Morphological Influence of Molybdenum Disulfide on the Tribological Properties of Rapeseed Oil

The morphological influence of molybdenum disulfide (MoS2) on the tribological properties of rapeseed oil (RO) was investigated. MoS2 nano-vesicles improved the tribological properties of RO, especially the wear resistance. However, nano-platelets and micro-platelets weakened the wear resistance because of their bad dispersibility in RO. Positive synergistic lubrication was observed between nano-vesicles and nano-platelets, but not between nano-vesicles and micro-platelets or nano-platelets and micro-platelets. Abrasive plowing is the main wear manner for the steel balls lubricated by RO or ROs with platelet-like MoS2. However, chemical corrosive wear occurred on the friction surface as lubricated by RO with nano-vesicles. The chemical corrosive wear confirmed the entering of MoS2 nano-particles to the contact area for lubrication. This lubrication of nano-vesicles was ascribed to their spherical structure and good dispersibility in RO. The nano-vesicles did not influence the stability of RO and assembled beside furrows to alleviate the wear. Thus, potential applications of MoS2 nano-vesicles in vegetable oils were revealed.