Tribological properties of spherical and mesoporous NiAl particles as ionic liquid additives

Abstract

In this study, spherical and mesoporous NiAl particles (abbreviated as sNiAl and mNiAl) were introduced as lubricant additives into two alkyl-imidazolium ionic liquids (ILs) (1-butyl-3-methylimidazolium tetrafluoroborate (LB104) and 1-butyl-3-methyl imidazolium hexafluorophosphate (LP104)) to explore their tribological properties. The sNiAl and mNiAl particles were modified in-situ by anion and cation moieties of ILs through chemical interaction, thereby enhancing their dispersibility and stability in ILs. The mNiAl particles have better dispersibility than the sNiAl ones in ILs because of high specific surface area. LP104-modified sNiAl particles show better friction reduction and wear resistance, mainly relying on the synergy of the hybrid lubricant. These particles form a protective layer that prevents friction pairs from straight asperity contact and improves the tribological behaviors.