Study on sedimentation stability of magnetorheological fluids based on different lubricant formulations

Magnetorheological Fluids (MRFs) is rapidly emerging as a type of new fluid intelligence material that is controllable and low-energy consuming with high output and fast response. It has already received widespread attention from many international scholars. In this paper, the orthogonal test of MRFs configuration with six different types of lubricating additives (oleic acid, hydrogenated castor oil, teflon, boron nitride, molybdenum disulfide, graphite) is conducted to study the wettability, zero-field viscosity and yield stress of MRFs under different solid lubricants. According to the size of contact angle, the ability of anti-sedimentation stability of MRFs under different lubricants is compared. The zero-field viscosity of MRFs is tested by viscometer, and the strength of viscosity under the zero-field condition is compared. The yield stress is measured by a self-made yield stress device, and then the sedimentation stability characteristics of MRFs are analyzed. Finally, through the analysis and evaluation of experimental data, it is concluded that molybdenum disulfide as a lubricating additive can effectively improve the anti-sedimentation stability of MRFs, and the general rules of lubricating additives used in MRFs formulations with excellent performance are summarized.