A multi-beam intensity-based approach for lubricant film measurements in non-conformal contacts
A multi-beam intensity-based approach for lubricant film measurements in non-conformal contacts
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DOI：
10.1243/135065002760364822
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发表时间：
2002-01-01
影响因子：
2
通讯作者：
Wong, PL
中科院分区：
文献类型：
--
作者：
Guo, F;Wong, PL
弹性流体动力润滑（EHL）的研究经常利用光学干涉的现象，这是表现出当一个照明钢球与部分铬涂层的玻璃盘与已知折射率的润滑剂层结合接触。使用钢和铬表面可以检测具有与玻璃相似折射率的润滑剂。弹流润滑接触由两层极薄的铬涂层和润滑膜组成，并以玻璃盘和钢球为边界。本文报道了光学弹流润滑研究中常用的双光束干涉法在测量薄膜厚度时可能产生的较大误差。理论分析，其中包括考虑的影响，多光束干涉和光吸收的铬膜和钢表面。分析是用来设计一个多光束强度为基础的测试技术，已被验证为一个广泛的润滑油膜厚度测量在1 nm的分辨率，并提供了一个实际的最小可检测的膜厚度为1 nm薄。
Studies of elastohydrodynamic lubrication (EHL) frequently utilize the phenomenon of optical interference which is exhibited when an illuminated steel ball is in contact with a partially Cr-coated glass disc in conjunction with a lubricant layer of known refractive index. The use of the steel and chromium surfaces enables lubricants having similar refractive indices to glass to be examined. The EHL contact is composed of two microscopically thin layers: the Cr coating and the lubricant film, bounded by the glass disc and the steel ball. That the two-beam interference method frequently used in optical EHL research may induce significant errors in the measurement of film thickness is reported in this paper. A theoretical analysis which includes consideration of the effects of both multibeam interference and optical absorption within the Cr film and the steel surface is presented. The analysis is used to devise a multi-beam intensity-based test technique which has been validated for a wide range of lubricant film thickness measurements at a resolution of 1 nm and offers a practical minimum detectable film thickness as thin as 1 nm.