(552h) Evaluating the Impact of Carbon Microspheres on the Stribeck Curve of Aqueous Lubricant

Previous studies have demonstrated that carbon microspheres can be used as additives to enhance the performance of lubricants due to their ability to function as ball bearings that help to reduce friction and mechanical wear in moving parts. This work aims to investigate the impact that carbon microspheres have on the respective lubrication regimes of the Stribeck curve – boundary, mixed and hydrodynamic. 60 wt% glycerol aqueous mixture is used as the base lubricant and carbon particles (with a mean size of 200 nm) are dispersed in varying amounts to obtain concentrations of 1 - 4mg/ml respectively. The tribological performance of the composite micro-lubricant will be studied on a pin-on-disk tribotester with a silicon wafer as the disk and an uncoated glass lens as the probe. Stribeck curve analysis of the results will be conducted to determine how the plot responds to varying concentrations of micro-lubricant. Wear track analysis will also be carried out using SEM and AFM to confirm the mechanism of lubrication. Since the boundary regime experiences the most asperity contact between the friction pair, it is expected that the particles will play the greatest role in this regime and provide the highest reduction in coefficient of friction than other regimes. This fundamental study will provide further insight into the role of microparticles in lubrication.