Superlubricity of TiN coating using glycerol with the addition of Cu nanoparticles. (March 2023)

• Record Type: Journal Article
• Authors: Fu, Xiaojing; Guo, Shuming; Wan, Yong; Zheng, Changsheng; Li, Qiang; Liu, Bingchang
• Is Part Of: Tribology international. Volume 181(2023)
• Publication Date: 2023-03
• Subjects: TiN coating -- Cu nanoparticles -- Lubrication -- Carbon-based tribofilm -- Superlubricity; Tribology -- Periodicals; 621.89
• DOI: 10.1016/j.triboint.2023.108327
• Languages: English
• ISSNs: 0301-679X

Abstract

Abstract: Superlubricity was achieved by the addition of copper nanoparticles (CuNPs) as an additive to glycerol, a sustainable lubricant, which was applied to TiN-coated steel that underwent ball-on-flat reciprocating testing at an average contact pressure of 54.6 MPa. A coefficient of friction of ∼ 0.007 and a wear rate of 2.0 × 10 –8 mm 3 /N m were achieved on the TiN coating when lubricated with glycerol + 0.1 wt% CuNPs at a sliding speed of 120 mm/s. XPS and Raman analysis suggested that a surface tribofilm containing CuNPs and a carbon-based film derived from the degradation of glycerol were deposited onto the contact area of the tribopairs, which effectively prevented the direct asperity contact between the steel ball and TiN-coated steel, enabling ultra-low friction. Highlights: CuNPs were added in glycerol for reducing friction and wear of TiN-steel pairs. Macroscale ultra-low friction can be achieved by glycerol + 0.1 wt% CuNPs. CuNPs can tribo-induce the degradation of glycerol to form a carbon-based film. CuNPs were deposited onto the contacting area. Ultra-low friction was enabled by the synergy between CuNPs and glycerol.