Studies on Rheological Properties of Magneto-Rheological Fluid as a Function of Particle Size and Concentration

Abstract

AbstractMagneto-rheological (MR) Fluids are colloidal suspensions of magnetic particles in carrier fluid. MR Fluids shows unique rheological behavior on application of magnetic field. When magnetic field is applied these fluids change their viscosity drastically within milliseconds. The rheological behavior of fluid typically depends on the properties of magnetic particles like size, shape, density, saturation magnetization value and also on the concentration of particles in the fluid. In this study, we have investigated the influence of particle size and concentration of magnetic particles on the rheological properties of MR Fluid. MR Fluids were prepared by using two different sized carbonyl iron particles (i.e. 3–5 and 7–9 µm). Concentration of carbonyl iron particles were varied from (25 to 40) % by volume in silicon oil as carrier fluid. Experimental results show that on increasing the volume fraction of carbonyl iron particles shear stress and viscosity increases in both the cases. However, MR Fluid with large sized particles shows higher shear stress value and lower viscosity compared to the MR Fluid containing smaller sized particles.KeywordsMagneto-rheological fluidParticle shapeShear stressViscosity