Tribological characterization of eco-friendly bio-based mahua and flaxseed oil through nanoparticles

In this research study, the rheological and tribological properties of mahua oil (MO) and flaxseed oil (FO) were investigated by incorporating the TiO2, ZrO2, graphite, and MoS2 nanoparticles (NPs) as lubricant additives. The nanolubricants were synthesized by dispersing these NPs in MO and FO with varying concentrations from 0.25 to 1.25 wt.% through ultrasonicator and magnetic stirrer. The rheological tests were performed on a cone and plate rheometer, and the tribological test was performed on four-ball tester. The rheological test results depict that the nanolubricants exhibit Newtonian behavior at 40 degrees C and 100 degrees C. The tribological test results confirm that the average wear scar diameter (AWSD) of MO is much lower than FO and the maximum reduction in AWSD was 34.4%. TiO2 and graphite NPs exhibit excellent anti-wear properties in MO, and the maximum reduction in AWSD was 6.5% and 10.14% at an optimum concentration of NPs 0.75wt.%. ZrO2 and MoS2 NPs showed negative effects in MO, and maximum AWSD was observed at 0.75 wt.% and 0.5 wt.%, respectively. TiO2, ZrO2, and MoS2 NPs perform superior anti-wear properties in FO, and the maximum reduction in AWSD was 30.2%, 11.7%, and 15%, respectively. The optimum concentration of TiO2, ZrO2, and MoS2 NPs in FO was 0.25 wt.%, 0.75 wt.%, and 1 wt.%, respectively. The graphite NPs exhibit a lower reduction in wear in FO, and maximum reduction in AWSD was observed 4.5% at a concentration of 0.5wt.%. Among these NPs, graphite NPs could be considered the best suitable anti-wear nano additives for MO and TiO2 NPs for FO.