Ionic liquids as lubricants for steel–aluminum contacts at low and elevated temperatures

Room temperature ionic liquids (ILs) are high performance fluids with a wide thermal stability range. In this work we present the first study of ILs as lubricants under a wide range of temperature conditions (−30, 100, and 200 °C). The tribological performance of the imidazolium ionic liquids 1-hexy...

Full description

Saved in:
Bibliographic Details
Published in:Tribology letters 2007-04, Vol.26 (1), p.53-60
Main Authors: Jiménez, Ana-Eva, Bermúdez, María-Dolores
Format: Article
Language:English
Subjects:
Abrasion
Aluminum
Aluminum fluorides
Chains
Debris
Friction
High temperature
Ionic liquids
Ions
Lubricants
Lubrication
Mineral oils
Polarity
Propylene
Solvents
Thermal decomposition
Thermal stability
Tribology
Wear mechanisms
Wear particles
X ray photoelectron spectroscopy
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Room temperature ionic liquids (ILs) are high performance fluids with a wide thermal stability range. In this work we present the first study of ILs as lubricants under a wide range of temperature conditions (−30, 100, and 200 °C). The tribological performance of the imidazolium ionic liquids 1-hexyl, 3-methyl (L106) and 1-octyl, 3-methyl (L108) imidazolium tetrafluoroborates have been compared with that of a mineral oil (MO) and the synthetic ester propylene glycol dioleate (PGDO) in pin-on-disk aluminum–steel contacts. ILs show lower friction and wear values than conventional oils at all temperatures. The lubricating performance depends on thermal stability, polarity of the molecules, their ability to form ordered adsorbed layers and the tribocorrosion processes, which take place at the interface. While the conventional oils MO and PGDO fail above 150 °C due to thermal decomposition, the longer alkyl chain L108 provides an effective surface separation at all temperatures. L108 only shows friction and wear increments at −30 °C in the presence of water, due to severe abrasion. While the more polar, shorter alkyl chain L106 shows severe wear at 200 °C due to aluminum fluoride wear debris formation by tribocorrosion reactions. The time for tribocorrosion to take place has been determined from friction increments and wear debris generation. Wear mechanisms are discussed on the basis of SEM, EDS, and XPS results.
ISSN:1023-8883
1573-2711
DOI:10.1007/s11249-006-9182-9