Kałużny Jarosław, Kulczycki Andrzej, Dzięgielewski Wojciech, Piasecki Adam, Gapiński Bartosz, Mendak Michał, Runka Tomasz, Łukawski Damian, Stepanenko Oleksandr, Merkisz Jerzy, Kempa Krzysztof
Faculty of Civil and Transport Engineering, Poznan University of Technology, 60-965 Poznań, Poland.
Air Force Institute of Technology, 01-494 Warsaw, Poland.
Nanomaterials (Basel). 2020 Jul 8;10(7):1330. doi: 10.3390/nano10071330.
Experimental studies reveal that the simultaneous addition of zinc dialkyl dithiophosphates (ZDDPs) and multi-wall carbon nanotubes (MWCNTs) to a poly-alpha-olefin base oil strongly reduces wear. In this paper, it is shown that MWCNTs promote the formation of an anti-wear (AW) layer on the metal surface that is much thicker than what ZDDPs can create as a sole additive. More importantly, the nanotubes' action is indirect, i.e., MWCNTs neither mechanically nor structurally strengthen the AW film. A new mechanism for this effect is also proposed, which is supported by detailed tribometer results, friction track 3D-topography measurements, electron diffraction spectroscopy (EDS), and Raman spectroscopy. In this mechanism, MWCNTs mediate the transfer of both thermal and electric energy released on the metal surface in the friction process. As a result, this energy penetrates more deeply into the oil volume, thus extending the spatial range of tribochemical reactions involving ZDDPs.
实验研究表明,将二烷基二硫代磷酸锌(ZDDPs)和多壁碳纳米管(MWCNTs)同时添加到聚α-烯烃基础油中可显著降低磨损。本文表明,MWCNTs促进了金属表面抗磨(AW)层的形成,该抗磨层比ZDDPs作为单一添加剂时所形成的抗磨层要厚得多。更重要的是,纳米管的作用是间接的,即MWCNTs既不会在机械上也不会在结构上强化抗磨膜。本文还提出了一种对此效应的新机制,详细的摩擦磨损试验机结果、摩擦轨迹三维形貌测量、电子衍射光谱(EDS)和拉曼光谱都支持这一机制。在该机制中,MWCNTs介导了摩擦过程中金属表面释放的热能和电能的传递。结果,这种能量更深入地渗透到油相中,从而扩展了涉及ZDDPs的摩擦化学反应的空间范围。