Effects of magnetic ionic liquid as a lubricant on the friction and wear behavior of a steel-steel sliding contact under elevated temperatures

Abstract

A magnetic ionic liquid (abridged as MIL) [C 6 mim] 5 [Dy(SCN) 8 ] was prepared and used as the magnetic lubricant of a steel-steel sliding pair. The tribological properties of the as-prepared MIL were evaluated with a commercially obtained magnetic fluid lubricant (abridged as MF; the mixture of dioctyl sebacate and Fe 3 O 4 , denoted as DIOS-Fe 3 O 4 ) as a control. The lubrication mechanisms of the two types of magnetic lubricants were discussed in relation to worn surface analyses by SEM-EDS, XPS, and profilometry, as well as measurement of the electric contact resistance of the rubbed steel surfaces. The results revealed that the MIL exhibits better friction-reducing and antiwear performances than the as-received MF under varying test temperatures and loads. This is because the MIL participates in tribochemical reactions during the sliding process, and forms a boundary lubrication film composed of Dy 2 O 3 , FeS, FeSO 4 , nitrogen-containing organics, and thioether on the rubbed disk surface, thereby reducing the friction and wear of the frictional pair. However, the MF is unable to form a lubricating film on the surface of the rubbed steel at 25 °C , though it can form a boundary film consisting of Fe 3 O 4 and a small amount of organics under high temperature. Furthermore, the excessive Fe 3 O 4 particulates that accumulate in the sliding zone may lead to enhanced abrasive wear of the sliding pair.

Surfactant-Modified Silica Nanoparticles-Stabilized Magnetic Polydimethylsiloxane-in-Water Pickering Emulsions for Lubrication and Anticorrosion

“…Liquid lubricants with magneto-responsiveness possess unique capabilities in continuous lubrication by rapidly filling up the depressions on a worn surface under an external magnetic field and, meanwhile, validly eliminating lubricant leakage by overcoming the gravitational effect during the lubrication process. − However, preparation of a magnetic emulsion with the attributes of simple component, long-term stability, reversible emulsification and demulsification, and effective lubrication and anticorrosion is challenging, because it usually requires a relatively complicated synthesis procedure to fabricate composite magnetic particles that can fulfill these functional demands. In recent years, the creation of magnetic surfactants, which consist of long-chain alkyl organic cations and Fe­(III)-, Ce­(III)-, Gd­(III)-, or Ho­(III)-based complex inorganic magnetic anions, has provided approaches alternative to magnetic particles for producing ferro-fluids or composite magnetic nanostructures. − The advantages of employing magnetic surfactants over particles lie upon their facile preparation, good dispersibility and stability in solutions, fast and effective binding onto silica particles via electrostatic interaction, and lubricative and anticorrosive properties due to their cationic surfactant nature. − Therefore, the hybridization of magnetic surfactants with silica nanoparticles exhibits a great potential in creating versatile composite nanoparticles for preparing a magnetic Pickering emulsion with the aforementioned performances.…”

Typical dampers and energy harvesters based on characteristics of ferrofluids

“…In 1965, Stephen [1] from National Aeronautics and Space Administration (NASA) successfully prepared stable ferrofluids for the first time, after which many of the properties of ferrofluids were investigated, including their levitation characteristics [2,3], rheological properties [4,5], magnetization characteristics [6], magnetoviscous effect [7,8], magnetocaloric effect [9,10], and magneto-optic effect [11,12]. Ferrofluids have a wide range of industrial applications such as seals [13][14][15], dampers, sensors [16,17], lubrication [18][19][20], biomedicine [21], and finishing [22,23]. Although the statistics are incomplete, there are more than 170 applications for ferrofluids, many of which cannot utilize other materials.…”

Electroosmotic modulated unsteady squeezing flow with temperature-dependent thermal conductivity, electric and magnetic field effects

“…The analysis of magnetic squeezing films requires magnetohydrodynamics (MHD) in which the Navier-Stokes viscous flow model is augmented with appropriate magnetic body force terms. Many researchers have explored novel configurations for magnetic tribological flows owing to recent developments in more stable magnetic suspensions which are finding applications in steel-steel sliding damper applications [10], spacecraft landing gear and seismic isolation devices [11], multi-stage magnetic fluid seal systems [12] and rocket turbo pump seals [13]. Naduvinamani et al [14] studied analytically the influence of static axial magnetic field and surface roughness on the couple stress magnetized lubricant squeeze film between circular stepped plates.…”