Abstract Observation of partial interface slip prior to sliding is reported in micrometre-scale single asperity contacts formed of diamond tips and various substrate materials. Using a dual-axis nanoindenter, an increasing oscillating lateral load is applied to contacts indented under constant normal load. Lateral load-displacement curves are extracted, with partial slip signalled by a steady decrease in contact stiffness as the magnitude of oscillation increases, dropping to zero during sliding. Both elastic and plastic contacts are examined, and contact radii from 215-485 nm. An interfacial strength τ 0 is measured, which appears independent of radius, tip geometry, and elastic/plastic state of the substrate. This behaviour is demonstrated to apply to the behaviour of amorphous silica and single crystal quartz and significant friction anisotropy in sapphire is shown.

中文翻译：

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直接观察微米级单粗糙接触中的部分界面滑移

摘要 在由金刚石尖端和各种基底材料形成的微米级单粗糙接触中，在滑动之前观察到部分界面滑动。使用双轴纳米压痕仪，将增加的横向振荡载荷施加到在恒定法向载荷下缩进的触点。侧向载荷-位移曲线被提取，部分滑动表现为接触刚度随着振荡幅度的增加而稳定下降，在滑动过程中降至零。弹性和塑料接触都进行了检查，接触半径为 215-485 nm。测量界面强度 τ 0 ，其看起来与半径、尖端几何形状和基底的弹性/塑性状态无关。