Characterization Of Magnetorheological Fluids Research Articles

Characterization of magneto-rheological fluid having elongated ferrous particles and its implementation in MR damper for three-wheeler passenger vehicle

In the present research work, Magneto-rheological (MR) fluid consisting of fiber-like elongated carbonyl ferrous particles as dispersed phase is characterized and the dynamic performance of the three-wheeled vehicle with an (MR) damper has been analyzed and discussed. Broadly, this paper has two segments, in the first segment, different proportions of MR fluid, that is, 10%, 15%, and 20% of volume fraction, are prepared and the corresponding rheological behaviors are studied experimentally at different current levels. In the second segment, the experimentally obtained properties of MR fluids are used to estimate the dynamic force of MR damper by using a non-parametric model of the flow-mode MR damper. Mathematical modeling of three-wheeler vehicle having MR damper model with proportional–integral–derivative (PID) control has been developed and the ride comfort and stability performances under poor road condition are studied. The result shows that the three-wheeler passenger vehicle equipped with an MR damper-based suspension system provides better ride comfort and stability with 27.6% reduction in bounce, 81.8% reduction in pitch, and 27.6% reduction in the roll motion of the body when compared to its passive suspension counterpart.

Characterization of Magnetorheological Fluid: A Study on Sedimentation and Redispersion

Herein, an induction method based setup for quantification of sedimentation behavior of magnetorheological fluids (MR fluids) consisting of 10% carbonyl iron powder in silicone oil is used. The effect of addition of Aerosil (stabilizer) on sedimentation is proposed with the help of “sedimentation index.” The proposed model of sedimentation index is compared with experimental measurement and is found to be in good agreement. In case of unavoidable event of settling, the important point is the ease of redispersion of sediment. This is directly evaluated with the help of a slider crank mechanism based setup which is proposed on the basis of the actual application. The quantification of redispersibility of the settled MR fluid is proposed using novel “redispersion index.” It is observed that increasing the concentration of Aerosil reduces the settling due to high off‐state viscosity, however, at the cost of redispersibility. In this study, the optimum trade‐off between the redispersibility and slow settling is obtained with 15% concentration of Aerosil in the MR fluid.

Synthesis and Characterization of Magnetorheological Fluids

Magnetorheological fluids (MRF) are mixture of ferromagnetic micron sized particles in silicon or hydraulic oil carrier fluid. By application of external varying strength magnetic field various physical properties of these fluids can be controlled and they becomes semi-solids depending on magnetic field strength application.MR fluids fulfill the desired performance requirements i.e. on application of magnetic field exhibits high shear and low initial viscosity, quick response , low hysteresis, low power consumption and temperature stability These special properties of MR fluids made them suitable for many type of industrial applications including machining. Hence fluids can be very effectively used in magnetorheological finishing process (MRF) which has unique feature of finishing truncated and complicated geometrical shapes and surfaces and capable of producing surface in nanometers. As surface finish is an important parameter in precision fits, product quality, and high-strength applications. The three dimensional surfaces finishing works such as different angled deep pockets or projections. Many industries have this type of i.e. mould & dies manufacturing, automobiles manufacturing, aerospace industry, semiconductor machining and optics machining etc. Such application leads to enhanced demand of nano-finishing of 3D surfaces without damaging surfaces/sub-surfaces. As due to change in properties because of change in composition the MR effect is also influenced. Therefore the composition of MR fluids is very important to achieve desired MR effect. The composition of magnetorheological fluids can be evaluated with the help of characterizations and desire MR fluid can be synthesized according to requirements of the process. This paper will explain in detail how we can synthesize and characterize the Magnetorheological fluids using state of the art equipments and can optimize their performance.

Influence of additives on the synthesis of carbonyl iron suspension on rheological and sedimentation properties of magnetorheological (MR) fluids

Magnetorheological (MR) fluid is one of the major constituent element in structural suspensions and damping characteristic in automobile applications. The major drawback is sedimentation in MR fluids, in the present study an attempt has been done to address the sedimentation issue. The synthesis and characterization of MR fluid in combination with clay and additives leads to improvement in sedimentation rate. The four different types of MR fluid were prepared in combination with clay, friction reducing agent and poly-alpha-olefin (PAO) oil naming as MRFp-1, 2, 3 and 4 as tabulated in table 1. The cost effective MRFp-3 shows better result compared to commercially available MR fluid with respect to off/on state shear stress, viscosity. It is also observed that in-house prepared MRFp-3 has better sedimentation than commercially available (LORD-132DG) up to 700 h.

Preparation and characterization of magnetorheological fluids by dispersion of carbonyl iron microparticles in PAO/1-octanol

This work reports an investigation into the effect of 1-octanol concentration in the formulation of concentrated polyalphaolefin-based magnetorheological fluids. Special emphasis is paid to the understanding of their kinetic stability and redispersibility characteristics in the ‘off-state’ (absence of magnetic field). Techniques employed involve light scattering, electroacoustics and rheometry, using a vane tool, to precisely determine the yield value. The results obtained show a minimum in the rheological material functions for 1-octanol concentrations within the range 0.5–5.0 wt%. This finding is tentatively explained in terms of the potential energy of interaction between the dispersed particles as a result of the formation of 1-octanol micelles in good agreement with Bombard and Dukhin (2014 Langmuir 30 4517–21).