Flow behaviour of lubricants largely depends on their rheological properties which in turn strongly influence their lubrication capabilities and ultimately the machine life. Modern chemistry plays a great role in the synthesis of nano-additives that help in enhancing the rheological and tribological properties of the lubricants. In the present study, the rheological and tribological studies of MoS$_2$ nanofluids are presented in order to determine their flow behaviour and lubrication capabilities. For studying the effect of MoS$_2$ nanoparticles on the flow behaviour and lubrication capabilities of lubricants, two commercially available blended synthetic engine oils of SAE grades 5W-40 were selected. MoS$_2$ nanoparticles were synthesized by hydrothermal methods. Surface modification of the synthesized MoS$_2$ nanoparticles was performedbefore blending them with the base lubricants in 0.1, 0.15 and 0.2% concentrations. Standard ASTM and IS procedures were used to determine physicochemical properties and tribo-performance behaviour of oils, respectively. The rheological parameters of MoS$_2$ nanofluids were determined using a rheometer. The study reveals that tested MoS$_2$ nanofluids behavedas non-Newtonian lubricants with shear thinning behaviour at all tested temperatures and exhibited viscoelastic behaviour at small-shear rates. As a result of this anti-wear property showed a significant enhancement up to 20% for 0.2% MoS$_2$ indicating better anti-wear properties of MoS$_2$ nanofluids. However, a marginal reduction in friction for the tuning of 4% observed for 0.2 wt% of MoS$_2$ nanoparticles in the tested lubricants indicates that finished products have little scope to improve anti-friction properties under the influence of the already present additives.
Volume 44, 2021
Continuous Article Publishing mode
Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
Chemical Sciences 2020
Prof. Surajit Dhara — School of Physics, University of Hyderabad, Hyderabad
Physical Sciences 2020
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