Friction 7(2): 93-116 (2019) 97 |www.Springer.com/journal/40544 | Friction http://friction.tsinghuajournals.comFriction 7(2): 93-116 (2019)

No abstract

No abstract

Over the last decades, conjugated thermolysis of metal chelate monomers (MCMs) has been widely used to produce various metal and metal oxide nanostructures. In the present study, a detailed analysis of the conjugate thermolysis of MCM based on cobalt(II) acrylate (Acr) complexes with 2,2′‐bipyridine (bpy) and 1,10‐phenanthroline (phen) was carried out. The main stages and kinetics features of conjugated thermolysis of MCMs are estimated. Metal‐polymer nanocomposites containing metal nanoparticles (NPs) uniformly distributed in a stabilizing nitrogen‐containing polymer matrix and Co3O4 NPs are obtained depending on the conditions of conjugated thermolysis. The composition, structure and properties of the nanomaterials obtained were studied using X‐ray diffraction (XRD), IR spectroscopy, atomic force microscopy (AFM), scanning electron microscopy (SEM), energy dispersive X‐ray spectroscopy (EDS) and thermal analysis (TA). Analysis of Co3O4 NPs as lubricant additives was carried out in the perspective of their tribological behavior using a pin‐on‐disc tribometer. At an optimum concentration of NPs, the coefficient of friction is the lowest. When the level of NPs increases above the optimum level, the coefficient of friction increases. With an increase in the load to 196 N, the coefficient of friction decreases with increasing concentration.

Nickel nanoparticles with sizes from 12 to 34 nm were obtained by pyrolysis of nickel formate. They have been used as additives to the low-temperature grease (CIATIM-201). Studies of tribotechnical properties have shown that the CIATIM-201 with nickel additives at concentrations of 0.05 wt. % -0.2 wt. % has the best antiwear and extreme pressure properties in comparison with pure grease. Friction surfaces were characterised by the methods of atomic-force microscopy AFM (PHYWE), 3D optical microscopy and indentation tests. The improvement of tribotechnical properties of grease is related to the process of micro-polishing, which leads to the formation of a structural layer with a high modulus of elasticity on the friction surface.