Temperature-dependent material properties of the components of magnetorheological fluids

Abstract

Material properties of the components of magnetorheological (MR) fluids are critical to their control accuracy and service life. The aim of this study was to reveal the effects of temperature on the material properties of MR fluid components. In this paper, a detailed introduction to the components of MR fluids, including main performance indicators and commonly used materials, was presented at first. Then, theoretical analysis and experimental investigation were performed on the temperature-dependent material properties of MR fluid components. These material properties included the magnetization properties of the magnetic particle, as well as the shear viscosity and thermal expansion of the carrier fluid. Experimental results indicated that both the mass magnetization and coercivity of MR particles decreased as the temperature increased and the phenomenon was particularly obvious at high temperatures. Moreover, an increasing temperature could lead to a severe decrease of the shear viscosity and a relatively large thermal expansion of the carrier fluid. Research results from this study may serve to provide a theoretical and an experimental basis for the preparation of MR fluids with high thermal stability.

Influence Factor on Magnetization Property of Carbonyl Iron-based Magnetorheological Fluids

“…6, the saturation magnetizations of MRFs samples before & after surfactant coating are about 135.9 emu/g and 145.2 emu/g, respectively. According to the measured hysteresis loop of 7 µm-sized carbonyl iron particle in Literature [4], the saturation magnetization of magnetic particles at RT is nearly 204.2 emu/g. Obviously, the saturation magnetization of MRFs samples after surfactant coating is slightly higher than the product of the particle saturation magnetization and the particle mass fraction (that is, 204.2 emu/g × 66.9 % = 136.6 emu/g).…”

“…Magnetorheological fluids (MRFs) are suspensions prepared by dispersing micron-sized magnetic particles uniformly into a carrier liquid [1][2][3][4][5][6]. Meanwhile, a variety of proprietary additives is commonly added to discourage particle sedimentation, improve lubricity and inhibit wear.…”

“…Material properties of MRFs are critical to the working stability, control accuracy and even service life of MRFbased devices [4]. Therefore, considerable research works related to this issue have been carried out.…”

Microrheology of magnetorheological silicone elastomers during curing process under the presence of magnetic field

“…4(a). 2,8,12,13,24 The dipole magnetic force drives the SiCIPs to form a relatively stable chain-like structure that suppresses the thermal movements of SiCIPs and improves the elasticity of MREs, especially within initial aging time of 2 h. [2][3][4][5][6] With increasing magnetic field intensity, the dipole magnetic forces become pronounced and intensively interfere the thermal movements of SiCIPs, leading to higher EI values. The equilibrium EI values at long times exhibit the increasing tendency at high magnetic field intensity and SiCIPs content, demonstrating the effect of magnetic field-induced formation of chain-like structure that couples with the jamming effect of MREs in the cured silicone matrix.…”

“…[1][2][3][4] Rabinow first proposed a kind of MRFs and settles the general form by suspending magnetic particles in a carrier oil. 5 Ginder proposed a representative model describing the magnetization of particles and the rheological characteristics of MRFs varying with magnetic field intensity.…”