In the current study, surface temperature in sliding contacts was in situ measured by Raman spectroscopy. The contact area comprised a stationary sapphire hemisphere and a rotating carbon steel disk. The surface temperature was estimated from the Raman spectrum of sapphire. Three estimation methods of temperature were compared, which were obtained from the peak shift, full width at half maximum (FWHM), and intensity ratio of Stokes/anti-Stokes scattering. The estimated temperature from the peak shift exhibited the least fluctuations among the three methods. However, the peak shift varied with stress and temperature. The estimated temperature from the FWHM was highly accurate, although the fluctuation was greater than that from the peak shift. The estimated temperature from the intensity ratio of Stokes/anti-Stokes scattering was unaffected by pressure and crystallinity, although this estimated temperature exhibited a significant fluctuation because the signal-to-noise ratio of the anti-Stokes scattering was small. This in situ measurement technique using Raman spectroscopy can simultaneously acquire the temperature and chemical state of the sliding surface. Namely, the temperature of a tribofilm and the temperature during scuffing can be measured directly and the mechanism can be analyzed effectively.

Graphical Abstract

中文翻译：

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拉曼光谱法原位测量滑动表面温度

在当前的研究中，滑动触点的表面温度为拉曼光谱法原位测量。接触区域包括一个固定的蓝宝石半球和一个旋转的碳钢盘。表面温度是根据蓝宝石的拉曼光谱估计的。比较了三种估计温度的方法，这些方法是从峰位移，半峰全宽（FWHM）和斯托克斯/反斯托克斯散射的强度比得出的。根据峰位移估算的温度在三种方法中显示的波动最小。但是，峰位移随应力和温度而变化。从FWHM估算的温度是非常准确的，尽管波动大于从峰值偏移获得的波动。根据斯托克斯/反斯托克斯散射的强度比估算的温度不受压力和结晶度的影响，尽管该估计温度显示出明显的波动，因为抗斯托克斯散射的信噪比很小。这种使用拉曼光谱的原位测量技术可以同时获取滑动表面的温度和化学状态。即，可以直接测量摩擦膜的温度和刮擦期间的温度，并且可以有效地分析机理。

图形概要