Innovative doped flaky FeSiCr interface synergy for developing bidisperse magnetorheological fluids with super‐performance

Abstract The key application performances of magnetorheological fluids (MRFs), such as shear yield strength, sedimentation stability, zero‐field viscosity, redispersibility, and durability, exhibit trade‐off relationships. However, the traditional methods that change a single parameter, such as the special morphology, chemical composition, or interface properties, produce limited improvements in the comprehensive performance of MRFs. A multidirectional synergistic modification that combines particle composition, interface, morphology, and multiscale particle systems will be more conducive to the improvement of the comprehensive performance of MRFs. In this work, we develop a transformative flaky FeSiCr MRF, which exhibits high magnetic permeability, low remanence, and excellent wear resistance, via solvent‐assisted ball‐milling. The results demonstrate that, when compared with commercial MRFs, the shear yield strength, sedimentation stability, redispersibility, and durability of these bidisperse MRFs ultimately improve over the entire magnetic‐field range. The specific mechanism of the enhancement in the comprehensive performance is clarified based on Brownian‐dynamics simulations, interface synergy effect, and performance characterization of the particles‐chain‐like structure. The combination of superior comprehensive performance and simple manufacturing process further enhances the engineering applicability of the bidisperse‐particle‐system MRF.