A trivalent ferrite ferrofluid compound’s rheological response to angular frequency, magnetic induction and shear induction of chain clusters

Abstract

Abstract At low and high temperatures in the presence and absence of magnetic fields, the effects of shear rate, angular frequency, and shear strain on the rheological characteristics of zinc ferrite ferrofluid is investigated. Chemical co-precipitation was used to create a zinc ferrite ferrofluid that was then coated with oleic acid to improve the stability of the fluid’s particles and avoid particle agglomeration. We looked at the rheological characteristics caused by the induced magnetic field, such as the shear stress, complex viscosity, storage modulus, loss modulus, relaxation modulus, viscous torque, damping factor, and figure of merit. From the analysis of time dependent relaxation modulus, a steady-state rheological system is formed at time interval beyond 50 s. As the shear and complex viscosities increase with an increase in magnetic field and a decrease in temperature, obstruction to fluid flow is produced. When a rheological system operates at low angular frequency and high shear rate, high shear stress is loaded; when it operates at high angular frequency and low shear rate, low shear stress is loaded. In the absence of magnetic field, a low viscosity 0.425 Pa.s and shear force 46 Pa were formed, while high viscosity 8.140 Pas and shear stress 168 Pa were formed when magnetic field 1.000 Tesla was applied. The oscillatory mode test demonstrates a change in structure from solid to liquid due to the establishment of a crossover point between shear strain 55 and 64%, supporting the solid–liquid phase transition behavior. The damping analysis demonstrates that the system is in fact excessively dampened, and it may now be utilized to reduce vibrations in a system. The system is really overdamped showing a maximum damping factor 2.08, according to the damping study, and can therefore be used to reduce vibrations in other systems. The fluid exhibits non-Newtonian shear-thinning behavior as shear rates increase. A high viscous torque is created at low shear strain and high angular frequency, which leads to the creation of a strong rotating magnetic field.