Soft magnetic carbonyl iron microsphere dispersed in grease and its rheological characteristics under magnetic field

Park, Byung O.; Park, Bong Jun; Hato, Mpitloane J.; Choi, Hyoung Jin

doi:10.1007/s00396-010-2363-y

Cited by 76 publications

(65 citation statements)

References 36 publications

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“…Magnetorheological elastomers (MREs) are composites, and the magnetic particles are suspended in a rubber matrix. The magnetic particles inside the elastomer can be homogeneously distributed or they can be grouped . Structurally, MRE can be thought of as solid analogs of MR fluid .…”

Section: Introductionmentioning

confidence: 99%

Dynamic mechanical properties of magnetorheological elastomers based on polyurethane matrix

Ju¹,

Tang²,

Zhang³

et al. 2014

Polymer Composites

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Magnetorheological elastomers (MRE) are mainly composed of soft magnetic particles and rubber-like matrix. Previous studies have shown that the matrix has a greater impact on mechanical properties of MRE. In this article, a new kind of polyurethane material was fabricated and used as the matrix of MRE. The effect of several factors on the mechanical properties of MRE samples was experimentally studied, such as fabrication condition, content of iron particles, different weight ratio of castor oil and diphenylmethane diisocyanate, plasticizer. Their microstructures were observed, and the mechanical properties were measured using a testing system in the presence of an external magnetic field. The experimental results demonstrate that these factors have different impact on shear storage modulus, magneto-induced modulus, MR effect and damping property. In addition, the damping property of these MRE is also higher than that of MRE based on the other matrix. This study can hopefully be applied to optimize the mechanical properties of MRE. POLYM. COMPOS., 00:000-000, 2014.

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Section: Introductionmentioning

confidence: 99%

Dynamic mechanical properties of magnetorheological elastomers based on polyurethane matrix

Ju¹,

Tang²,

Zhang³

et al. 2014

Polymer Composites

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“…In matrix fluids composed of viscoplastic grease, Rankin et al (1999) reported that the field-induced dynamic yield stress scales with B x , where x decreases from about 1.5 to 0 as the magnetic field increases and the magnetization of the particles saturates. The value of x = 1.5 in grease-based matrix fluids for magnetic fields below the saturation regime (about 0.05 T to 0.35 T) has also been reported by other authors Park et al 2011). …”

Section: Effects Of Magnetic Field and Agingmentioning

confidence: 58%

“…Arguably the most robust methods for inhibiting sedimentation involve modifying the matrix fluid rheological properties. By employing viscoplastic matrix fluids (Rankin et al 1999;Park et al 2011) or thixotropic gel-forming agents such as silica nanoparticles (de Vicente et al 2003;Lopez-Lopez et al 2006), sedimentation can be prevented essentially indefinitely in quiescent dispersions as long as the yield stress of the matrix fluid exceeds the net stress acting on the particles due to gravity and buoyancy (Chhabra 1993).…”

Section: Introductionmentioning

confidence: 99%

Magnetorheology in an aging, yield stress matrix fluid

2012

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Field-induced static and dynamic yield stresses are explored for magnetorheological (MR) suspensions in an aging, yield stress matrix fluid composed of an aqueous dispersion of Laponite ® clay. Using a custom-built magnetorheometry fixture, the MR response is studied for magnetic field strengths up to 1 T and magnetic particle concentrations up to 30 v%. The yield stress of the matrix fluid, which serves to inhibit sedimentation of dispersed carbonyl iron magnetic microparticles, is found to have a negligible effect on the field-induced static yield stress for sufficient applied fields, and good agreement is observed between field-induced static and dynamic yield stresses for all but the lowest field strengths and particle concentrations. These results, which generally imply a dominance of inter-particle dipolar interactions over the matrix fluid yield stress, are analyzed by considering a dimensionless magnetic yield parameter that quantifies the balance of stresses on particles. By characterizing the applied magnetic field in terms of the average particle magnetization, a rheological master curve is generated for the fieldinduced static yield stress that indicates a concentration-magnetization superposition. The results presented herein will provide guidance to formulators of MR fluids and designers of MR devices who require a field-induced static yield stress and a dispersion that is essentially indefinitely stable to sedimentation.

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“…Clearly, this special kind of thermal sensitive characteristic not only reduces the sentimental defects of the traditional MRFs but also supplies a feasible way for multifunctional MR materials. Actually, the previously reported grease-based MR materials also exhibits such a thermal responsive MR behavior [73,74]. Although the physical state of the MR grease has not been demonstrated in the manuscript, it was estimated to be a kind of MRP with a small starting storage modulus, because the authors have claimed that this product had a strong solid-like structure rather than a fluid-like structure under external magnetic field.…”

Section: Magnetorheological Plastomersmentioning

confidence: 86%

“…Different from the MRGs and MRF, the Bingham viscoplastic model is not suitable to describe the mechanical behaviors of the MRPs. Owing to their soft solid-like characteristic, oscillatory shear rheometry has been proven to be a powerful tool to study their mechanical properties [60,65,66,[74][75][76][77]. In the linear viscoelastic range, the highest magneto-induced storage modulus of the PU-based MRP reaches as high as 6.54 MPa, corresponding to a relative MR effect of 532% (Figure 2(a)).…”

Section: Magnetorheological Plastomersmentioning

confidence: 99%

Recent progress on the magnetorheological plastomers

Xuan

Liu

et al. 2015

International Journal of Smart and Nano Materials

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Different from the traditional magnetorheological (MR) fluids and elastomers, the magnetic particles in the plastic MR materials are not 'deadly' trapped in the polymer matrix; thus, the MR plastomers exhibit higher MR effects and lower sedimentation. The plastic MR materials have attracted increasing attention, and the relevant fundamental mechanisms and practical applications have been intensively studied due to their unique physical and mechanical properties. In this highlight, we have mainly reviewed the preparation and the rheological properties of the MR plastomers. The formation mechanism of the MR plastomers has also been briefly summarized.

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Soft magnetic carbonyl iron microsphere dispersed in grease and its rheological characteristics under magnetic field

Cited by 76 publications

References 36 publications

Dynamic mechanical properties of magnetorheological elastomers based on polyurethane matrix

Dynamic mechanical properties of magnetorheological elastomers based on polyurethane matrix

Magnetorheology in an aging, yield stress matrix fluid

Recent progress on the magnetorheological plastomers

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