Enhancement effect of nonferromagnetic particles on the viscosity of magnetorheological fluid under a dynamic magnetic field

2021 ◽  
Vol 14 (06) ◽  
pp. 2151038
Author(s):  
Bingsan Chen ◽  
Cheng Zheng ◽  
Zhongyu Bao ◽  
Chunyu Li ◽  
Dicheng Huang
Keyword(s):  
Magnetic Field ◽  
Glass Powder ◽  
Magnetorheological Fluid ◽  
Calculation Model ◽  
Enhancement Effect ◽  
Sedimentation Resistance ◽  
Powder Content ◽  
Dynamic Magnetic Field ◽  
The Magnetic Field ◽  
Made In

This study aims to investigate the effect of nonferromagnetic particle content on the properties of the magnetorheological fluid (MRF) under a dynamic magnetic field. A magnetic-induced viscosity calculation model under the temperature field was built. The influence on the viscosity of the MRF made in-house was analyzed by adding different proportions of nonferromagnetic particles, such as glass powder. Experiments show that a certain proportion of glass powder can increase the viscosity of the MRF. When the powder content is less than 10%, viscosity increases as the glass powder content increases. Conversely, viscosity decreases as the glass powder content increases when the content is more than 10% but less than 20%. These results indicate that adding micron glass powder to the MRF can increase the magnetic saturation limit of the MRF under the dynamic magnetic field and improve its settlement resistance by 25.6%.When 10% glass powder is added to the MRF containing 60% iron powder, sedimentation resistance increases by 25.6%. When the magnetic field intensity is 640 mT, the viscosity of the MRF increases by 6.6 times.

Magnetorheological fluid based on amorphous Fe-Si-B alloy magnetic particles

2021 ◽  
pp. 1045389X2110643
Author(s):  
Chuncheng Yang ◽  
Zhong Liu ◽  
Xiangyu Pei ◽  
Cuiling Jin ◽  
Mengchun Yu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Rheological Property ◽  
Magnetic Particles ◽  
Annealing Treatment ◽  
Magnetorheological Fluid ◽  
The Stability ◽  
The Magnetic Field ◽  
Amorphous Particle ◽  
Better Than

Magnetorheological fluids (MRFs) based on amorphous Fe-Si-B alloy magnetic particles were prepared. The influence of annealing treatment on stability and rheological property of MRFs was investigated. The saturation magnetization ( Ms) of amorphous Fe-Si-B particles after annealing at 550°C is 131.5 emu/g, which is higher than that of amorphous Fe-Si-B particles without annealing. Moreover, the stability of MRF with annealed amorphous Fe-Si-B particles is better than that of MRF without annealed amorphous Fe-Si-B particles. Stearic acid at 3 wt% was added to the MRF2 to enhance the fluid stability to greater than 90%. In addition, the rheological properties demonstrate that the prepared amorphous particle MRF shows relatively strong magnetic responsiveness, especially when the magnetic field strength reaches 365 kA/m. As the magnetic field intensified, the yield stress increased dramatically and followed the Herschel-Bulkley model.

scholarly journals Tribological Evolution of the Superficial Layer and the Effects of the Magnetic Field to a Non- conventional Treated Steel, During Wear Tests

2018 ◽  
Vol 55 (3) ◽  
pp. 442-446
Author(s):  
Carmen Penelopi Papadatu ◽  
Andrei Victor Sandu ◽  
Marian Bordei ◽  
Ioan Gabriel Sandu ◽  
Sorin Ciortan
Keyword(s):  
Magnetic Field ◽  
Mechanical Properties ◽  
Dry Friction ◽  
Experimental Tests ◽  
Superficial Layer ◽  
Alloyed Steel ◽  
Wear Process ◽  
The Magnetic Field ◽  
Wear Tests ◽  
Made In

The article focuses on the behavior of the non-conventional treated alloyed steel in magnetic field, during the dry wear tests. It is a review of the experimental tests from last years. The thermo-magnetic treatments have been applied before the application of a thermo-chemical treatment in plasma based on diffusion process. The study was made in order to improve the mechanical properties of the alloyed steel during the friction wear. Thermo-magnetic treatment applied before the plasma nitro-carburizing treatment improves the mechanical properties of the material especially in this case, for a steel that has a considerable content of Chromium (1.02%). The behavior was studied using X-Ray diffractometry of the superficial layers during the dry friction of wear process. The wear tests used an Amsler machine, during three hours of wear tests. After each hour of the wear tests the samples have been analyzed. The diffractometric characteristics of the superficial layers obtained after a complex array of thermo-magnetic and thermo-chemical in plasma treatments, the phases distribution, the content of the superficial layers and the behavior of the steel during the wear through dry friction tests, have been considered as criteria.

scholarly journals Magnetorheological Fluids Behaviour in Oscillatory Compression Squeeze: Experimental Testing and Analysis

2019 ◽  
Vol 13 (4) ◽  
pp. 221-225
Author(s):  
Wojciech Horak ◽  
Marcin Szczęch ◽  
Bogdan Sapiński
Keyword(s):  
Magnetic Field ◽  
Volume Fraction ◽  
Experimental Testing ◽  
Magnetic Field Gradient ◽  
Particle Volume Fraction ◽  
Excitation Frequency ◽  
Magnetorheological Fluid ◽  
Density Level ◽  
Particle Volume ◽  
The Magnetic Field

Abstract This article deals with experimental testing of magnetorheological fluid (MRF) behaviour in the oscillatory squeeze mode. The authors investigate and analyse the influence of excitation frequency and magnetic field density level on axial force in MRFs that differ in particle volume fraction. The results show that, under certain conditions, the phenomenon of self-sealing can occur as a result of the magnetic field gradient and a vacuum in the working gap of the system.

scholarly journals Magnetorheological Fluid Finishing of Soft Materials: A Critical Review

2019 ◽  
Vol 4 (1) ◽  
pp. 48-55
Author(s):  
Anand Sharma ◽  
M.S. Niranjan
Keyword(s):  
Magnetic Field ◽  
Magnetic Particles ◽  
Soft Materials ◽  
Magnetorheological Fluid ◽  
Magnetorheological Finishing ◽  
Stabilizing Agents ◽  
Optical Glasses ◽  
Finishing Processes ◽  
Precision Finishing ◽  
Made In

Magnetorheological Finishing (MRF) is one of the precision finishing processes and recently commercialized method for finishing of various materials like optical glasses, metals, non-metals etc. This method utilizes a suspension consisting of a fluid carrier which can be water or oil, both magnetic and non-magnetic particles and stabilizing agents. Rheological behavior of this mixture of magnetorheological (MR) fluid with abrasives changes under the influence of magnetic field which in turn regulates the finishing forces during finishing processes. Present study critically reviews the MRF process used for achieving nano-level finishing of soft materials and the advancements made in this process

Influence of Permanent Magnets Installation Approach on the Torque of а Magneto-Rheological Disk Brake

2021 ◽  
Vol 105 ◽  
pp. 184-193
Author(s):  
Ilya Aleksandrovich Frolov ◽  
Andrei Aleksandrovich Vorotnikov ◽  
Semyon Viktorovich Bushuev ◽  
Elena Alekseevna Melnichenko ◽  
Yuri Viktorovich Poduraev
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Magnetic Materials ◽  
Permanent Magnets ◽  
Magnetorheological Fluid ◽  
Simulation Modelling ◽  
Disc Brake ◽  
Large Area ◽  
Braking Torque ◽  
The Magnetic Field

Magnetorheological braking devices function due to the organization of domain structures between liquid and solid magnetic materials under the action of an electromagnetic or magnetic field. The disc is most widely used as a rotating braking element that made of a solid magnetic material due to the large area of contact with a magnetorheological fluid. Many factors affect the braking characteristics of the magnetorheological disc brake. Specifically, the value of the magnetic field and how the field is distributed across the work element is significantly affected at the braking torque. There are different ways to generate a magnetic field. In this study, the method of installation of permanent magnets into the construction, allowing to increase the braking torque of the magnetorheological disc brake is proposed. Simulation modelling showing the distribution of the magnetic field across the disk depending on the installation of permanent magnets with different pole orientations were carried out. The model takes into account the possibility of increasing the gap between solid magnetic materials of the structure, inside them which the magnetorheological fluid is placed. Comparative estimation of the distribution of the magnetic fields depending on the chosen method of installation of permanent magnets with different orientations of their poles is carried out. Further research is planned to focus on a comparative assessment of the distribution of magnetic fields depending on the selected material of the braking chamber.

Design of a Dynamic Magnetic Field Steered Cathodic Arc Source in Arc Ion Plating

2011 ◽  
Vol 340 ◽  
pp. 167-172 ◽  
Author(s):  
Wen Chang Lang
Keyword(s):  
Magnetic Field ◽  
Cathode Surface ◽  
Target Surface ◽  
Target Thickness ◽  
Current Ratio ◽  
Operating Modes ◽  
Electromagnetic Coils ◽  
Cathodic Arc ◽  
Dynamic Magnetic Field ◽  
The Magnetic Field

In this work, a dynamic arched magnetic field steered arc source was deigned by virtue of Finite Element Method (FEM) calculation. The magnetic field was produced by two main electromagnetic coils so that the magnetic field can be adjusted with the help of the two currentI1and I2,whereI1is the current to the internal coil mounted coaxially in a magnetic yoke generating a static arched magnetic field to confine the cathode spots and I2is the current to the external coil mounted coaxially outside the above yoke adjusting the position of the vertex of arch. Base on the results of simulation, it was found this design enable the sweeping of the arc spots on the target surface by means of adjusting the ratio of current (I1/I2) , and cause the arc distribute evenly on the cathode surface in the diffuse arc mode transferred from the constricted arc mode. The effects of the target thickness and current ratio on the configuration and intensity of dynamic arched magnetic field were investigated. The optimized operating modes was proposed and discussed.

scholarly journals The Magnetic Field of the Crab as Revealed by New, High Resolution, Multi-Band Radio Images

1990 ◽  
Vol 140 ◽  
pp. 79-80
Author(s):  
M. F. Bietenholz ◽  
P. P. Kronberg
Keyword(s):  
Magnetic Field ◽  
High Resolution ◽  
Crab Nebula ◽  
Radio Observations ◽  
Field Orientation ◽  
Magnetic Field Orientation ◽  
The Crab Nebula ◽  
The Magnetic Field ◽  
Made In ◽  
Multi Band

We present and describe recent radio observations of the Crab Nebula, which allow us to determine the magnetic field orientation and depolarization at unprecedented resolution. The observations were made in 1987-1988 using all four configurations of the VLA, at 1410,1515,4625, and 4885 MHz. The resulting maps were all convolved with a clean beam of 1.8″ × 2.0″, elongated in P.A. 80°, and the residuals added back in.

scholarly journals Discovery of weak magnetic fields in four DZ white dwarfs in the local 20 pc volume

2019 ◽  
Vol 630 ◽  
pp. A65 ◽  
Author(s):  
S. Bagnulo ◽  
J. D. Landstreet
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
White Dwarfs ◽  
Field Measurements ◽  
Weak Magnetic Fields ◽  
Polluted Atmosphere ◽  
Highly Sensitive ◽  
Cool White Dwarfs ◽  
The Magnetic Field ◽  
Made In

We report the discovery of weak magnetic fields in three white dwarfs within the local 20 pc volume (WD 0816−310, WD 1009−184, and WD 1532+129), and we confirm the magnetic nature of a fourth star (WD 2138−332) in which we had previously detected a field at a 3σ level. The spectra of all these white dwarfs are characterised by the presence of metal lines and lack of H and He lines, that is, they belong to the spectral class DZ. The polarisation signal of the Ca II H+K lines of WD 1009−184 is particularly spectacular, with an amplitude of 20% that is due to the presence of a magnetic field with an average line-of-sight component of 40 kG. We have thus established that at least 40% of the known DZ white dwarfs with an He-rich atmosphere contained in the 20 pc volume have a magnetic field, while further observations are needed to establish whether the remaining DZ white dwarfs in the same volume are magnetic or not. Metal lines in the spectra of DZ white dwarfs are thought to have originated by accretion from rocky debris, and it might be argued that a link exists between metal accretion and higher occurrence of magnetism. However, we are not able to distinguish whether the magnetic field and the presence of a polluted atmosphere have a common origin, or if it is the presence of metal lines that allows us to detect a higher frequency of magnetic fields in cool white dwarfs, which would otherwise have featureless spectra. We argue that the new highly sensitive longitudinal field measurements that we have made in recent years are consistent with the idea that the magnetic field appears more frequently in older than in younger white dwarfs.

Development of a double magnetic circuit yield stress measurement device for magnetorheological fluid

2016 ◽  
Vol 28 (10) ◽  
pp. 1249-1259 ◽  
Author(s):  
Xiang-Fan Wu ◽  
Xing-Ming Xiao ◽  
Zu-Zhi Tian ◽  
Fei Chen ◽  
Jian Wang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Yield Stress ◽  
Magnetic Circuit ◽  
Stress Measurement ◽  
Magnetorheological Fluid ◽  
High Yield ◽  
Magnetic Field Measurement ◽  
Measurement Device ◽  
Accuracy And Repeatability ◽  
The Magnetic Field

On the basis of shear working mode of magnetorheological fluid, in this article, a novel temperature controllable yield stress measurement device is designed, and the double magnetic circuit structure and the heating structure are proposed. And then, the magnetic field and temperature field of the measurement device are simulated, respectively, by the finite element method. Furthermore, several experiments are carried out to evaluate the magnetic field, measurement precision, and repeatability of the self-designed device. The results indicate that the proposed measurement device has uniform magnetic field distribution and controllable temperature and also has high yield stress testing accuracy and repeatability.

ELECTROMAGNETIC FIELDS IN AN N‐LAYER ANISOTROPIC HALF‐SPACE

Geophysics ◽  
1967 ◽  
Vol 32 (4) ◽  
pp. 668-677 ◽  
Author(s):  
Douglas P. O’Brien ◽  
H. F. Morrison
Keyword(s):  
Magnetic Field ◽  
Experimental Data ◽  
Plane Wave ◽  
Half Space ◽  
Electric Fields ◽  
Field Measurements ◽  
Large Scatter ◽  
Tensor Impedance ◽  
The Magnetic Field ◽  
Made In

From Maxwell’s equations and Ohm’s law for a horizontally anisotropic medium, it may be shown that two independent plane wave modes propagate perpendicular to the plane of the anisotropy. Boundary conditions at the interfaces in an n‐layered model permit the calculation, through successive matrix multiplications, of the fields at the surface in terms of the fields propagated into the basal infinite half space. Specifying the magnetic field at the surface allows the calculation of the resultant electric fields, and the calculation of the entries of a tensor impedance relationship. These calculations have been programmed for the digital computer and an interpretation of impedances obtained from field measurements may thus be made in terms of the anisotropic layering. In addition, apparent resistivities in orthogonal directions have been calculated for specific models and compared to experimental data. It is apparent that the large scatter of observed resistivities can be caused by small changes in the polarization of the magnetic field.

Sign in / Sign up

Export Citation Format

Share Document