Phononic origin of structural lubrication  

作　　者：Yun DONG Yongkang WANG Zaoqi DUAN Shuyu HUANG Yi TAO Xi LU Yan ZHANG Yajing KAN Zhiyong WEI Deyu LI Yunfei CHEN 

机构地区：[1]Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments,School of Mechanical Engineering,Southeast University,Nanjing,211189,China [2]Department of Mechanical Engineering,Vanderbilt University,Nashville,37235-1592,USA

出　　处：《Friction》2023年第6期966-976,共11页摩擦（英文版）

基　　金：National Natural Science Foundation of China(Grant Nos.52035003,52065037,51575104,and 52175161);the China Postdoctoral Science Foundation(Grant No.2021MD703810);the Postdoctoral Science Foundation of Gansu Academy of Sciences(Grant No.BSH202101);the Southeast University“Zhongying Young Scholars”Project for financial support.

摘　　要：Atomistic mechanisms of frictional energy dissipation have attracted significant attention.However,the dynamics of phonon excitation and dissipation remain elusive for many friction processes.Through systematic fast Fourier transform(FFT)analyses of the frictional signals as a silicon tip sliding over a graphite surface at different angles and velocities,we experimentally demonstrate that friction mainly excites non-equilibrium phonons at the washboard frequency and its harmonics.Using molecular dynamics(MD)simulations,we further disclose the phononic origin of structural lubrication,i.e.,the drastic reduction of friction force as the contact angle between two commensurate surfaces changes.In commensurate contacting states,friction excites a large amount of phonons at the washboard frequency and many orders of its harmonics that perfectly match each other in the sliding tip and substrate,while for incommensurate cases,only limited phonons are generated at mismatched washboard frequencies and few low order harmonics in the tip and substrate.

关 键 词：phononic friction washboard frequency structural lubrication commensurate and incommensurate interfaces 

分 类 号：TH117[机械工程—机械设计及理论]