Rheological Performance of Magnetorheological Grease with Embedded Graphite Additives

Nasir, Nur Alyaa Mohd; Nazmi, Nurhazimah; Mohamad, Norzilawati; Ubaidillah, Ubaidillah; Nordin, Nur Azmah; Mazlan, Saiful Amri; Aziz, Siti Aishah Abdul; Shabdin, Muhammad Kashfi; Yunus, Nor Alafiza

doi:10.3390/ma14175091

Cited by 14 publications

(4 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As a result, the Gr moves and creates a more structured distribution, thus allowing more current to pass through the structure. This phenomenon was also observed by Nasir et al [ 41 ].…”

Section: Resultssupporting

confidence: 84%

The Effect of Graphite Additives on Magnetization, Resistivity and Electrical Conductivity of Magnetorheological Plastomer

et al. 2021

Self Cite

View full text Add to dashboard Cite

Common sensors in many applications are in the form of rigid devices that can react according to external stimuli. However, a magnetorheological plastomer (MRP) can offer a new type of sensing capability, as it is flexible in shape, soft, and responsive to an external magnetic field. In this study, graphite (Gr) particles are introduced into an MRP as an additive, to investigate the advantages of its electrical properties in MRPs, such as conductivity, which is absolutely required in a potential sensor. As a first step to achieve this, MRP samples containing carbonyl iron particles (CIPs) and various amounts of of Gr, from 0 to 10 wt.%, are prepared, and their magnetic-field-dependent electrical properties are experimentally evaluated. After the morphological aspect of Gr–MRP is characterized using environmental scanning electron microscopy (ESEM), the magnetic properties of MRP and Gr–MRP are evaluated via a vibrating sample magnetometer (VSM). The resistivities of the Gr–MRP samples are then tested under various applied magnetic flux densities, showing that the resistivity of Gr–MRP decreases with increasing of Gr content up to 10 wt.%. In addition, the electrical conductivity is tested using a test rig, showing that the conductivity increases as the amount of Gr additive increases, up to 10 wt.%. The conductivity of 10 wt.% Gr–MRP is found to be highest, at 178.06% higher than the Gr–MRP with 6 wt.%, for a magnetic flux density of 400 mT. It is observed that with the addition of Gr, the conductivity properties are improved with increases in the magnetic flux density, which could contribute to the potential usefulness of these materials as sensing detection devices.

show abstract

“…As a result, the Gr moves and creates a more structured distribution, thus allowing more current to pass through the structure. This phenomenon was also observed by Nasir et al [ 41 ].…”

Section: Resultssupporting

confidence: 84%

The Effect of Graphite Additives on Magnetization, Resistivity and Electrical Conductivity of Magnetorheological Plastomer

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

“…The maximum yield stress and MR effect can reach about 52.7 kPa and 952.38%. Based on the present research status, the differences among the microstructure with different carrier greases have a great impact on the MR properties of MR grease [29]. Therefore, the influence of key parameters with composite MR grease is not enough.…”

Section: Introductionmentioning

confidence: 78%

Studies with Rheological Behavior of Composite Lithium-Based Magnetorheological Grease

Yan¹,

Duan

et al. 2021

Metals

View full text Add to dashboard Cite

Magnetorheological (MR) grease has advantages of the anti-settlement behavior and excellent sealing property compared with conventional MR materials. However, the rheological behaviors of MR effect and shear yield stress are too small to limit the further applications with MR grease. This paper proposes a composite lithium-based MR grease with boric acid-hydroxyl stearic acid to improve the rheological behaviors. Eight different samples of composite lithium-based MR grease with different ratios of mass between lithium stearate and lithium borate are prepared by the saponification method. The rheological behaviors are tested and discussed with qualitative and quantitative analysis. The experimental results show that the off-state viscosity reduces with the decrement of the ratio of mass under low shear rate which changes from 68.7 Pa·s to 16.5 Pa·s. Lithium stearate content has more effects with off-state viscosity. Based on the Herschel-Bingham model, the shear stress of composite lithium-based MR grease can be improved dramatically by adjusting the ratio of mass which is increased by 170% under the magnetic flux density of 0.2 T. Compared with single lithium-based MR grease, the maximum yield shear stress is increased by 166.7% at off-state and the maximum MR effect is also increased by 19.1%. The MR effect can reach 23,600% with a specific mass ratio of the composite MR grease. The experimental results validate that the feasibility of the performance improvement by the composite lithium-based MR grease.

show abstract

“…Magnetic elastomers are one of the stimulus-responsive soft materials, i.e., materials whose physical properties change in response to magnetic fields, e.g., macroscopic expansion and contraction under gradient magnetic fields, magnetostriction, rotational motion under rotational magnetic fields, magnetorheological greases, multiferroic cantilevers, adhesion and friction properties due to magnetic switching, tunable vibration–absorption, and variable surface microstructure. , Magnetic elastomers consisting of polymer matrix and magnetic particles generally undergo a large magnetic response and are expected to be practical actuators. When a magnetic field is applied to a magnetic elastomer, the elasticity increases due to the formation of a chain-like structure of the magnetic particles (restructuring), known as the magnetorheological (MR) effect.…”

Section: Introductionmentioning

confidence: 99%

Extremely Long Chains of Magnetic Particles via Large Plastic Beads Observed in Bimodal Magnetic Elastomers

et al. 2023

View full text Add to dashboard Cite

The relationship between the magnetorheology of bimodal magnetic elastomers with high concentrations (60 vol %) of plastic beads with diameters of 8 or 200 μm and the meso-structure of the particles was investigated. Dynamic viscoelasticity measurements revealed that the change in storage modulus of the bimodal elastomer with 200 μm beads was 2.8 × 10 5 Pa at a magnetic field of 370 mT. The change in the storage modulus for monomodal elastomer without beads was 4.9 × 10 4 Pa. The bimodal elastomer with 8 μm beads hardly responded to the magnetic field. In-situ observation for the particle morphology was performed using synchrotron X-ray CT. For the bimodal elastomer with 200 μm beads, a highly aligned structure of magnetic particles was observed in the gaps between the beads when the magnetic field was applied. On the other hand, for the bimodal elastomer with 8 μm beads, no chain structure of magnetic particles was observed. The orientation angle between the long axis of the aggregation of magnetic particles and the magnetic field direction was determined by an image analysis in three dimensions. The orientation angle varied from 56°to 11°for the bimodal elastomer with 200 μm beads and from 64°to 49°for that with 8 μm beads by applying the magnetic field. The orientation angle of the monomodal elastomer without beads changed from 63°to 21°. It was found that the addition of beads with a diameter of 200 μm linked the chains of magnetic particles, while beads with a diameter of 8 μm prevented the chain formation of the magnetic particles.

show abstract

Rheological Performance of Magnetorheological Grease with Embedded Graphite Additives

Cited by 14 publications

References 40 publications

The Effect of Graphite Additives on Magnetization, Resistivity and Electrical Conductivity of Magnetorheological Plastomer

The Effect of Graphite Additives on Magnetization, Resistivity and Electrical Conductivity of Magnetorheological Plastomer

Studies with Rheological Behavior of Composite Lithium-Based Magnetorheological Grease

Extremely Long Chains of Magnetic Particles via Large Plastic Beads Observed in Bimodal Magnetic Elastomers

Contact Info

Product

Resources

About