Effect of Halloysite Clay on Magnetic Carbonyl Iron-Based Magnetorheological Fluid

Soft magnetic carbonyl iron (CI)-based magnetorheological (MR) fluids with different loadings of halloysite nanoclay were prepared, in which the MR fluid is a complex colloidal suspension consisting of magnetic particles dispersed in a liquid, showing its rapid, reversible, and tunable change between a liquid-like and solid-like state with an applied external magnetic field. The MR characteristics were measured via rotational tests, in which the flow curves exhibited a non-Newtonian behavior for all investigated samples under applied magnetic fields. Flow curves showed not only the dynamic yield stress change measured as a function of magnetic field strength using a power law fit, but also the existence of a solid-like character. Sedimentation of the MR fluid with and without an additive was also examined.