Impact of corrosion process of carbonyl iron particles on magnetorheological behavior of their suspensions

Abstract

The study investigates an influence of carbonyl iron (CI) particles’ corrosion on magnetorheological performance of their silicone-oil suspensions. Carbonyl iron particles were oxidized thermally at 500 °C in the air or chemically in 0.05 HCl solution and the as-treated particles were subsequently used as a dispersed phase in magnetorheological suspensions. Corrosive layer on surface of oxidized particles was investigated using X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). Obtained rheological data was treated with Robertson–Stiff (R–S) model to determine yield stress values and in order to find the yield stress values of prepared magnetorheological (MR) suspensions at saturation level a mathematical model was used. The suspensions based on oxidized particles showed lower values of the yield stress, which was significantly manifested at higher magnetic field intensities due to lower saturation magnetization of the particles. © 2018 The Korean Society of Industrial and Engineering Chemistry