Magnetic Friction Research Articles

Suitable Method for Improving Friction Performance of Magnetic Wheels with Metal Yokes

A magnetic-wheeled robot is a type of robot that inspects large steel structures instead of humans, and it can run on a three-dimensional path by using wheels with built-in permanent magnets. For the robots to work safely, their magnetic wheels require both magnetic attractive forces and friction forces. Planetary-geared magnetic wheels, which we have developed, make direct contact with their yokes on the running surface to ensure their magnetic attractive force. However, this design decreases their frictional performance more than common magnetic wheels covered with soft materials. Therefore, the yokes require methods that can improve their frictional performance without decreasing their attractive force. To consider the best method for the use of magnetic wheels, this study has run experiments with five types of yokes, which have different processing. As a result, the yokes with corroded surfaces could have maintained the attractive force more than 90% of the time and increased their traction forces by about 36% in static conditions and about 30% in dynamic conditions compared to yokes with no machining. The main reasons for these experimental results are that the rust layer has stable irregularities on the surface and includes ferromagnetic materials.

Significant Improvement in Magnetorheological Performance by Controlling Micron Interspaces with High Permeability Submicron Particles.

The shear yield strength, sedimentation stability and zero-field viscosity of magnetorheological fluids (MRFs) are crucial for practical vibration damping applications, yet achieving a balanced combination of these performances remains challenging. Developing MRFs with excellent comprehensive performance is key to advancing smart vibration damping technologies further. Theoretically, incorporating a multiscale particle system and leveraging synergistic effects between their can somewhat enhance MRFs' performance. However, this approach often faces issues such as insignificant increases in shear yield strength and excessive rise in zero-field viscosity. In response, this study employs a DC arc plasma method to synthesize a high magnetic permeability, low coercivity submicron FeNi particles, and further develops a novel CIPs-FeNi bidisperse MRFs. The introduction of submicron FeNi particles not only significantly enhances the shear2019 yield strength of MRFs under low magnetic fields but also promotes improvements in sedimentation stability and redispersibility without excessively increasing viscosity. Comprehensive performance analysis is conducted to explore the optimal content ratio, and detailed mechanisms for the enhancement of performance are elucidated through analysis of parameters such as chain-like structure, magnetic flux density and friction coefficient. Most importantly, the superior comprehensive performance combined with straightforward fabrication methods significantly enhances the engineering applicability of the CIPs-FeNi bidisperse MRFs.

Effects of boron on microstructure, wear and corrosion properties of external magnetic field assisted laser metal deposition coatings

Coatings with different boron content were prepared by magnetic field-assisted Co-based laser metal deposition on 300 M ultra-high strength steel. The effects of boron content on the magnetic properties, mechanical properties, friction and wear properties, and corrosion resistance of the coating were investigated. The research results indicate that adding 6 wt% of boron to cobalt alloy in a 35 mT alternating magnetic field is beneficial for refining the microstructure, which can improve the mechanical properties of the coating. This research also discusses the effect of boron content on the wear and corrosion resistance of the coating. The results show that adding boron content enhances the magnetostrictive effect, and reduces the elastic modulus of the laser metal deposition coating while ensuring its hardness, thereby improving the wear and corrosion resistance of the laser metal deposition layer. The hardness of the coating can reach 1215 HV. The friction coefficient and corrosion current density of the coating are reduced by 26.9% and 60.2% respectively compared with the substrate. This work can help promote the application of laser metal deposition technology, reduce costs, and ensure performance.

Overview of piezoelectric energy harvester based on wind-induced vibration effect

In the field of new environmental energy harvesting technology, wind energy and piezoelectric energy harvesting have become research hotspots. By utilizing wind energy into vibration energy, i.e., wind-induced vibration effect is a research hotspot in the field of environmental energy harvesting. This article comprehensively analyzes the research status and development trend of piezoelectric energy harvesters based on wind-induced vibration effects at home and abroad. It was found that the conversion process of wind energy to vibration energy is mainly based on flutter, galloping, and acoustic resonance. The conversion of vibration energy into electrical energy is mainly piezoelectric power generation, supplemented by magnetic induction power generation and friction power generation. For high power density and small volume application scenarios, resonant cavity type wind vibration energy collection is the main development trend.

A semi-analytical approach for two-dimensional frictional contact of anisotropic magneto-electro-elastic solids

In this work, we present a semi-analytical modeling approach for solving the frictional contact of two-dimensional anisotropic magneto-electro-elastic (MEE) solids. The method is established in a broad framework in which the contact body is made of generally anisotropic MEE materials, the punch head can be arbitrary, and the punch can be subjected to generalized loading conditions including mechanical forces and electric and magnetic charges. An analytical solution of generalized distributed load along the half-plane surface is derived and utilized to formulate the semi-analytical equations governing the relation between the generalized displacements and tractions. Based upon the semi-analytical equations, the semi-analytical model in which the influence matrices can be calculated explicitly and its effectiveness is established. An iterative procedure is then used for determining the contact region, contact status, generalized surface deformation and the distribution of contact tractions, as well as the punch’s indentation depth and electric and magnetic potentials. The present approach is verified by comparing its numerical results with those obtained by the existing analytical solutions and boundary element method. The influences of different factors, such as punch profile, mechanical load, electric and magnetic charges, friction coefficient and material properties, are also analyzed. The capability of this method to handle complicated geometry, such as rough surfaces, is finally discussed, showing the potential performance of the developed method for practical engineering applications.

Transition between the stick and slip states in a simplified model of magnetic friction.

We introduce a simplified model of magnetic friction and investigate its behavior using both numerical and analytical methods. When resistance coefficient γ is large, the movement of the system obeys the thermally activated process. In contrast, when γ is sufficiently small, the slip and stick states behave as separate metastable states, and the lattice velocity depends on the probability that the slip state appears. We evaluate the velocities in both cases using several approximations and compare the results with those of numerical simulations.

Fractional Maxwell viscoelastic model to explain dynamic magneto-viscoelastic properties of an isotropic magnetorheological elastomer containing flake-shaped magnetic particles

ABSTRACT A modified fractional Maxwell viscoelastic model was developed for the dynamic magneto-viscoelastic behavior of an isotropic magnetorheological elastomer (MRE) having flake-shaped iron particles. This model can capture the low-frequency and high magnetic field static friction contribution with frequency, both in storage and loss modulus. The magnetic dipole-dipole interaction model is used to find the influence of the external magnetic field on viscoelastic behavior. The variation of field-induced modulus with the magnetic field is well described using the Langevin function. The predicted and experimental measured storage and loss modulus agree with the present model with an accuracy of ≥99%. The present model is compared with the results of spherical particle-based MRE.

Sealing performance in a spiral groove mechanical seal lubricated by magnetic fluid

PurposeMagnetic fluid has excellent function used as lubricants in bearings and mechanical seals, and the purpose of this study is to investigate the sealing performance in a spiral groove mechanical seal lubricated by magnetic fluid.Design/methodology/approachThe sealing characteristic parameters of the lubricating film between the end faces of two sealing rings were calculated based on the Muijderman narrow groove theory for a spiral groove mechanical seal lubricated by magnetic fluid. The film thickness was determined according to the balanced forces on the rotating ring, and the effects of operating conditions, intensity of the magnetic field and diameter of nanoparticles on the sealing characteristics were investigated.FindingsIt has been found that the intensity of magnetic field has a great effect on the viscosity of magnetic fluid, film thickness and friction torque while has a little effect on the mass flux of magnetic fluid. The film thickness, mass flux of magnetic fluid and friction torque increase with the increasing volume fraction, rotating speed and diameter of magnetic nanoparticles in magnetic fluid. The mass flux of magnetic fluid decrease with the increasing closing force, and the friction torque decreases with the increase of media pressure.Originality/valueThe change of intensity of magnetic field can affect the viscosity of magnetic fluid and then changes the sealing performance in a mechanical seal lubricated by magnetic fluid. To reduce the mass flux of magnetic fluid and friction torque, the volume fraction, diameter of solid magnetic particles and film thickness should be 5%–7%, 8–10 nm and 2–9.3 µm, respectively.Peer reviewThe peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-02-2023-0032/

Analysis of magnetohydrodynamic nanofluid flow over irregular boundaries of Riga plate with thermal radiation and suction/injection

The current study pivoted on the numerical simulation of magnetohydrodynamic nanofluid flow through the irregular boundary over the Riga plate with heat radiation, suction/injection. The governing equations of continuity, momentum, and energy are constructed to be nonlinear in nature, based on the current problem. The combination of Quasilinear technique with finite difference method using irregular boundaries has been used to solve the governing equations. The velocity profile is enhanced for incremented values of Hartman number. The thermal radiation parameter due to Rosseland approximations is enhanced for temperature and concentration profiles whereas it declines the heat transfer and mass transfer profiles. Temperature, concentration, and heat transfer rates increase for augmented magnetic parameter values, but velocity and skin friction coefficient profiles show the opposite behaviour. The enhanced values of Biot number along with suction/injection parameter reduces the values of skin friction coefficient. The radiation parameter helps to drop the energy rate in the fluid flow as it reduced the skin friction coefficient values. The upsurged values of the thermal radiation parameter along with electromagnetic parameter decreases the values of the Nusselt number.

Analysis of free and forced convections in the flow of radiative viscous fluid with oxytactic microorganisms

The prime intend behind the current effort is to explicate flow attributes of magnetically influenced Newtonian fluids toward a stretchable sheet under the novel physical impact of oxytactic microorganisms in a comparative manner for free and forced convections. In addition, modified Fourier and Fick’s laws are implemented to examine the change in temperature and concentration distributions in a more realistic manner by accounting thermal and mass relaxation parameters in the flow. The obtained PDEs are reduced into the non-linear ODEs by employing similarity variables. Due to the complexity of parametrically based differential equations, a numerical scheme based on a finite-difference approach is implemented via the MATLAB built-in routine known as BVP4C. Flow-controlling parameter effects on associated distributions are evaluated through graphs and tables. Subsequently, the influence of flow-controlling parameters on associated distributions is revealed through pictures in a comparative manner for different convection regimes. Additionally, the quantities such as heat and mass fluxes along with the density of motile microorganisms are also illustrated. From the thorough analysis of the current investigation, it is inferred that velocity distribution enhances for free and forced convections, whereas the temperature of the fluid diminishes against the mentioned convective regimes. It is manifested that the Nusselt number is more in the situation of free convection instead of the forced convection situation. The magnitude of the skin friction factor is more in case of free convection as compared to the forced convection regime. It is also reported that by uplifting the magnitudes of concentration and thermal relaxation parameters, depreciation in associated heat and mass transfer rate arises. In addition, it is also reported that with the increment in the magnetic field, buoyancy ratio, bioconvection parameters, and Rayleigh number skin friction accelerate, while the behavior is quite opposite in case of stretching the ratio parameter.

Impact of an Induced Magnetic Field on the Stagnation-Point Flow of a Water-Based Graphene Oxide Nanoparticle over a Movable Surface with Homogeneous–Heterogeneous and Chemical Reactions

Water has attracted plenty of attention as a lubricant for manufacturing due to the fact that it is inexpensive, environmentally friendly, and efficient. Because of their outstanding mechanical capabilities, water dispensability, and range of real applications, graphene oxide (GO) materials have the potential to augment the effectiveness of water lubrication. With this encouragement, we inspect the impact of induced magnetism on the fluid flow near a stagnation point dispended with water-based GO nanoparticles caused by a movable surface with a homogeneous–heterogeneous chemical reaction. The leading equations and their related boundary constraints are first transformed into a non-dimensional form through the utilization of the similarity technique. The consequent equations are then numerically solved by employing the bvp4c scheme. Those figures are used to exemplify the stimulation of the relevant constraints on the fluid flow, induced magnetic profiles, temperature profiles, concentration profiles, heat transfer, and friction factor. It is observed that the nanoparticle’s volume fraction enhances the heat transfer rate, as well as the friction factor. The heat transfer and friction factor escalate by almost 11.71% and 0.96% for the respective upper-branch solutions due to the larger impacts of nanoparticles’ volume fractions, while for the lower-branch solutions, they are augmented at about 21.8% and 0.66%, respectively. In addition, double solutions can be found in the limited values of a movable parameter.

A Single-Joint Worm-like Robot Inspired by Geomagnetic Navigation

Inspired by identifying directions through the geomagnetic field for migrating birds, in this work, we proposed and fabricated a single-joint worm-like robot with a centimeter scale, the motion of which could be easily guided by a magnet. The robot consists of a pneumatic deformable bellow and a permanent magnet fixed in the bellow’s head that will generate magnetic force and friction. Firstly, in order to clarify the actuating mechanism, we derived the relationship between the elongation of the bellows and the air pressure through the Yeoh constitutive model, which was utilized to optimize the structural parameters of the bellow. Then the casting method is introduced to fabricate the silicone bellow with a size of 20 mm in diameter and 28 mm in length. The manufacturing error of the bellow was evaluated by 3D laser scanning technology. Thereafter, the robot’s moving posture was analyzed by considering the force and corresponding motion state, and the analysis model was established by mechanics theory. The experimental results show that the worm-like robot’s maximum speed can reach 9.6 mm/s on the cardboard. Meanwhile, it exhibits excellent environmental adaptability that can move in pipelines with a diameter of 21 mm, 32 mm, 40 mm, and 50 mm, and surfaces with different roughness. Moreover, the robot’s motion was successfully guided under the presence of the magnetic field, which shows great potential for pipeline detection applications.

Squeezing Flow between Two Parallel Plates under the Effects of Maxwell Equation and Viscous Dissipation

The unsteady, incompressible electroviscous fluid flow has been investigated with thermal energy transmission across two parallel plates. The upper plate is in motion, while the lower one is stationary. The flow is governed by the Navier-Stokes equations, which are combined with the Maxwell equation. The system of nonlinear PDEs is simplified to a system of ODEs along with their boundary conditions using Von-Karman's transformation. For the problem's analytic solution, the homotopy analysis method (HAM) has been used, and the result is compared to the Runge Kutta method of order four and latest computational technique parametric continuation method (PCM) to determine the validity of the scheme. It has been noted that the outcome is reflected with the best settlement. Interest physical constraints are graphically illustrated and briefly discussed in relation to velocity, temperature, magnetic strength profile, skin friction, and Nusselt numbers. The axial velocity of the fluid reduces by the action of Reynold numbers R1. The magnetic profile intensity is reduced as the Batchelor number rises, while the magnetic strength is boosted as the magnetic Reynolds number R3 increases.

Numerical investigation on effects of induced magnetic field and viscous dissipation on MHD mixed convection in a vertical micro porous channel using Brinkmann – Forchheimer extended Darcy model

Impact of viscous dissipation and induced magnetic field in Brinkmann- Forchheimer extended Darcy flow of MHD mixed convectionsin a vertical microporous channel is investigated. Three different viscous dissipation models along with three different wall ambient temperature difference ratios are analysed. Projected results evidently indicate that the kind of viscous dissipation model has a notable impact on velocity distribution, induced magnetic field, current density, skin friction, and Nusselt number. It is found that an increase in Brinkman number increases velocity in the channel for distinct values of wall ambient temperatures difference ratios. Due to the domination of convection, an increase in Darcy number increases skin friction. The effect of induced current density on Darcy number, Brinkmann number, and inertial parameters are also discussed. The CFD data is used to train the built ANN model for predicting the heat transfer characteristics in the considered channel with 98.96% accuracy.

Light diffraction in rotating magnetic emulsions in a magnetic field

The light diffraction in magnetic emulsions with droplets of a kerosene based magnetic fluid in AMG-10 hydraulic oil under the influence of magnetic and hydrodynamic fields has been studied experimentally. Rotation of the emulsion sample in a uniform magnetic field revealed a deflection of the diffraction pattern by a certain angle. An interpretation of the effect based on the anomalous diffraction approximation is proposed. The rotation of the diffraction pattern in the field of hydrodynamic forces is interpreted based on the balance of the torques of magnetic and viscous friction forces acting on an elongated droplet of magnetic fluid.

RETRACTED: Computational analysis of ohmic and viscous dissipation effects on MHD mixed convection flow in a vertical channel with linearly varying wall temperatures

An analysis is carried out to investigate magnetohydrodynamic flow in a vertical channel formed by electrically conducting and non – conducting walls taking into account the effect of induced magnetic field. The phenomenon of heat transfer is also examined subject to the viscous and ohmic dissipations. The temperature of the channel wall increases or decreases linearly with x as [Formula: see text] in the direction of the fluid flow. The solutions are obtained analytically by perturbation method and numerically by finite element method. The solution is found to be dependent on the governing parameters which includes the Hartmann number, Rayleigh number, Brinkmann number, magnetic Prandtl number, and Reynolds number. The velocity, temperature, induced magnetic field, Nusselt number, and skin friction are evaluated for several set of values of these parameters. Increasing Brinkmann number augments both velocity and temperature profiles. Results reveal that the impact of Hartmann number and magnetic Prandtl number on the induced current density represents decreasing nature at the central region of the channel. The obtained velocity profile depicts inflection points for [Formula: see text] and the inflection points move towards the walls as the Rayleigh number enhances. Skin friction enhances with reference to Hartmann and magnetic Prandtl number at the wall [Formula: see text] while the reverse trend is observed at the wall [Formula: see text]. Effect of Rayleigh number and Brinkmann number on Nusselt number is also studied at the walls. This research combines computational fluid dynamic (CFD) simulations and artificial neural network (ANN) analysis. It is noted that the predicted data specified by the ANN model is in good agreement with the computed values of [Formula: see text] The average relative error in [Formula: see text] prediction is around [Formula: see text].

Design and Control of Multi-Plate MR Clutch Featuring Friction and Magnetic Field Control Modes.

A magnetorheological (MR) multi-plate clutch was proposed with both mechanical friction mode and magnetic field control modes. The magnetic field control mode was based on an MR fluid coupler that changed its viscous properties according to the density of an applied magnetic field. This mode was used in the early stage of clutch operation to reduce the impact of friction between the disc and plate, and eliminate to the extent possible the difference in their relative speeds when contacting each other in later stages. Once the rotational speed difference between the disc and plate was reduced, the clutch was operated in mechanical friction mode by compressing the friction surfaces together. A torque modeling equation was then derived for each mode based on the Bingham model of the MR fluid, and the transmission torque of the proposed multi-plate clutch was derived using these equations as well as magnetic field analysis results obtained using ANSYS Maxwell. A multi-plate MR clutch was then fabricated, and its torque transmission characteristics were evaluated in the magnetic field control and mechanical friction modes. The results confirmed that the model-based torque calculations were consistent with the observed transmission torque. Finally, control algorithms for mechanical friction only and mixed mechanical friction/magnetic field control torque tracking of the proposed MR multi-plate clutch were designed, and their performances were evaluated when applying unit step command, half-sine-wave command, and rotational speed changes. The results indicated that the torque tracking control was performed smoothly, demonstrating the advantages of the proposed clutch.

Advanced application of stimuli-responsive drug delivery system for inflammatory arthritis treatment.

Inflammatory arthritis is a major cause of disability in the elderly. This condition causes joint pain, loss of function, and deterioration of quality of life, mainly due to osteoarthritis (OA) and rheumatoid arthritis (RA). Currently, available treatment options for inflammatory arthritis include anti-inflammatory medications administered via oral, topical, or intra-articular routes, surgery, and physical rehabilitation. Novel alternative approaches to managing inflammatory arthritis, so far, remain the grand challenge owing to catastrophic financial burden and insignificant therapeutic benefit. In the view of non-targeted systemic cytotoxicity and limited bioavailability of drug therapies, a major concern is to establish stimuli-responsive drug delivery systems using nanomaterials with on-off switching potential for biomedical applications. This review summarizes the advanced applications of triggerable nanomaterials dependent on various internal stimuli (including reduction-oxidation (redox), pH, and enzymes) and external stimuli (including temperature, ultrasound (US), magnetic, photo, voltage, and mechanical friction). The review also explores the progress and challenges with the use of stimuli-responsive nanomaterials to manage inflammatory arthritis based on pathological changes, including cartilage degeneration, synovitis, and subchondral bone destruction. Exposure to appropriate stimuli induced by such histopathological alterations can trigger the release of therapeutic medications, imperative in the joint-targeted treatment of inflammatory arthritis.

Novel sodalite stabilized zero-valent iron for super stable and outstanding efficiency in activating persulfate for organic pollutants fast removal

In this study, novel porous sodalite (SOD) was synthesized through Reactive Oxidation Species (ROS) route from industrial waste lithium silicon fume (LSF) to stabilize nZVI (SOD@nZVI), and used as an outstanding persulfate (PS) activator for efficient organic degradation. Characterization results revealed nZVI evenly distributed on SOD via ion-exchange, and the fabricated SOD@nZVI exhibited high stability and superior reactivity over a wide pH range of 2–12 during oxidation reaction. The mechanism responsible for fast organic degradation in the SOD@nZVI+PS system was carefully investigated, and weak magnetic field (WMF) and friction were found to contribute to improved SOD@nZVI performance. The fast redox cycle of Fe2+/Fe3+ on SOD@nZVI can be stimulated by changing the mixing condition and altering the friction layer to harvest mechanical energy during the reaction, which can maximum persulfate activation to generate more reactive radicals for organic fast degradation. This study is of great significance, as it offers a practical route turning waste into excellent PS activator for in-situ organic pollution remediation, as well as proposing a new idea to maximum PS activation performance by manipulating the inner lining of reactor.

Preparation process optimization of hard magnetic brake friction material based on NdFeB additive

PurposeThis study aims to develop magnetic field-controlled friction braking technology, the preparation process of hard magnetic brake friction material was optimized and analyzed in this paper.Design/methodology/approachNdFeB, a rigid magnetic material, was selected as additive. Magnetic field orientation, a part of material preparation, was added to the preparation process. Experiments investigated the tribological properties of each brake lining sample. The preparation process of the hard magnetic friction material was optimized based on fuzzy theory by using analytic hierarchy process (AHP) methods and SPSS software. The microscopic morphology and the distribution and content of elements of friction lining samples prepared with or without orientation excitation voltage were analyzed by scanning electron microscope and energy dispersive X-ray microanalysis.FindingsThe results showed that the tribological properties of brake lining samples could be improved by process optimization and the oriented excitation voltage can effectively improve the properties of the brake lining.Originality/valueThe magnetic field orientation was added into the traditional preparation process, and a set of process parameters with the best tribological properties were obtained through optimization. It is believed that this research will be of great theoretical and practical significance to develop both new brake materials and active control technology of the braking process in the future.