Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Understanding Tribofilm Formation Mechanisms in Ionic Liquid Lubrication

Journal Article · · Scientific Reports
 [1];  [1];  [2];  [1]
  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science & Technology Division
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Science (CNMS)
Ionic liquids (ILs) have recently been developed as a novel class of lubricant anti-wear (AW) additives, but the formation mechanism of their wear protective tribofilms is not yet well understood. Unlike the conventional metal-containing AW additives that self-react to grow a tribofilm, the metal-free ILs require a supplier of metal cations in the tribofilm growth. The two apparent sources of metal cations are the contact surface and the wear debris, and the latter contains important ‘historical’ interface information but often is overlooked. We correlated the morphological and compositional characteristics of tribofilms and wear debris from an IL-lubricated steel–steel contact. In conclusion, a complete multi-step formation mechanism is proposed for the tribofilm of metal-free AW additives, including direct tribochemical reactions between the metallic contact surface with oxygen to form an oxide interlayer, wear debris generation and breakdown, tribofilm growth via mechanical deposition, chemical deposition, and oxygen diffusion.
Research Organization:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Vehicle Technologies Office (EE-3V)
Grant/Contract Number:
AC05-00OR22725
OSTI ID:
1408612
Journal Information:
Scientific Reports, Journal Name: Scientific Reports Journal Issue: 1 Vol. 7; ISSN 2045-2322
Publisher:
Nature Publishing GroupCopyright Statement
Country of Publication:
United States
Language:
English

References (33)

Synergistic Effects Between Phosphonium-Alkylphosphate Ionic Liquids and Zinc Dialkyldithiophosphate (ZDDP) as Lubricant Additives journal July 2015
Does the Use of Diamond-Like Carbon Coating and Organophosphate Lubricant Additive Together Cause Excessive Tribochemical Material Removal? journal August 2015
Tertiary and Quaternary Ammonium-Phosphate Ionic Liquids as Lubricant Additives journal June 2016
The nature and origin of wear particles from boundary lubrication with a zinc dialkyl dithiophosphate journal January 1984
Some kinetic aspects of extreme pressure lubrication journal March 1986
Boundary lubrication with anti-wear additives: study of interface film formation by electrical contact resistance journal October 1979
Tribological behavior and nature of tribofilms generated from fluorinated ZDDP in comparison to ZDDP under extreme pressure conditions—Part II: Morphology and nanoscale properties of tribofilms journal March 2011
Comparison of an oil-miscible ionic liquid and ZDDP as a lubricant anti-wear additive journal March 2014
Properties of tribofilms formed with ashless dithiophosphate and zinc dialkyl dithiophosphate under extreme pressure conditions journal February 2010
Oil-miscible and non-corrosive phosphonium-based ionic liquids as candidate lubricant additives journal June 2012
Comparison of the tribological behavior of steel–steel and Si3N4–steel contacts in lubricants with ZDDP or ionic liquid journal November 2014
A comparative experimental study on the use of acoustic emission and vibration analysis for bearing defect identification and estimation of defect size journal October 2006
A method of temperature monitoring in fluid film bearings journal February 2004
Ionic Liquids as Lubricant Additives: A Review journal January 2017
Phosphonium-Organophosphate Ionic Liquids as Lubricant Additives: Effects of Cation Structure on Physicochemical and Tribological Characteristics journal December 2014
Ionic Liquids Composed of Phosphonium Cations and Organophosphate, Carboxylate, and Sulfonate Anions as Lubricant Antiwear Additives journal October 2014
The History and Mechanisms of ZDDP journal October 2004
The origin of anti-wear chemistry of ZDDP journal January 2012
Experimental and Molecular Dynamics Simulations of Tribochemical Reactions with ZDDP: Zinc Phosphate–Iron Oxide Reaction journal September 2008
Molecular Mechanisms for the Functionality of Lubricant Additives journal March 2005
Mechanisms of antiwear tribofilm growth revealed in situ by single-asperity sliding contacts journal March 2015
Impact of Lubricant Additives on thePhysicochemical Properties and Activity of Three‐Way Catalysts journal April 2016
Boundary lubrication with anti-wear additives: study of interface film formation by electrical contact resistance journal October 1979
Wear monitoring based on the analysis of lubricant contamination by optical ferroanalyzer journal August 2003
The significance and use of the friction coefficient journal September 2001
A method of temperature monitoring in fluid film bearings journal February 2004
Road tests of oil condition sensor and sensing technique journal March 2001
Tribological behavior and nature of tribofilms generated from fluorinated ZDDP in comparison to ZDDP under extreme pressure conditions—Part 1: Structure and chemistry of tribofilms journal March 2011
Characterization of ZDDP and ionic liquid tribofilms on non-metallic coatings providing insights of tribofilm formation mechanisms journal May 2015
Antiwear film formation of neutral and basic ZDDP: influence of the reaction temperature and of the concentration journal January 2000
The History and Mechanisms of ZDDP journal October 2004
Ball Bearing Lubrication (The Elastohydrodynamics of Elliptical Contacts) journal April 1982
Mechanical Tribology book April 2004

Cited By (1)

Reactivity of oil‐soluble IL with silicon surface at elevated temperature journal March 2019

Similar Records

Is more always better? Tribofilm evolution and tribological behavior impacted by the concentration of ZDDP, ionic liquid, and ZDDP-Ionic liquid combination
Journal Article · Fri Jul 05 20:00:00 EDT 2019 · Wear · OSTI ID:1559704

Atom Probe Tomography Unveils Formation Mechanisms of Wear-Protective Tribofilms by ZDDP, Ionic Liquid, and Their Combination
Journal Article · Mon Jun 19 20:00:00 EDT 2017 · ACS Applied Materials and Interfaces · OSTI ID:1376428

Ultralow Boundary Lubrication Friction by Three-Way Synergistic Interactions among Ionic Liquid, Friction Modifier, and Dispersant
Journal Article · Wed Mar 18 20:00:00 EDT 2020 · ACS Applied Materials and Interfaces · OSTI ID:1616831