Effect of Oleic Acid Lubricating Performance on Yield Behavior of Magnetorheological Fluid

The effect of different concentrations of oleic acid additive on the yield behavior of a magnetorheological fluid (MRF) was investigated from the perspective of tribology. Different concentrations of oleic acid (OA) influence the magnetorheological effect by altering the lubricating properties of the base carrier liquid. Good lubricity of the carrier fluids led to lower shear stresses. The friction between the particles and that between the particles and plates were a part of the shear stress. The structural evolution was promoted by both lubrication and shearing. The shearing thinning of the MRF was delayed under good lubricity, and the particles were easier to roll. The friction forces, along with Brownian forces, Stokes forces, and magnetic attraction, affect the structural evolution of MRF. This study provides a new theory for the formulation design of magnetorheological fluids, reducing design costs and improving production efficiency.