Effect of nano-silica-particle additive on magneto-rheological behavior

This study investigates the effect nano-silica particle additive with different concentrations and sizes on magneto-rheological behavior of carbonyl iron particle suspensions from the tribological point of view. The lubrication states between particle–particle contacts and particle-plate contacts affected the magnetorheological behaviors. The silica particle additive leads to a larger friction coefficient at boundary lubrication conditions of the base carrier fluid which results in solid–solid contact states between the particles and plate and improves the yield stress. The normal stress and plate gap reflect that the nano-silica particles prevent the end of the ferromagnetic particle from sliding at the plate under high magnetic field, which enhance the friction effect between the particle and plate. The normalization methods based on the concept of tribology disclosed the influence of silica particle additives on the structural evolution of iron particles. It provides an effective guidance for the formulation design of MRF considering the effect of additives on the lubrication performance of the base carrier fluid.