The study of a sliding contact between a carbon-particle filled polymer and a noble (AgPd) alloy, lubricated with a silicone oil/PTFE grease, has shown the formation of a third body in the interface. The electrical application of the system has required an in-depth study of this third body to make sure that electrical conductivity was not endangered. Thanks to different chemical and electrical analyses, the third body, recognised as a tribofilm, can be described as a heterogeneous layer, composed mostly by transformed grease components and conductive wear particles. Coupling these observations and results from the literature, the formation mechanism is identified as tribopolymerisation by cross-linking of the silicone oil molecules, analogous to the well-known ‘gelation’ of silicone oils. The conditions for this phenomenon to occur in this system are discussed. Inclusion of wear particles from the conducting first bodies into the third body ensures low resistance: the tribofilm formed by this combination of mechanisms is a protective layer, which prevents polymer tracks from severe wear, without degrading electrical performance.

中文翻译：

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油摩擦聚合和磨料磨损在导电聚合物/贵金属电接触中形成保护性第三体的协同效应

碳颗粒填充聚合物和贵金属 (AgPd) 合金之间的滑动接触研究，用硅油/聚四氟乙烯润滑脂润滑，表明在界面中形成了第三体。该系统的电气应用需要对第三体进行深入研究，以确保导电性不会受到威胁。由于不同的化学和电气分析，第三个物体被认为是摩擦膜，可以被描述为一个异质层，主要由转化的油脂成分和导电磨损颗粒组成。将这些观察结果和文献结果结合起来，形成机制被确定为通过硅油分子交联的摩擦聚合，类似于众所周知的硅油“凝胶化”。讨论了在该系统中发生这种现象的条件。将第一导电体中的磨损颗粒包含在第三导电体中可确保低电阻：通过这种机制组合形成的摩擦膜是一个保护层，可防止聚合物轨迹严重磨损，同时不会降低电气性能。