Influence of temperature on magnetorheological fluid properties and damping performance

Abstract The magnetorheological (MR) system’s performance depends on the MR fluid’s temperature in operation. This study aims to evaluate the temperature effect of MR fluid on performance while the damper is working. Before synthesizing MR fluid, scanning electron microscopy, x-ray diffraction, and particle size analysis verifies for the synthesis of MR fluid in-house. Characterization of the MR fluid at different temperatures and magnetic fields was carried out. The Herschel–Bulkley model is used to analyse the nonlinearity in the fluid by incorporating the temperature effect. The range of critical parameters used to fabricate the MR damper is selected using the Technique for Order of Preference by Similarity to Ideal Solution performance score. The temperature of the MR fluid is measured using an embedded thermocouple while the damper is operating at different loading parameters. The results reveal that the fluid temperature rises significantly from atmospheric to 125.39 °C with decrease in damping force by 66.32% at higher loading parameters. The theoretical model predicts the increase in temperature similar to that of the experimental values with an average error of 10.24% in the on-state condition. Particle characterization after dynamic testing reveals particle morphology has not changed but the saturation magnetization of the particles reduced by 57% at higher temperatures (127 °C). It is observed through thermogravimetric analysis that, the life of the fluid is reduced by 0.25%, which is negligible after dynamic testing of the fluid for approximately 85000 cycles. Finally, to imitate the temperature effect on the particle, particles were heat-treated at 200 °C, 400 °C, and 600 °C, and through scanning electron microscope image it is confirmed that deterioration of the particle starts after 200°C, if the fluid is operated for a prolonged amount of time.