Dynamic and creep and recovery performance of Fe 3 O 4 nanoparticle and carbonyl iron microparticle water-based magnetorheological fluid

Abstract

This study investigates dynamic mechanical properties and creep and recovery behaviors of disc-shaped magnetic Fe₃O₄ nanoparticles with carbonyl iron (CI) flake-shaped microparticles in water-based MR fluid. The experimental study is performed using a parallel plate rheometer. Dynamic performance and creep and recovery behaviors help understand deformation mechanism for its practical applications in MR devices like seismic vibration control, active dampers, earthquake dampers, etc., under applied strain, and stress levels. The oscillatory experiment reveals a transition from viscoelastic-to-viscous behavior at the critical strain of 0.1%. The storage modulus $\left(G^{\prime }\right)$ of CI/Fe₃O₄ MR fluid showed a stable plateau region over the small strain area and storage modulus $\left(G^{\prime }\right)$ independent of strain amplitude. The frequency experiment demonstrated that storage moduli $\left(G^{\prime }\right)$ exhibit elastic response and stable plateau region over the complete external frequency range, suggesting the distinguished solid-like behavior of the MR fluid. Creep and recovery experiments showed that fluid acts as a linear viscoelastic material at lower stress levels. As the stress levels increase, the contribution of retardation strain and viscous strain decreases, and it acts like nonlinear viscoelastic material. In summary, this work is expected to obtain MR fluid results for application in MR devices under applied strain, frequencies, and constant stress levels.