Ultralow-Friction and Ultralow-Wear TiN-Ag Solid Solution Coating in Base Oil
Chang Liu, Xinlei Gu, Lina Yang, Xianqi Song, Mao Wen, Jia Wang, Quan Li, Kan Zhang, Weitao Zheng, Changfeng Chen
Abstract
Lubrication plays a pivotal role in reducing energy consumption and machinery wear, profoundly impacting technological and economic development and the environment. A recent study (Erdemir, A., et al. Nature 2016, 536, 67) reported the effective extraction of carbon-based tribofilms from lubricating oil by catalytic activation of the coating material, opening new possibilities for innovative lubrication material research and development. Here, we showcase a solute-atom-strengthened and catalytically functionalized coating design and demonstrate its implementation in a TiN-Ag solid solution film that exhibits concurrent ultralow friction and ultralow wear. Indentation tests and Raman and X-ray photoelectron spectroscopy combined with quantum mechanical simulations uncover the rare superhard nature of the TiN-Ag film along with a solute-Ag-atom-induced self-oxidation mechanism for its outstanding catalytic capacity. These findings identify an outstanding type of mechanically strong and catalytically active coating material with simultaneous superior protective and lubricating functionality, holding great promise for applications ranging from microdevices to large-scale industrial equipment.