Magnetorheology of carbonyl-iron Suspensions with submicron-sized filler

We added novel submicron-sized particles into carbonyl-iron (CI) suspension to improve the sedimentation problem. The added string-like graphite nano-fiber enhanced the resistance to sedimentation and improved flocculation stability without macroscopically noticeable change in the magnetorheological behaviors. This gap-filling submicron-sized particle between μm-sized CI spheres reduced the physical contact of CI particles, and reduced the caking behavior. These systems with and without additives were investigated and compared via a rotational rheometer by accurately controlling the magnetic field strengths.