English

Abstract

Magnetorheological (MR) fluids can be used as brake friction materials (1-6). During braking, kinetic energy of machines gets converted into heat and shear thinning of MR fluid due to increase in temperature occurs which in turn reduces the braking effect. To lessen the effect of heat generation on MR fluids due to heat, synthesis of magnetorheological fluid using nano-copper-powder has been proposed. To explore the feasibility of incorporating copper powder, four carbonyl iron (CI) powder based MR fluids (without any copper powder, with 0.25% weight, 0.5% weight and 0.75% weight copper powder) have been synthesized. Yield stress of all four MR fluids have been estimated using magnetorheometer. A flywheel based MR brake experimental setup has been developed to analyze the performance of synthesized MR fluids. To increase the braking torque of MR brake, compression mode along with the shear mode has been introduced. The comparison of the braking torque in shear and compression modes has been presented. T type thermocouples have been used to measure the temperature distribution of the fabricated MR brake. Results of braking torque and corresponding temperature distribution are presented.