Effect of Particle Size on Shear Stress of Magnetorheological Fluids
Effect of Particle Size on Shear Stress of Magnetorheological Fluids
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DOI：
10.1080/23080477.2015.11665638
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发表时间：
2015-01
期刊：
影响因子：
2.3
通讯作者：
C. Sarkar;H. Hirani
中科院分区：
文献类型：
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作者：
C. Sarkar;H. Hirani
磁流变液（MRF）以其可变的剪切应力而闻名，其在可磁化的载液中含有可磁化的微米级颗粒（几微米至200微米）。为了避免颗粒沉降，优选较小尺寸（3-10微米）的颗粒，而较大尺寸的颗粒可用于MR制动器、MR离合器等，因为这些机构中的机械搅拌作用不允许颗粒沉降。理想地，与较小尺寸的颗粒相比，较大尺寸的颗粒提供更高的剪切应力。然而，需要探索颗粒尺寸对剪切应力的影响。本文比较了不同粒径颗粒对磁流变效应的影响。使用HORIBA激光散射粒度分布分析仪测量铁颗粒的粒度分布。给出了粒度分布、平均粒度和标准偏差。使用扫描电子显微镜观察颗粒形状的性质。为了探索颗粒尺寸的影响，已经合成了九种含有小的、大的和混合尺寸的羰基铁颗粒的MR流体。对于每种尺寸的颗粒，使用了三种浓度（9%、18%和36%体积）。用ANTON帕尔MCR-102流变仪测定了这些磁流变液试样的剪切应力。随着铁颗粒体积分数的增加，使用“混合尺寸的颗粒”合成的MR流体显示出更好的剪切应力相比，含有“较小尺寸的球形颗粒”和“较大尺寸的片状形状的颗粒”的MR流体在较高的剪切速率。
Magnetorheological fluids (MRF), known for their variable shear stress contain magnetisable micrometer-sized particles (few micrometer to 200 micrometers) in a nonmagnetic carrier liquid. To avoid settling of particles, smaller sized (3–10 micrometers) particles are preferred, while larger sized particles can be used in MR brakes, MR clutches, etc. as mechanical stirring action in those mechanisms does not allow particles to settle down. Ideally larger sized particles provide higher shear stress compared to smaller sized particles. However there is need to explore the effect of particle sizes on the shear stress. In the current paper, a comparison of different particle sizes on MR effect has been presented. Particle size distributions of iron particles were measured using HORIBA Laser Scattering Particle Size Distribution Analyser. The particle size distribution, mean sizes and standard deviations have been presented. The nature of particle shapes has been observed using scanning electron microscopy. To explore the effect of particle sizes, nine MR fluids containing small, large and mixed sized carbonyl iron particles have been synthesized. Three concentrations (9%, 18% and 36% by volume) for each size of particles have been used. The shear stresses of those MRF samples have been measured using ANTON PAAR MCR-102 Rheometer. With increase in volume fraction of iron particles, the MR fluids synthesized using “mixed sized particles” show better shear stress compared to the MR fluids containing “smaller sized spherical shaped particles” and “larger sized flaked shaped particles” at higher shear rate.