1. State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
2. Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
3. Novelis Global Research and Technology Center, Kennesaw, Georgia 30144, United States
4. Tribology of Materials Research Centre, Department of Mechanical, Automotive & Materials Engineering, University of Windsor, Windsor, Ontario N9B 3P4, Canada