Investigation of Anti-Friction Properties of MoS2 and SiO2 Nanolubricants Based on the Friction Pairs of Inconel 718 Superalloy and YG6 Carbide

In order to improve the anti-friction property of common mineral oil and develop a high-performance lubricant, MoS2 and SiO2 nano-additives were individually dispersed into the 350SN mineral oil at various weight percentages to prepare nanolubricants. Then, the viscosity, wettability, and tribological properties of the nanolubricants were measured and analyzed with a rotary viscometer, a contact angle measuring instrument, and a friction tester. Finally, the action mechanism of two nano-additives was explained based on the energy spectrum test results of the abrasion surface. The results show that MoS2 and SiO2 nano-additives could improve the viscosity of the base fluid and change its wettability, giving nanolubricants better anti-friction performance than the base fluid. Due to the difference in physical properties, SiO2 and MoS2 nanolubricants presented different friction reduction rules with the increase in nano-additive percentage. Under experimental conditions, SiO2 nanolubricants showed better anti-friction effects than MoS2 nanolubricants. When the SiO2 percentage was 10 wt% and 15 wt%, the maximum friction coefficient was reduced to 0.06, which was about 1/3 of that with the base fluid. In this case, the abrasion surface quality was significantly improved, and the abrasion trace size was about half that of the base fluid. The energy spectrum test results show that the action mechanism of the MoS2 nano-additive is the adsorption film effect and mending effect of nanoparticles, while the main action mechanism of the SiO2 nano-additive should be the polishing effect and rolling effect of nanoparticles.