Thermal and Tribological Performance of Graphite Flake-Based Magnetorheological Fluid Under Shear Mode Clutch

Abstract In this research work, graphite flake has been used as an additive in magnetorheological (MR) fluid to improve its thermal and tribological performance. MR fluids with varying amounts of graphite flakes (0.5, 1, 2, 3, 4, and 5 wt%) are prepared to show effective thermal and tribological performance. A test rig is developed with a DC motor, torque sensor, and MR clutch operated in a shear mode to test the torque transmission. Results show the lubrication effects of graphite flakes in the MR fluid. Torque transmission is improved in on-state and off-state using graphite flakes-based MR fluid as compared with conventional MR fluid. Heating of the MR clutch is also reduced with the graphite flakes-based MR fluid. Wear marks and damages are decreased significantly with the increased amount of graphite flakes as found in surface roughness tests. Scanning electron microscopy and energy-dispersive spectroscopy are used to characterize the worn surfaces. This research provides information about the effectiveness of graphite flakes in the MR clutch to improve the device’s performance.