Performance of silicon oil-based Magneto-Rheological fluids used for MR dampers: an experimental approach

The aim of this work was preparation of the model Magneto Rheological (MR) fluids to be used under the effect of an applied magnetic field operated under very low power requirement for the purpose of vibration reduction in automotive damper. Magneto-Rheological fluids are non-Newtonian fluids, which consist of magnetic particles scattered in a base liquid – a matter that can change their characteristics when applying the magnetic field. From the previous researches, Magneto-Rheological fluids have different properties according to the preparation accuracy, ingredients, particle size and shape, type of carrier fluids and stabilizer. Also, the response of Magneto-Rheological fluids to the magnetic flux varied. : A specimen of MR fluid is prepared using four different dynamic viscosities base fluids: Silicone oil JETTA (50mpa.s, 100mpa.s, 150mpa.s and 200mpa.s) are mixed with high purity spherical shape particles of Carbonyl Iron (CI). ABRO liquid white lithium grease is added to the specimen, and its effect is determined. The presence of additives has no effect on the magnetic behavior; but rather increases dynamic viscosity, especially in the presence of the external magnetic field, which is considered as a stabilizing factor. Adding the white lithium grease as a stabilizer delays the sedimentation of the prepared sample by 1023%. The lowest sample in sedimentation rate has the highest viscosity, which satisfies 2.7% in 24 hours, but it shows a negative effect on the magneto-rheological properties, which leads to unstable viscosity readings due to MR fluid agglutination. Working temperature is a critical parameter that can affect the behavior of MR fluid; the viscosity of MR fluid under the effect of magnetic field is inversely proportional to the working temperature. Sample DELTA is the most promising for the application in automotive dampers which are used to decrease vehicle vibration.