Magnetic carbonyl iron nanoparticle based magnetorheological suspension and its characteristics

Magnetic nano-sized carbonyl iron (CI) particle was prepared and adopted as an additive for micron-sized CI based magnetorheological (MR) fluid, in which the magnetic nanoparticle was fabricated via decomposition of pentacarbonyl iron (Fe(CO)(5)). Magnetic property and morphology of the nanoparticle were confirmed via vibration sample magnetometer (VSM) and transmission electron microscopy (TEM), respectively. MR fluids, consisting of micron-sized CI and carrier fluid, were investigated under different external magnetic field strengths via a rotational rheometer. Their flow behaviors at a steady shear mode were examined with and without a nano-sized magnetic additive under magnetic field strength. The MR fluid with magnetic CI nanoparticle added demonstrated slightly higher yield behaviors, suggesting that micron-sized CI and magnetic CI nanoparticle particle were being oriented in magnetic field direction under applied magnetic field and with strengthened structure. (C) 2009 Elsevier B.V. All rights reserved.