Running-in behavior of a H‒DLC/Al_(2)O_(3) pair at the nanoscale  

作　　者：Pengfei SHI Junhui SUN Yunhai LIU Bin ZHANG Junyan ZHANG Lei CHEN Linmao QIAN 

机构地区：[1]Tribology Research Institute,State Key Laboratory of Traction Power,Southwest Jiaotong University,Chengdu 610031,China [2]State Key Laboratory of Solid Lubrication,Lanzhou Institute of Chemical Physics,Chinese Academy of Sciences,Lanzhou 730000,China

出　　处：《Friction》2021年第6期1464-1473,共10页摩擦（英文版）

基　　金：The authors are grateful for the financial support from the National Natural Science Foundation of China(51875486 and 51991373);Sichuan Science and Technology Program(2019YFH0098).

摘　　要：Diamond-like carbon(DLC)film has been developed as an extremely effective lubricant to reduce energy dissipation;however,most films should undergo running-in to achieve a super-low friction state.In this study,the running-in behaviors of an H–DLC/Al_(2)O_(3) pair were investigated through a controllable single-asperity contact study using an atomic force microscope.This study presents direct evidence that illustrates the role of transfer layer formation and oxide layer removal in the friction reduction during running-in.After 200 sliding cycles,a thin transfer layer was formed on the Al2O3 tip.Compared with a clean tip,this modified tip showed a significantly lower adhesion force and friction force on the original H–DLC film,which confirmed the contribution of the transfer layer formation in the friction reduction during running-in.It was also found that the friction coefficient of the H–DLC/Al_(2)O_(3) pair decreased linearly as the oxygen concentration of the H–DLC substrate surface decreased.This phenomenon can be explained by a change in the contact surface from an oxygen termination with strong hydrogen bond interactions to a hydrogen termination with weak van der Waals interactions.These results provide new insights that quantitatively reveal the running-in mechanism at the nanoscale,which may help with the design optimization of DLC films for different environmental applications.

关 键 词：hydrogenated diamond-like carbon(H–DLC)film RUNNING-IN NANOSCALE oxide film transfer layer 

分 类 号：TB383.2[一般工业技术—材料科学与工程]