Nano-MRF: A Material for Damping Application

Abstract

A magnetorheological fluid (MR), a suspension of micron-sized magnetic particles in a carrier fluid, has vast applications in the field of vibration dampers, seismic vibration dampers, shock absorbers, clutches, break system, vehicle suspensions, seat suspensions, Robotics, design of buildings and bridges etc. The biggest issue in MR fluid is the settling of particles under gravity. To overcome this, one of the approaches is to mix micron size particles in a magnetic fluid (MF) known as Nano-MRF. In the present paper, we report a technique to synthesis Nano-MRF suspension having high stability under gravitation as well as magnetic field. X-ray diffraction (XRD) and dynamic light scattering are used to characterize the solid/liquid system. Magnetic and Magnetorheological properties are studied and results indicate that: instead of decreasing stress with increasing temperature we have observed an increase until 40°C and thereafter, it decreases. This is explained based on, inter and intra particles/chain interaction as well as synergetic effect between small and large sized magnetic dispersion.

Nanofluids revisited

“…Another part of the car that could improve by nanofluids is the damping system: Magnetorheological fluids allows for continuous adjustment of dampers by electromagnets. To overcome the problem of settling of the micrometer sized particles, scientists suggested the use of additional nanoparticles to improve stability [97,98].…”

Thermorheological properties of nano-magnetorheological fluid in dynamic mode: experimental investigation

“…The x-ray diffraction pattern of Fe 3 O 4 particles is recorded at room temperature. The pattern reveals the formation of a single-phase spinel structure [8]. It is obtained from Scherrer's formula [9] that the average size for small-sized and large-sized magnetite particle samples are 10 ± 1 and 20 ± 2 nm, respectively.…”

“…From the rheological studies, it has been concluded that by loading a 30 nm particle size-based MF into a 10 nm particle-sized MF at a maximum weight fraction of 4.44, a maximum yield stress of 246 Pa can be achieved, which is nearly two orders of magnitude higher than that for a pure MF. Furthermore, Shah et al [7] also investigated the temperature-dependent properties of nano-sized particle ferrofluids in a steady shear mode [8]. In this study, the bidisperse suspension has been used, which is prepared using 10 nm and 20 nm of magnetite particles dispersed in a carrier liquid in an appropriate weight fraction.…”