The use of highly viscous grease as a medium in magnetorheological grease (MRG) provides the benefit of avoiding sedimentation from occurring. However, it limits the expansion of yield stress in the on-state condition, thus reducing the application performance during operation. Therefore, in this study, the improvement in the rheological properties of MRG was investigated through the introduction of graphite as an additive. MRG with 10 wt % graphite (GMRG) was fabricated, and its properties were compared to a reference MRG sample. The microstructure of GMRG was characterized using an environmental scanning electron microscope (ESEM). The rheological properties of both samples, including apparent viscosity, yield stress, and viscoelasticity, were examined using a shear rheometer in rotational and oscillatory modes. The results demonstrated a slight increase in the apparent viscosity in GMRG and a significant improvement in yield stress by 38.8% at 3 A with growth about 32.7% higher compared to MRG from 0 to 3 A. An expansion of the linear viscoelastic region (LVE) from 0.01% to 0.1% was observed for the GMRG, credited to the domination of the elastic properties on the sample. These obtained results were confirmed based on ESEM, which described the contribution of graphite to constructing a more stable chain structure in the GMRG. In conclusion, the findings highlight the influence of the addition of graphite on improving the rheological properties of MRG. Hence, the addition of graphite in MRG shows the potential to be applied in many applications in the near future.

The utilization of high viscous grease as a medium in Magnetorheological grease (MRG) has benefits in avoiding the sedimentation from occurred, however, it limits the expansion of yield stress in on-state condition thus reduced the application performance upon operation. Therefore, in present study, improvement of the rheological properties of MRG has been investigated by introduction of graphite as an additive. MRG with 10 wt% of graphite (GMRG) was fabricated and the analysis of the properties was compared to the reference sample, MRG. The microstructure of GMRG was characterized through Environmental Scanning Electron Microscope, (ESEM). While, the rheological properties including apparent viscosity, yield stress and viscoelastic properties for both samples were examined using shear rheometer under rotational and oscillatory mode. The results demonstrated slightly increment of apparent viscosity in GMRG and shows a significant improvement in term of yield stress by 38.8% at 3A with growth about 32.7% higher compared to MRG from 0A to 3A. Also, an expansion of linear viscoelastic region (LVE) from 0.01 to 0.1% was observed in the GMRG credited to the domination of elastic properties on the sample. These results obtained was confirmed based on ESEM that displayed the contribution of graphite towards constructing more stable chain structure in GMRG. In conclusion, this study highlights the influence of graphite towards improving the rheological properties of MRG. Hence, addition of graphite in MRG is a great potential to be applied in many applications in near future.