MR Fluids With Nano-Sized Magnetic Particles

Abstract

Recently magnetorheological fluids with nanosized magnetic ferrite particles have become available. Their composition, rheological and magnetic properties are described. A comparison with conventional MR fluids based on micron-sized particles is given. The yield stress of nano-MR fluids can be increased by a moderate magnetic field (0,2 T) by 4000 Pa. It can be modulated by the magnetic field with a response time of less than 5 ms. Details are given on the long term thermal stability at 150 °C, on flow properties at elevated temperatures and at high shear rates. Design principles for MR fluid actuator design are outlined.

Vibration Control in Quarter-Car Model with Magnetorheological (MR) Dampers Using Bingham Model

“…Also thee main point of discussion that can be considered is that the MR fluids should be highly corrosion resistant asr it handles that most vulnerable component off any automobile. Consideringe this point, many different types of magnetic material haveebeen tested by the researchers depending on its emulsions withe different carrier fluids likee the magnetic material made off the polystyrene particles with the addition of the magnetite [3], thee nano-sized fferrite particles coated with a polymer [4], mesoscalee carbonyl iron ande nickel zinc ferrite ferrite [5], iron oxide forr magnetitei(Fe 3 O 4 ) nanoparticles [6]. The MR dampers from theirr inventions have beene used in many industrial applications.…”

“…The design parameters for Bingham Model are taken from [13,14]. Table 1 shows the values of different parameters for current values.…”

Developments in Vibration Control of Structures and Structural Components with Magnetorheological Fluids

“…Some of the carrier fluids are poly vinyl-n-butyl and naphthol-thickened kerosene 7 , silicone oil 8,9 , white and light grade mineral oils 10 , honge oil 5 , a combination of synthetic oil, water and organic liquids 11 . Silicone oil is widely selected as a carrier fluid, due to its superior qualities, such as good temperature stability, good heat transfer characteristics, oxidation resistance 12,13 , very low vapour pressure and high flash points. In other words, silicone oil experiences only a little change in physical properties over a wide temperature span (-40C to 204C), whereas the vegetable oils (bio-degradable) and their properties are temperature-sensitive 14 .…”

Synthesis and Characterisation of Nano Silver Particle-based Magnetorheological Fluids for Brakes

“…Mahesh 11 , et al prepared F-MRFs with varying volume percentage of ferrofluid nano particles and observed an enhancement in viscosity of MRFs with an increase in the number density of particles. Some researchers have prepared MR fluids as suspensions of polymer-coated nano size (diameter ~30 nm) ferrite particles 12 , iron-cobalt alloy particles 13 , and meso-scale carbonyl iron and nickel-zinc ferrites 6 , carbonyl iron and nano scale magnetic particle additives (Co-γ-Fe 2 O 3 , CrO 2 ) 14 . Phule and Ginder 6 reported the effectiveness in stabilization of nano-scale additives such as silica, fibrous carbon, and other polymers, forming a coating layer on the MR particles or making a thixotropic network.…”