磁気粘性流体の作製法の検討及び流動特性の評価

抄録

Magnetorheological (MR) fluids are smart fluids which have a property that the viscosity rapidly increases by applying a magnetic field, and they have already been put to practical use in automobile dampers and seismic isolation devices. MR fluid is composed of iron particles, a carrier fluid such as silicone oil, and a surfactant for improving the dispersibility of the particles. Depending on the combination and content of these materials, the fluidity of the MR fluid is changed. Particularly, the combination of the carrier fluid and the surfactant greatly affects the fluidity. In this study, preparation of MR fluid was considered, and the rheological properties of the MR fluid under no magnetic field condition was evaluated. The results showed that: (1) The fluidity of the MR fluid was remarkably improved when a surfactant having a low HLB value was used. (2) The viscosity and the yield shear stress increased with the increasing particle volume fraction. (3) The surfactant raised the viscosity but reduced the yield shear stress of the MR fluid under no magnetic field condition.