Pacific Rim Symposium on Surfaces, Coatings and Interfaces (PacSurf 2018)
    Thin Films Tuesday Sessions
       Session TF-TuP

Paper TF-TuP3
Graphite Tribofilm Extracted from Base Oil by Self-Oxidizing Coating: A Highway for Friction and Wear Reduction

Tuesday, December 4, 2018, 4:00 pm, Room Naupaka Salon 1-3

Session: Thin Films Poster Session I
Presenter: Lina Yang, State Key Laboratory of Superhard Materials, Department of Materials Science and Key Laboratory of Automobile Materials, MOE, Jilin University, Changchun 130012, People's Republic of China., China
Authors: L. Yang, State Key Laboratory of Superhard Materials, Department of Materials Science and Key Laboratory of Automobile Materials, MOE, Jilin University, Changchun 130012, People's Republic of China., China
K. Zhang, State Key Laboratory of Superhard Materials, Department of Materials Science and Key Laboratory of Automobile Materials, MOE, Jilin University, Changchun 130012, People's Republic of China
Correspondent: Click to Email

Tailoring sliding interface is a vital pathway to minimize friction and wear, commonly, either fluid layers or solid tribofilms have been employed. Herein, the lubricating effects from both ones are combined via in situ formation of graphite tribofilm extracted from PAO base oil (without additives) when introduced catalytic TiN coating enabled by solute Ag atoms (super-hard nature). In this way, superior tribological properties with ultralow friction coefficient at 0.075 and wear rate at 2.28×10-11 mm3/Nm can be obtained. Better yet, the incorporation of solute Ag atoms into TiN structure could induce a charge depletion state and active surface self-oxidation to a special Ag2O/TiO2 composite, as demonstrated by electron localization function (ELF) and XPS. Different from traditional metal catalysts, such metallic oxides from solid solution structure are suggested to dominant this catalyst and extraction action. Besides, the direct transfer of part of electrons from the unstable charge structure to oil molecules further ensures the catalytic effect. This study highlights the crucial role of solid solution coating in catalyzing and extracting tribofilms from lubricating oil, which would be a new insight towards a more efficient lubricating system.