Enchancment in viscoelastic properties of flake-shaped iron based magnetorheological fluid using ferrofluid

We have investigated the effect of ferrofluid incorporated (5-20% v/v) flake-shaped iron particles in silicion oil based magnetorheological fluid (MR fluid). The fluids physical properties like crystalline phase, shape size distribution and magnetization of both the fluids were studied individually. Thereafter, magnetic stimuli-response of ferrofluid doped MR fluid on rheological properties was determined in static and dynamic modes. The observed enhancement in yield stress due to addition of magnetic nanoparticles is correlated using universal yield stress scaling equation with magnetic field strength. Subsequently, cylindrical measurement technique is used to investigate fluid stability over time. Further, the relative viscosity (eta/eta(infinity)) -vs- Mason number (Mn) shows scaling (Mn = 10(-2)), at higher magnetic field confirming negligible thermal and colloidal forces. The oscillatory strain sweep tests reveals a cross-over from viscoelastic-to-viscous behavior of suspension at critical strain value y = 0.1. The increase in dynamic efficiency at is due to the reduction in sliding friction.