scholarly journals Gelatine-Coated Carbonyl Iron Particles and Their Utilization in Magnetorheological Suspensions

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2503
Author(s):  
Tomas Plachy ◽  
Patrik Rohrer ◽  
Pavlina Holcapkova
Keyword(s):  
Magnetic Field ◽  
Liquid Medium ◽  
Carbonyl Iron ◽  
Magnetic Particles ◽  
Silicone Oil ◽  
Rheological Parameters ◽  
Iron Particles ◽  
Magnetorheological Suspensions ◽  
Magnetorheological Suspension ◽  
Dynamic Yield

This study demonstrates the formation of biocompatible magnetic particles into organized structures upon the application of an external magnetic field. The capability to create the structures was examined in silicone-oil suspensions and in a gelatine solution, which is commonly used as a blood plasma expander. Firstly, the carbonyl iron particles were successfully coated with gelatine, mixed with a liquid medium in order to form a magnetorheological suspension, and subsequently the possibility of controlling their rheological parameters via a magnetic field was observed using a rotational rheometer with an external magnetic cell. Scanning electron microscopy, infrared spectroscopy, and thermogravimetric analysis confirmed the successful coating process. The prepared magnetorheological suspensions exhibited a transition from pseudoplastic to Bingham behavior, which confirms their capability to create chain-like structures upon application of a magnetic field, which thus prevents the liquid medium from flowing. The observed dynamic yield stresses were calculated using Robertson–Stiff model, which fit the flow curves of the prepared magnetorheological suspensions well.

Encapsulation of Carbonyl Iron Particles with Poly(Vinyl Butyral) and their Magnetorheology

2007 ◽  
Vol 334-335 ◽  
pp. 193-196
Author(s):  
Jae Lim You ◽  
B.J. Park ◽  
I.B. Jang ◽  
Hyoung Jin Choi
Keyword(s):  
Magnetic Field ◽  
Carbonyl Iron ◽  
Magnetic Particles ◽  
Mineral Oil ◽  
Iron Particles ◽  
Carrier Liquid ◽  
Mr Fluids ◽  
Fluid Systems ◽  
Ft Ir ◽  
Vinyl Butyral

To enhance dispersion stability of magnetorheological (MR) fluids, hybrid magnetic particles of carbonyl iron (CI)/ poly(vinyl butyral) (PVB) with core/shell microstrcutre (CI-PVB) were prepared, since pure magnetic CI based MR fluid systems show severe sedimentation of the CI particles due to the large density mismatch with the carrier liquid and difficulties in redispersion after caking. The composite particles of CI-PVB have a lower density than that of the pure CI particles, while exhibiting almost original magnetic property of the CI. Both CI and CI-PVB particles were dispersed in mineral oil (20 vol%) and their MR characteristics were examined via a rotational rheometer with a magnetic field supplier. Various characterizations of the CI-PVB particles were performed via SEM, TEM and FT-IR. Both yield stress and flow curve of shear stress as a function of shear rate of the MR fluids were investigated under applied magnetic field strengths.

HEXAGON-STRIPE TRANSITION AT THE MAGNETIC FIELD INDUCED PHASE TRANSFORMATIONS OF THE MAGNETORHEOLOGICAL SUSPENSIONS

2002 ◽  
Vol 16 (17n18) ◽  
pp. 2345-2351 ◽  
Author(s):  
A. CEBERS
Keyword(s):  
Magnetic Field ◽  
Numerical Simulation ◽  
Physical Parameters ◽  
Phase Boundaries ◽  
Modulated Phases ◽  
Magnetorheological Suspensions ◽  
Perturbed State ◽  
Magnetorheological Suspension ◽  
The Magnetic Field ◽  
Hele Shaw Cell

The phase diagram of the magnetorheological suspension allowing for the modulated phases in the Hele-Shaw cell under the action of the normal field is calculated. The phase boundaries between the stripe, the hexagonal and the unmodulated phases in dependence on the layer thickness and the magnetic field strength are found. The existence of the transitions between the stripe and the hexagonal phases at the corresponding variation of the physical parameters is illustrated by the numerical simulation of the concentration dynamics in the Hele-Shaw cell. It is remarked that those transitions in the case of the magnetorheological suspensions can be caused by the compression or the expansion of the layer. Among the features noticed at the numerical simulation of the concentration dynamics in the Hele-Shaw cell are: the stripe patterns formed from the preexisting hexagonal structures are more ordered than arising from the initial randomly perturbed state; at the slightly perturbed boundary between the concentrated and diluted phases the hexagonal and the inverted hexagonal phases are formed and others.

Investigation of Magnetorheological Suspensions by Optical Methods

2009 ◽  
Vol 152-153 ◽  
pp. 151-154
Author(s):  
L.V. Nikitin ◽  
D.N. Kudryavcev ◽  
I.V. Shashkov ◽  
A.P. Kazakov
Keyword(s):  
Magnetic Field ◽  
Composite Materials ◽  
Uniform Magnetic Field ◽  
Magnetic Particles ◽  
Raw Materials ◽  
Optical Methods ◽  
Magnetic Clusters ◽  
Liquid Polymer ◽  
Synthetic Rubber ◽  
Magnetorheological Suspensions

In this work we studied magnetorheological suspensions, which are produced by dispersion of magnetic particles in liquid polymer matrix, based on natural and synthetic rubber. Such suspensions are the raw materials for creation of new high-elastic magneto-controlled composite materials (magnitoelastics[1-4]). Processes of aggregation and structurization of magnetic particles in suspension are also examined. We discovered that motion of magnetic clusters in oligomer solution has interrupted character. Such behavior can be explained by interaction of magnetic clusters moving in not uniform magnetic field with polymer net fragments. Evaluation of polymer net’s elastic properties was calculated.

scholarly journals Effects of Silicone Oil Viscosity and Carbonyl Iron Particle Weight Fraction and Size on Yield Stress for Magnetorheological Grease Based on a New Preparation Technique

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1778 ◽  
Author(s):  
Kejie Wang ◽  
Xiaomin Dong ◽  
Junli Li ◽  
Kaiyuan Shi ◽  
Keju Li
Keyword(s):  
Yield Stress ◽  
Carbonyl Iron ◽  
Silicone Oil ◽  
Weight Fraction ◽  
Iron Particle ◽  
Preparation Technique ◽  
Oil Viscosity ◽  
Dynamic Yield Stress ◽  
Carbonyl Iron Particle ◽  
Dynamic Yield

This paper investigated the effects of silicone oil viscosity (SOV) and carbonyl iron particle (CIP) weight fraction and size on dynamic yield stress for magnetorheological (MR) grease. The MR grease samples were prepared using orthogonal array L9 on the basis of a new preparation technology. The shear rheological tests were undertaken using a rotational shear rheometer and yield stress was obtained based on the Bingham fluid model. It was found that CIP fractions ranging from 65 wt% to 75 wt% and SOV varying from 50 m2·s−1 to 1000 m2·s−1 significantly affect the magnetic field-dependent yield stress of MR grease, but the CIPs with sizes of 3.2–3.9 μm hardly had any influence based on the analysis of variance (ANOVA). In addition, the yield stress of MR grease mainly depended on the CIP fraction and SOV by comparing their percent contribution (PC). It was further confirmed that there were positive effects of CIP fraction and SOV on yield stress through response surface analysis (RSA). The results showed a high dynamic yield stress. It indicated that MR grease is an intelligent material candidate which can be applied to many different areas requiring high field-induced rheological capabilities without flow for suspension. Moreover, based upon the multivariate regression equation, a constitutive model was developed to express the function of the yield stress as the SOV and fraction of CIPs under the application of magnetic fields.

scholarly journals Magnetorheological Hybrid Elastomers Based on Silicone Rubber and Magnetorheological Suspensions with Graphene Nanoparticles: Effects of the Magnetic Field on the Relative Dielectric Permittivity and Electric Conductivity

2019 ◽  
Vol 20 (17) ◽  
pp. 4201 ◽  
Author(s):  
Bica ◽  
Bunoiu
Keyword(s):  
Magnetic Field ◽  
Dielectric Permittivity ◽  
Silicone Rubber ◽  
Silicone Oil ◽  
Relative Dielectric Permittivity ◽  
Magnetorheological Elastomers ◽  
Magnetorheological Suspensions ◽  
Alternating Electric Field ◽  
Graphene Nanoparticles ◽  
The Magnetic Field

Hybrid magnetorheological elastomers (hMREs) were manufactured based on silicone rubber, silicone oil, carbonyl iron microparticles, graphene nanoparticles and cotton fabric. Using the hMREs, flat capacitors (FCs) were made. Using the installation described in this paper, the electrical capacitance and the coefficient of dielectric losses of the hMREs were measured as a function of the intensity of the magnetic field superimposed over an alternating electric field. From the data obtained, the electrical conductivity, the relative dielectric permittivity and magnetodielectric effects are determined. It is observed that the obtained quantities are significantly influenced by the intensity of the magnetic field and the amount of graphene used.

Preliminary Research on the Post Treatment of Fluid Magnetic Abrasivetool

2010 ◽  
Vol 455 ◽  
pp. 161-164
Author(s):  
W.D. Li ◽  
Ming Lv ◽  
Sheng Qiang Yang
Keyword(s):  
Carbonyl Iron ◽  
Magnetic Particles ◽  
Post Treatment ◽  
Working Time ◽  
Iron Particles ◽  
Abrasive Particles ◽  
Carrier Liquid ◽  
Preliminary Research

Fluid magnetic abrasivetool(FMA) is one kind of latest finishing abrasivetool which is a sort of suspended fluid composed by magnetic particles, nonmagnetic abrasive particles, surfactants in a non-magnetizable carrier liquid. After a period of working time, the performance-life of the abrasivetool ended because of the cutting- blade of the abrasives particles being passive. While the most costly component- the magnetic particles (carbonyl iron particles) can be reused. This paper has made up two recovery flows to separated carbonyl iron particles from others.

Fluid Magnetic Abrasives Based on Micron-Sized Carbonyl-Iron Particles and Its Applications in the Precision Finishing Process

2007 ◽  
Author(s):  
Huanwu Sun ◽  
Shichun Yang
Keyword(s):  
Carbonyl Iron ◽  
Magnetic Particles ◽  
Iron Particles ◽  
Typical Size ◽  
Carrier Liquid ◽  
Finishing Process ◽  
New Type ◽  
Preparation Techniques ◽  
Precision Finishing ◽  
Magnetic Abrasives

The fluid magnetic abrasive (FMA) is a new type of precision finishing abrasives, which is typically prepared by dispersing the magnetic particles, nonmagnetic abrasives, surfactants in a non-magnetizable carrier liquid. As the functional particles, the characteristics of magnetic particles have a great impact on the properties of FMA. In our experiment, the micron-sized carbonyl-iron (CI) particles (typical size: 3 μm–5 μm) are found to be ideally suited for the preparation of FMA. In this paper, the selections of micron-sized carbonyl-iron particles suitable for the FMA, the preparation techniques, the finishing mechanism and finishing process are presented. Some key parameters of FMA that may affect the finishing efficiency and the final surface roughness are analyzed theoretically. The experimental results are discussed as well in this paper.

PHOSPHATE COATING ON THE SURFACE OF CARBONYL IRON POWDER AND ITS EFFECT IN MAGNETORHEOLOGICAL SUSPENSIONS

2007 ◽  
Vol 21 (28n29) ◽  
pp. 4858-4867 ◽  
Author(s):  
ANTONIO J. F. BOMBARD ◽  
MARCELO KNOBEL ◽  
MARIA REGINA ALCÂNTARA
Keyword(s):  
Magnetic Field ◽  
Shear Rate ◽  
Iron Powder ◽  
Carbonyl Iron ◽  
Specific Interaction ◽  
Phosphate Coating ◽  
Flow Curves ◽  
Magnetorheological Suspensions ◽  
Flow Experiments ◽  
Evident Difference

Two types of carbonyl iron powders, (CIP's, BASF AG), the HS and HS-I (I = insulated, due a coating with phosphate), and two kinds of silica, one hydrophobic (Cab-O-Sil® TS610) and other hydrophilic (Cab-O-Sil® M5), were used to evaluate the influence of the surface treatment of the magnetic particle and the kind of fumed silica on the formulation of some magnetorheological suspensions (MRS). Oscillatory measurements at no field showed an evident difference between the silicas, but not a specific interaction with the phosphate coating on HSI. On the other hand, steady flow experiments also without magnetic field showed that the kind of silica and its specific interactions with the coating on iron powder drove the rheological behavior of the MRS on all region of the shear rate. Under magnetic field, the flow curves differences will be due to the iron particles and its magnetic properties, mainly on the region of higher shear rate.

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