| 초록 |
MR properties were investigated for suspensions of CI, bulk and flake shaped sendust particles under the external magnetic field. The surface morphology was observed by SEM. The magnetic properties of each sample were investigated by using a VSM and a rotational rheometer. the flake shaped sendust showed exceptional movement which is a rapid ascent of the magnetic moment and yield stress at low magnetic field. At high magnetic field, all suspension displayed similar MR behavior. And the master curves describing the apparent viscosity was obtained by appropriate adjustment, which showed a combination of dimensional analysis and flow curve analysis with yield stresses obtained from the prediction models, Bingham and Seo-Seo model. Finally, the sedimentation stability was tested using a Turbiscan apparatus. The MR suspension with the flake shaped sendust exhibited remarkable improvement of stability compared to those of CI and bulk shaped sendut due to the drag coefficient. |
