The W-cluster reactive sites interaction model for WDLC coatings with ionic liquids

Arshad, Muhammad Shahid (author), Čoga, Lucija (author), Geue, Thomas M. (author), Kovač, Janez (author), Cruz, Sandra M.A. (author), Kalin, Mitjan (author)

This study investigates the use of 1,3-dimethylimidazolium dimethylphosphate ionic liquid (IL) additive in glycerol base oil for improving the lubrication-properties of tungsten-doped diamond-like carbon (WDLC) coatings. Tribological tests were conducted at various applied loads (5 N, 10 N, 20 N) and elevated temperature (100 °C), and the addition of 1 wt% of IL resulted in a significant reduction (∼50%) in friction-coefficient. In-situ neutron-reflectometry analysis revealed a multi-step tribofilm formation mechanism involving IL and W-clusters, resulting in the formation of a 1.24-nm thick tribofilm on the WDLC surface within the first 30-minutes of the friction experiment. The reaction kinetics for tribofilm formation are discussed involving dissociation of dimethylphosphate into dioxo-phosphate, which interacts with W-clusters to form tungsten phosphates and cations adsorbed on their surface.

• Language: English
• Keywords: W-doping DLC coatings, ionic-liquid, friction, neutron reflectometry
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2023
• Number of pages: 11 str.
• Numbering: Vol. 185, art. 108550
• PID: 20.500.12556/RUL-145655
• UDC: 539.92
• ISSN on article: 0301-679X
• DOI: 10.1016/j.triboint.2023.108550
• COBISS.SI-ID: 150840579
• Publication date in RUL: 04.05.2023

Record is a part of a journal

• Title: Tribology international
• Shortened title: Tribol. int.
• Publisher: Elsevier
• ISSN: 0301-679X
• COBISS.SI-ID: 26558976

Licences

• License: CC BY-NC-ND 4.0, Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
• Link: http://creativecommons.org/licenses/by-nc-nd/4.0/
• Description: The most restrictive Creative Commons license. This only allows people to download and share the work for no commercial gain and for no other purposes.

Secondary language

• Language: Slovenian
• Keywords: W-doping DLC premazi, ionska tekočina, trenje, nevtronska reflektometrija