An experimental study on the effects of temperature and magnetic field strength on the magnetorheological fluid stability and MR effect

Soft Matter ◽  
2015 ◽  
Vol 11 (22) ◽  
pp. 4453-4460 ◽  
Author(s):  
Yahya Rabbani ◽  
Mahshid Ashtiani ◽  
Seyed Hassan Hashemabadi

In this study, the stability and rheological properties of a suspension of carbonyl iron microparticles (CIMs) in silicone oil were investigated within a temperature range of 10 to 85 °C.

Author(s):  
Chuncheng Yang ◽  
Zhong Liu ◽  
Xiangyu Pei ◽  
Cuiling Jin ◽  
Mengchun Yu ◽  
...  

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.


2021 ◽  
Vol 8 ◽  
Author(s):  
Yu Tong ◽  
Xiaoguang Li ◽  
Penghui Zhao ◽  
Xufeng Dong ◽  
Zhanjun Wu ◽  
...  

The interface between the particles and the carrier fluids has an important influence on the performance of magnetorheological fluid (MRF). In this study, ionic liquids and silicone oils with the same viscosity and different surface tensions were used as carrier fluids to prepare two different carbonyl iron powder (CIP) magnetorheological fluids. The rheological properties of the two magnetorheological fluids were evaluated by the MCR301 rotating rheometer. The experimental results indicate that ionic liquid-based MRF showed higher shear yield strength and more significant MR effect than silicone oil-based ones in higher magnetic field strength. A possible explanation was proposed and proved through experimental data analysis.


1974 ◽  
Vol 52 (22) ◽  
pp. 2246-2249 ◽  
Author(s):  
H. W. H. Van Andel ◽  
M. T. Churchland ◽  
G. Calabrese

A plasma produced by a helical RF structure of the Lisitano type is investigated. Measurements of electron density, electron temperature, and plasma stability are reported as a function of RF frequency and power, magnetic field strength and geometry, and neutral argon pressure. It is concluded that at moderate power (~20 W), electron cyclotron resonance is important in the power absorption process.


2018 ◽  
Vol 772 ◽  
pp. 61-65
Author(s):  
Muntaz Hana Ahmad Khairi ◽  
Saiful Amri Mazlan ◽  
Ubaidillah ◽  
Siti Aishah Abdul Aziz ◽  
Norhiwani Mohd Hapipi

This study introduces a sucrose acetate isobutyrate (SAIB) as an additive of magnetorheological elastomers (MREs) to be added in silicone rubber matrix and carbonyl iron particles (CIPs) as their filler. The CIPs were fixed at 60 wt% and two types of MREs sample were fabricated which are isotropic and anisotropic. Rheological properties related to shear storage modulus were measured using a rheometer (MCR 302, Anton Paar). The experimental results demonstrated that the magnetorheological (MR) effect of anisotropic MREs-based Silicone/SAIB was 126 % as compared to isotropic MREs-based Silicone/SAIB, 64%. The fabricated MREs samples were frequency and strain dependent. The relative MR effect for both samples showed decreasing trend with the increment of strain amplitude and excitation frequency.


2017 ◽  
Vol 29 (1) ◽  
pp. 137-146 ◽  
Author(s):  
Kwang Pyo Hong ◽  
Ki Hyeok Song ◽  
Myeong Woo Cho ◽  
Seung Hyuk Kwon ◽  
Hyoung Jin Choi

While magnetorheological fluids can be used for ultra-precise polishing, for example, of advanced optical components, oxidation of metallic particles in water-based magnetorheological fluids causes irregular polishing behavior. In this study, carbonyl iron microspheres were initially coated with silica to prevent oxidation and were used to polish BK7 glass. In addition, their rheological and sedimentation characterizations were investigated. Material removal and surface roughness were analyzed to investigate the surface quality and optimal experimental conditions of polishing wheel speed and magnetic field intensity. The maximum material removal was 0.95 µm at 95.52 kA/m magnetic field intensity and 1854 mm/s wheel speed. A very fine surface roughness of 0.87 nm was achieved using the silica-coated magnetorheological fluid at 47.76 kA/m magnetic field intensity and 1854 mm/s wheel speed.


2012 ◽  
Vol 565 ◽  
pp. 273-277
Author(s):  
Shao Hui Yin ◽  
Zhen Yong Cheng ◽  
Zhi Qiang Xu ◽  
Feng Jun Chen ◽  
Jian Wu Yu

Silicone oil based magnetic compound fluid was prepared to polishing stainless steel in this paper. The new fluid consists of nano-sized magnetite particle, micro-sized diamonds, micro-sized iron particle and α-cellulose. The characteristics of the fluid were analyzed. The length and quality of the magnetic cluster in the compound fluid was observed under a magnetic field. Polishing experiment of stainless steel was conducted using the silicone oil based magnetic compound fluid on an inclined polishing finishing device. The micro morphology of the stainless steel’s surface was measured. The results showed the surface quality was improved remarkably and the final roughness of the surface was Ra (Average roughness) 0.020μm.


2011 ◽  
Vol 287-290 ◽  
pp. 2785-2788
Author(s):  
Nan Hui Yu ◽  
Ji Jun Fan

Owing to its unique properties and wide engineering applications, magnetorheological fluids (MRF) has become a hot study area in the field of smart materials. In this paper experimental study of the microwave reflection behavior in MRF was carried out. The results indicated that at the same frequency the microwave reflectivity of MRF decreased with the increasing of magnetic field strength; and with the particle concentration increasing, microwave reflectivity first increased, then decreased, there is a critical concentration of 15%. Under the same magnetic field, with the increasing of microwave frequency, it first decreased, there is a lowest point at 9.2GHz, and then it increased. Usually, it is considered that the change of internal structure of MRF under external magnetic field is the main reason for the regulation behavior of microwave reflectivity.


Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2653
Author(s):  
Fang Chen ◽  
Xiaobing Liu ◽  
Zhenggui Li ◽  
Shengnan Yan ◽  
Hao Fu ◽  
...  

The rheological properties of ferrofluids are related to various applications, such as sealing and loudspeakers, and have therefore attracted widespread attention. However, the rheological properties and their influence on the mechanisms of perfluoropolyether oil (PFPE oil)-based ferrofluids are complicated and not clear. Here, a series of PFPE oil-based ferrofluids were synthesized via a chemical co-precipitation method, and their rheological properties were revealed, systematically. The results indicate that the prepared Zn-ferrite particles have an average size of 12.1 nm, within a range of 4–18 nm, and that the ferrofluids have excellent dispersion stability. The activity of the ferrofluids changes from Newtonian to non-Newtonian, then to solid-like with increasing w from 10 wt% to 45.5 wt%, owing to their variation in microstructures. The viscosity of the ferrofluids increases with increasing Mw (the molecular weight of base liquid PFPE oil polymer), attributed to the increase in entanglements between PFPE oil molecules. The magnetization temperature variation of Zn-ferrite nanoparticles and viscosity temperature variation of PFPE oil together contribute to the viscosity temperature change in ferrofluids. The viscosity of the ferrofluids basically remains unchanged when shear rate is above 50 s−1, with increasing magnetic field strength; however, it first increases and then levels off when the rate is under 10 s−1, revealing that the shear rate and magnetic field strength together affect viscosity. The viscosity and its alteration in Zn-ferrite/PFPE oil-based ferrofluids could be deduced through our work, which will be greatly significant in basic theoretical research and in various applications.


2005 ◽  
Vol 12 (4) ◽  
pp. 411-415 ◽  
Author(s):  
Hua-jin Pan ◽  
Hong-jun Huang ◽  
Ling-zhen Zhang ◽  
Jian-ying Qi ◽  
Shao-kun Cao

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