Raman spectroscopy is applied for the non-destructive characterisation of the graphite which is used as solid lubricant in the friction material of semi-metallic brake pads in vehicles. The characteristics (intensity, position, width) of the main Raman bands assigned to vibrational modes of the graphitic honeycomb structure (G-band) and to defects (D-band) are proved useful probes of the quality and wear status of the graphite lubricant because they are sensitive to the structural disorder. It is found that wear of the graphite lubricant proceeds in two stages: transformation of crystalline to nanocrystalline graphite and subsequent amorphisation. Moreover, the intensity of the defect-related D′ peak is also used in order to obtain information about the nature of the defects.

中文翻译：

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拉曼光谱作为刹车片中石墨润滑剂磨损的评估工具

拉曼光谱用于非破坏性表征石墨，石墨用作车辆半金属刹车片摩擦材料中的固体润滑剂。分配给石墨蜂窝结构振动模式（G 带）和缺陷（D 带）的主要拉曼带的特性（强度、位置、宽度）被证明是石墨润滑剂质量和磨损状态的有用探针因为它们对结构紊乱很敏感。发现石墨润滑剂的磨损分两个阶段进行：结晶向纳米结晶石墨的转变和随后的非晶化。此外，还使用与缺陷相关的 D² 峰的强度来获取有关缺陷性质的信息。