Synthesis of magnetorheological fluids and investigation of their rheological properties

Magnetorheological fluids (MR) are the fluids that can be controlled by magnetic field-effect flow properties containing magnetic particles with magnetic properties scattered in a suitable carrier fluid. These fluids have become very popular in recent years due to the advantages resulting from quick and reversible variation of their rheological properties with magnetic field. As a result of the increase in the studies on MR fluids, different usage areas have emerged in which MR fluids are involved. These fluids are used in many areas such as automobile industry, civil engineering, space and aerospace because of the damping properties of MR fluids due to external factors such as vibration and impact . In addition, some studies show that MR fluids can be used in medical and biomedical fields. In this study, it is aimed to examine the rheological behavior of various MR fluids that are prepared with apricot kernel oil. For this reason, magnetic particle size, magnetic particle concentration and magnetic field strength were chosen as the working parameters and rheological behaviors of the synthesized fluids were examined under various magnetic field intensities. Two different MR fluids were prepared by using commercially available laser printer toner powder and Fe3O4 particles that were synthesized in the laboratory. Rheological behaviors of 6 samples which were prepared by using particles having various concentrations (20 %, 30 % and 40 %) were examined under various magnetic field intensities. The results obtained showed that the increase in magnetic particle size, magnetic particle concentration and applied magnetic field strength increased the viscosity and shear stres values of the MR fluids. On the otherhand, sedimentation of particles of MR fuids was alsoin vestigated. As a result, it was determined that as the magnetic particle size and concentrationin creased, the sedimentation ratioin creased, and as the magnetic field intensity, particle size and concentrationin creased, the yield stress value of MR sample salsoin creased.