Simultaneous Thermo-Magnetorheological Response of Magnetorheological Fluids: Effect of Concentration and Composition

The rheological behavior of magnetorheological fluids (MRFs) is greatly influenced by many key parameters such as concentration, composition, temperature, and magnetic field. As magnetic particles are dispersed in a non-magnetic liquid, MRFs exhibit an increase in viscosity with increasing magnetic fields due to the formation of chain-like structures. However, this viscosity change has often been studied as a function of any one or two of the key parameters. Herein, we studied the simultaneous effect of temperature, magnetic field, concentration of dispersed phase, and MRF composition on the viscosity of MRFs. Understanding the simultaneous effect of tunable parameters such as temperature and magnetic field allows for optimization of MRF performance and enhanced viscosity in commercial applications. Rheological experiments were performed on MRFs over a wide range of temperatures (15–65 °C) under magnetic fields between 0.1 and 1 T. The thermo-magnetorheological response was also studied with varying magnetic particle concentration (1 vol%–25 vol%) and MRF composition (both dispersed phase and carrier liquid). The results demonstrated a strong influence of magnetic particle composition and concentration on the MRF viscosity along with temperature while the carrier liquid composition had relatively negligible influence.