A Novel Preparation Process for Magnetorheological Fluid with High Sedimentation Stability

Abstract

We report the preparation of a high-performance magnetorheological (MR) fluid by using silane coupling agent and bentonite as additives at appropriate contents determined by a series of experiments. We also adopted a new preparation process that was optimized through an orthogonal experimental design. The effects of process parameters on the sedimentation stability of the MR fluid were determined. Sedimentation ratio, apparent viscosity, and yield stress were measured to evaluate the performance of the MR fluid prepared by the optimized process. Results indicated that the MR fluid exhibited enhanced sedimentation stability when the silane coupling agent and bentonite mass fractions were 2.88% and 3.60%, respectively. Moreover, the effect of the second stirring process on sedimentation stability was found to be more important than the first. The optimal preparation parameters determined for the high-performance MR fluid are as follows: first and second stirring temperature of 20°C, first stirring time of 5 min, second stirring time of 5 h, and first and second stirring rotation speed of 2000 rpm.