Augmenting the lubrication performance of nano-oils through synergistic co-functioning of nanoparticles

• Published in: Tribology international 2023-04, Vol.182, p.108332, Article 108332
• Main Authors: Saini, Vinay, Bijwe, Jayashree, Seth, Sarita, Ramakumar, SSV
• Format: Article
• Language: English
• Subjects: Anti-wear (AW); Nanoparticles; Polytetrafluoroethylene; Synergism; Weld load
• ISSN: 0301-679X; 1879-2464
• DOI: 10.1016/j.triboint.2023.108332

The lubricant industries are desperate for novel lubricants that can withstand extreme pressure (EP) conditions apart from having excellent antiwear (AW) and anti-friction (AF) properties. This work aims to augment the overall lubrication potential of Polytetrafluoroethylene (PTFE) based nano-oils (oval-shaped, 200 nm) by incorporating nanoparticles (NPs) of various types and shapes (graphite 55 nm spherical, lamellar multilayer graphene, lamellar talc (50–100 nm), Titanium 70 nm spherical, and MoDTC 20 nm spherical. Hybrid nano-oils comprising PTFE NPs in combination with selected NPs in a 3:1 ratio were formulated and explored for possible tribo-synergism for AW, AF, and EP capabilities. All hybrid oils proved superior to the solo oils, indicating their synergistic capability. Overall, formulations with MoDTC (commercial friction modifier) yielded the highest tribo-synergism for all parameters, mainly owing to the formation of a mechanically mixed tribo-layer of PTFE/MoS2 at interfacial contacts at high loads. At lower loads, MoDTC quickly formed a low-shear, thin MoS2 tribo-film, which boosted the AW performance of PTFE NPs. The inclusion of just 1 % of MoDTC showed the highest synergistic benefits with PTFE NPs, enhancing weld loads from 560 to 700 kg with a nearly 25 % increment in performance. The tribo-properties of oils can be tuned by incorporating a unique combination of NPs as additives due to cooperativity in lubrication mechanisms. [Display omitted]