Neodymium Permanent Magnet Research Articles

Static Magnetic Field Focusing With Neodymium Magnets For Wound Healing: A Numerical Study

Static magnetic fields (SMFs) find widespread applications in diverse scientific, technological, and medical domains. This study explores the potential of neodymium permanent magnets in focusing and controlling SMFs, specifically emphasizing wound healing applications. Numerical simulations using COMSOL Multiphysics create a uniform static magnetic field for wound healing. The study systematically increases the number of neodymium magnets, demonstrating enhanced magnetic flux density and a focused magnetic field. The results affirm the efficacy of neodymium magnets in generating a uniform static magnetic field between 160-600 m Tesla. This research proposes neodymium permanent magnets as a promising tool for wound healing applications, offering a non-invasive and focused therapeutic approach. While the study provides valuable insights, further experimental and clinical validations are necessary to establish the real-world efficacy of this method. The work contributes to the evolving understanding of static magnetic fields as a viable therapeutic modality for various medical conditions, particularly in the context of wound healing.

Modified free energy generation using permanent Neodymium Magnet based on Bedini with Maxwell and Lorenz gauge conditions

An efficient, reliable, and real-time electricity generator is proposed by keeping in view the constraints, related to the electricity generation cost, resource reservoirs, greenhouse gas emission, energy storage, and power demand for a pre-defined residential area. Paramount importance is given to the rotor's design; coupled with movable neodymium magnets to increase the harvester's life span and system's net revenue. For the amplification in the stator output, a cost-effective approach is adopted that is based on the parallel winding of the bifilar coil. Furthermore, the coefficient of performance factor for the Bedini's smart school girl circuit based electricity harvester is modified by aiding the concepts of radiant energy incorporated with the electromagnetic phenomenon. Moreover, the mathematical model is formulated by the Maxwell equations using the Lorenz gauge condition to capture free vacuum energy from the environment. For the investigation, analysis, and corroboration of the proposed design, results are reported after performing extensive numerical computations and a comprehensive comparison between the original and modified design is stated in detail.

Design and Construction of a 3-Phase Axial Type BLDC Generator for PLTB

The need for electrical energy in remote areas to improve community welfare must be a concern for universities. The government's ability to build new electricity sources is very minimal because it requires large infrastructure and costs, but the government continues to strive to develop new power plants. Therefore, it is necessary to strive for innovation to build power plants from renewable energy sources. There is a need to use renewable energy as an alternative to replace electrical energy which is increasingly in crisis. One alternative energy that is easy to make is energy that uses magnetic force as a model for generating electricity. Brushless Direct Current (BLDC) motors are an alternative to current DC motors. This three-phase permanent magnet axial flux generator is specially designed for vertical-type wind turbines. This generator consists of two stators and one rotor. where each stator consists of 9 coils and the magnet used is a neodymium permanent magnet. Based on test results, this generator can produce a voltage of 12.57 VDC with a wind speed of 6.84 m/s. So, it can turn on DC lights and charge DC batteries. This three-phase axial BLDC generator was tested in 3 stages, namely without load, using battery load, and DC-light load with wind conditions depending on natural conditions.

Advancing Neodymium Permanent Magnets with Laser Powder Bed Fusion Technology: A Comprehensive Review of Process-structure-property Relationship

This comprehensive review article thoroughly examines the promising prospects of utilizing laser powder bed fusion (LPBF) technology in the manufacturing of neodymium (NdFeB) permanent magnets (PM). Providing an in-depth analysis,...

A study on performance evaluation of hybrid dampers

In this study, the experimental performance evaluation of the hybrid damper with an innovative structure was performed as a preceding study to apply the self-centering braced frame to the structure. Hybrid dampers used a structural novel material with recovery and semi-permanent characteristics to recenter the displacement caused by external loads. Structural novel materials were used polyurethane and superelastic shape memory alloy(SSMA), which provide recentering capacity through recovery properties, and neodymium permanent magnets, which enhance energy dissipation through friction properties. SSMA could recover the displacement generated at room temperature due to shape memory effect and superelastic behavior, and initial compression was applied to polyurethane to give recovery. In order for each material to play a role appropriate for its purpose, the hybrid damper was designed so that SSMA was applied in tension, polyurethane in compression, and neodymium permanent magnet in friction. In addition, a structural experiment was conducted on the damper by setting the design variables to the initial compression of polyurethane and the presence or absence of neodymium permanent magnet. As a result of analyzing the maximum force, residual displacement, recentering force, and energy dissipation capacity for the behavior response derived from experiments on each model, the model that included all three new structural materials and applied the largest initial compression showed the best performance. Therefore, it is expected that the development of a self-centering braced frame will be possible if a hybrid damper is applied as a result of performance evaluation through structural experiment.

Numerical and experimental study of influence function in magnetorheological finishing (MRF) of freeform surface

In the present work, a dynamic viscosity model is proposed based on the varying magnetic flux density of the neodymium permanent magnet along its width. The proposed viscosity model is helpful in analysing the influence function in a better way as compared to standard non-Newtonian fluid models. During the finishing process, the research of influence function aids in establishing the right range of process parameters. MR fluid flow on the freeform surface is examined numerically and experimentally to better understand the influence function. The flow behaviour of the MR fluid is investigated using the three-dimensional (3D) computational fluid dynamics (CFD) simulation, wall shear stress and dynamic pressure are estimated on the Oxygen-free high conductivity (OFHC) copper for various process parameters (working gap and rotational speed). On the convex and concave sections of a freeform surface, indentation depth is estimated for various process parameters using the results of dynamic pressure and empirical relation. Finishing tests are performed to investigate forces (tangential and normal) and indentation depth on the workpiece, and the results are evaluated.

Effect of NdCoGa alloy addition to waste wind turbine magnets to enhance the characteristics of recycled sintered NdFeB permanent magnets

Neodymium (NdFeB) permanent magnets play a key role in motors and other devices, and are important to both defense and civilian industrial uses; however, due to the limited rare earth resources, the issue of recycling waste NdFeB magnets to achieve sustainable development has attracted much attention. An innovative and valid method for the recycling of waste NdFeB magnets is demonstrated in this study. Recycled sintered NdFeB permanent magnets were prepared on a large scale up to 100 kg per batch by adding NdCoGa ternary rare earth alloy to waste wind turbine NdFeB magnets, and their magnetic properties, corrosion resistance and high temperature aging characteristics were evaluated. The recycled magnets were manufactured by mixing waste magnets A, B, and NdCoGa alloy according to weight percentage ratio of 90:7:3 respectively. Through BH Curve measurement and FE-EPMA qualitative element analysis, the differences in the magnetic properties and microstructure before and after adding the NdCoGa elements were observed. The results show that the magnetic properties of waste magnet A are Br = 12.60 kG, iHc = 18.92 kOe and (BH)max = 39.19 MGOe; the magnetic properties of waste magnet B are Br = 12.77 kG, iHc = 18.15 kOe and (BH)max = 40.25 MGOe. In contrast, the magnetic properties of the recycled magnets prepared in this study are Br = 12.63 kG, iHc = 18.72 kOe, and (BH)max = 39.95 MGOe, indicating that the proposed process restores the magnetic properties of the recycled magnets to the level of the original waste magnet. Also, a brand new commercial N40H magnet is further used as a control group, where the corrosion resistance and high temperature aging characteristics of bare materials were evaluated by Pressure Cooker Test (PCT), and oven/flux meter respectively. The results show that the average corrosion weights per unit area are 0.89 mg/cm2 and 1.23 mg/cm2, as well as the demagnetization rate of the high temperature aging is less than 0.4%. Compared with the new magnet, the recycled magnet has the same level of high temperature aging resistance, and 28% higher corrosion resistance. As a result, adding only 3% NdCoGa alloy to the waste magnet is beneficial to restore the magnetic properties and high temperature aging resistance, up to the level of new magnets, and also greatly enhances its corrosion resistance and reduces the cost of magnet remanufacturing. This result indicates that the recycled NdFeB permanent magnets developed in this research are more suitable for offshore wind turbine generators and electric vehicle motors operating at high temperatures and high humidity for a long period of time.

Permanent neodymium magnets in the Russian wind power industry

This article is devoted to the problems of wind energy in Russia. One of the key issues in the development of wind energy in our country is the uninterrupted supply of permanent neodymium magnets and raw materials for their manufacture to wind generator manufacturers. After the collapse of the Soviet Union, several enterprises with the necessary competencies and technological equipment to produce magnets based on rare earth metals (REMs) survived in the country. However, the problem is that Russia does not have a complete production chain to the level of oxides, as well as individual rare earth elements and alloys based on them. All permanent magnets based on rare earth metals are imported, and supply interruptions negatively affect the work of high-tech companies, as well as enterprises of the fuel and energy complex and the military–industrial complex. The article analyzes the need of the country's wind energy industry for permanent neodymium magnets, the full production cycle of which can become one of the incentives to restore the production chain of rare earth metals and products based on them.

原子論的スピンモデルによる永久磁石の磁気特性の研究 ―熱揺らぎおよび温度効果の取り扱いと将来展望―

We review atomistic spin model studies, a new approach for theoretical investigations, on magnetic properties of permanent magnets. In the atomistic modeling, the microscopic details of magnetic parameters and lattice structures are realistically considered, and the temperature effect, including thermal fluctuation, is properly treated based on statistical physics methods: Monte Caro methods and stochastic Landau-Lifshitz-Gilbert equation methods. We introduce how to treat thermal effects for static and dynamical properties using these methods. Focusing especially on neodymium permanent magnets, we discuss features of magnetization, domain wall, coercivity of a grain, nucleation and pinning fields, and dysprosium substitution effect, which were first elucidated with those methods.

Dzyaloshinskii–Moriya interactions in Nd2Fe14B as the origin of spin reorientation and the rotating magnetocaloric effect

In this study, the mechanism of spin reorientation in Nd2Fe14B, which is the host crystal of prevalently employed neodymium permanent magnets, was investigated by combining first–principles calculations and Monte Carlo simulations. Spin reorientation is thought to originate from crystal field effects and has not received significant attention from researchers because it is an undesirable property in hard magnet applications. Similarly, Dzyaloshinskii–Moriya interactions are often ignored in rare–earth bulk systems, including permanent magnets such as Nd2Fe14B, because it is believed that magnetic anisotropy is more dominant than Dzyaloshinskii–Moriya interactions. However, in this study, for the first time, we found that the spin reorientation in Nd2Fe14B is caused by Dzyaloshinskii–Moriya interactions. Furthermore, we found that the spin reorientation in Nd2Fe14B results in the rotating magnetocaloric effect, which might be used for practical applications. We also found that the Dzyaloshinskii–Moriya interactions non-negligibly affect the physical properties of magnetic materials.

Magnetic field hydrocooling system: Effect of field intensities on the cooling characteristics of three different leavy vegetables

The physiological changes occurring during postharvest of leafy vegetables affect quality. To address this, several cooling technologies that utilize physical fields like magnetic fields (MFs) have been proposed. The application of MFs in the cooling of leafy vegetables however remains a substantial controversy among the food engineers. Therefore, the effectiveness should be clarified by experiments. In the current study, the effect of MFs (at 534.1 mT, 458.0 mT, and 396.8 mT) on hydrocooling process of three different leafy vegetables including jute mallow, fluted pumpkin, and bitter leaf was investigated by using a specially designed hydrocooling system facilitated with magnetic field (also known as magnetic field hydrocooling; MFHC) generated from a Neodymium permanent magnet. The investigation included the comparison of the cooling curves, physiological loss in weight (PLW), microbial loads, and observation of microstructures. Based on the results of the experiment, it was observed that the weak magnetic fields provided significant improvement on the hydrocooling technique as well as the quality of hydrocooled vegetables. The MFHC assisted by Neodymium magnet (at 396.8 mT) provided higher cooling rate (at P ≤ 0.05) when compared with conventional room cooling, reduced microbial loads significantly from 8.40 × 105 to 5.86 × 105 CFU/ml, 7.03 × 105 to 5.89 × 105 CFU/ml and 6.00 × 105 to 4.0 × 105 CFU/ml (at P ≤ 0.05) for jute mallow, fluted pumpkin and bitter leaf respectively. In addition, hydrocooling-assisted by magnetic field (at 396.8 mT) is more effective in the preservation of the microstructures. The study indicates that the MFHC technology enhances cooling process and preserves the leafy vegetables, thus pose great potential in the food industry. Practical applicationsLeafy vegetables deteriorate faster after harvest; hence, there is a need to cool them in order to extend their shelf-life. MFHC technique has great potentials in preservation of leaves, with the advantage of minimum quality loss due to reduction in cooling time and microbial activities. Currently, innovative studies have been carried out on the use of MFHC technique to improve the cooling process and achieve better quality preservation. However, the findings presented in this work can provide detail insights on the quality of some leafy vegetables that were cooled by MFHC, and give some guidance for further developments of MFHC technology.

Separation of Neodymium (III) and Lanthanum (III) via a Flat Sheet-Supported Liquid Membrane with Different Extractant-Acid Systems.

The increasing demand for neodymium (Nd) permanent magnets in electric motors has revived research interest of Nd recovery and separation from other rare earth elements (REEs). Typically, Nd/La separation is necessary for Nd recovery from primary ores and secondary resource recycling. This research used a flat sheet-supported liquid membrane (FSSLM) with different extractant-acid systems to extract Nd from a Nd/La mixture. The recovery and separation of Nd/La with 204P-H2SO4, 507P-HCl, and TBP-HNO3 were discussed. The results showed effective Nd recovery and promising Nd/La selectivity could be achieved in the 507P-HCl system, compared to 204P-H2SO4 and TBP-HNO3. The addition of citric acid to the feed solution was effective for pH buffering but did not improve the Nd transport or Nd/La selectivity. Long-term stability of the 507P-HCl extractant system was demonstrated by extending the processing time from 6 h to 6 days.

A Thermal and Electro-Magnetic Hybrid MOEMS Microscanner With Integrated Spatial Light Modulation and Metalens for Resolution Enhancement of Infrared Imaging Systems

This article describes the development of a novel integrated thermal and electromagnetic hybrid microoptoelectro mechanical system (MOEMS)-based scanning actuator. Determining the optical architecture and components used for scanning are significant points of the study. A metalens and a coded mask, both of which can be produced by microfabrication methods, are used in the optical part of the actuator. In this context, a metalens consisting of nanoholes was designed and fabricated as the first alternative. Second, a specific coded mask was designed and applied to the center of the MOEMS structure for obtaining spatial light modulation. Captured scene images including the coded mask are processed and reconstructed by using the compressive sensing image processing algorithms. Silicon-on-insulator (SOI) is the substrate of structure and deep reactive ion and wet etching methods were used to fabricate the integrated actuator. To increase the optical transmission, the optically transmissive coded mask zone was coated with antireflective coating at the midwave infrared band. The magnetic field for obtaining Lorentz force on the actuators was achieved by using the neodymium permanent magnet located beneath the structure.

Magnetic Forces by Permanent Magnets to Manipulate Magnetoresponsive Particles in Drug-Targeting Applications.

This study presents preliminary computational and experimental findings on two alternative permanent magnet configurations helpful for magnetic drug administration in vivo. A numerical simulation and a direct experimental measurement of the magnetic induction on the magnet system's surface were used to map the magnetic field. In addition, the ferrite-type (grade Y35) and permanent neodymium magnets (grade N52) to produce powerful magnetic forces were also examined analytically and quantitatively. Ansys-Maxwell software and Finite Element Method Magnetism (FEMM) version 4.2 were used for all numerical computations in the current investigation. For both magnets, the generated magnetic fields were comparatively studied for targeting Fe particles having a diameter of 6 μm. The following findings were drawn from the present investigation: (i) the particle deposition on the vessel wall is greatly influenced by the intensity of the magnetic field, the magnet type, the magnet size, and the magnetic characteristics of the micro-sized magnetic particles (MSMPs); (ii) ferrite-type magnets might be employed to deliver magnetoresponsive particles to a target location, even if they are less powerful than neodymium magnets; and (iii) the results from the Computational Fluid Dynamics( CFD) models agree well with the measured magnetic field induction, magnetic field strength, and their fluctuation with the distance from the magnet surface.

Measuring and Modeling the Force between Permanent Magnets

In a 1993 book review, E. Pearlstein asks, “Why don’t textbook authors begin their discussion of magnetism by talking about magnets? That’s what students have experience with.” A similar question can be asked, “Why don’t professors have students measure the force between permanent magnets in introductory physics labs?” The answer to both questions may be the same. There is no simple equation describing the force between two permanent magnets. Yet, this familiar magnetic phenomenon deserves investigation. This article presents a novel apparatus using 3D-printed parts for measuring the force between two small cylindrical neodymium permanent magnets as a function of their separation. Data collected using this apparatus is compared to two models, namely an ideal dipole–dipole interaction, and the force between parallel coaxial loops of current.

Microscopic origin of coercivity enhancement by dysprosium substitution into neodymium permanent magnets

Neodymium (Nd) magnets (${\mathrm{Nd}}_{2}{\mathrm{Fe}}_{14}\mathrm{B}$), known as the strongest permanent magnets, are indispensable in realizing high efficiency in energy conversion devices. To enhance their coercivity at high temperatures, the Nd component is substituted with dysprosium (Dy) in the commercial products of the magnet. Surface Dy-rich shells are considered important for enhancing coercivity. However, the underlying microscopic mechanism has not been studied based on atomistic theories. In this study, first, the features and mechanisms of the enhancement were studied using an atomistic model of the Nd magnet. Subsequently, the threshold field (coercive force) for magnetization reversal and the dynamical features at absolute zero and finite temperatures were investigated. The results show that a change from surface to bulk nucleation occurs when the number of substituted layers increases and the anisotropy energy of Dy is resistant to temperature increase, which significantly enhances coercivity, especially at high temperatures.

Comparative Thermal and Demagnetization Analysis of the PM Machines with Neodymium and Ferrite Magnets

This paper provides computer analysis and experiential investigation of the permanent magnet machines with neodymium and ferrite permanent magnets to discuss the feasibility of utilizing induction machines-oriented equipment for PM machine production. For this purpose, the machines are obtained by replacing the squirrel-cage rotor of the induction motor with the flux-focusing (tangential) and surface-mounted (radial) permanent magnet rotors. Electromechanical parameters of the machines as electromagnetic torque and output power are discussed and compared. The temperatures of the neodymium and ferrite magnets are also calculated at rated current, and short circuit scenarios and the performance of two different cooling systems in minimizing the temperature effect on the machines are investigated. Furthermore, the demagnetization of permanent magnets at various load conditions is also studied. Finally, the results of the computer modeling are validated by the physical prototypes of the machines. The characteristics of the electrical machines under study were calculated using the Simcenter MagNet and Simcenter MotorSolve software packages.

Project development of a precision installer for measuring inhomogeneous density of the solution in the process of automation of the technological software and hardware complex

A project of a precision installer for measuring the inhomogeneous density of the solution has been developed. This module is one of the key components of an automated program-controlled complex created for the encapsulation of cell transport systems. An analysis of existing methods for determining the values of viscosity and density shifts shows that optical measurement methods are the most appropriate for designing the precision installer due to their simplicity and reliability. Implementation of optical measurement is also due to the need to ensure sterility of analyzed material, as well as non-destructive testing of liquid. Using the ultrasound method requires immersion in liquid of transmitting element and receiver, which violates the principle of sterility. According to the results of measurements, it was found that the method of recording optical radiation can determine density distribution in the cuvette volume after centrifugation with a high degree of accuracy. The exact positioning of the needle for the selection of liquid has been achieved. A measuring optical module has been developed to determine the inhomogeneous density of the liquid. Accurate positioning of the carousel at given points by mounting permanent neodymium magnets in the base of cuvette compartments has been achieved. The simplification of measuring configuration by the exclusion of dispersive elements, filters and the monochromator significantly reduces the cost of measuring equipment and makes it easy to implement for solving such problems. The introduction of modern digital technologies into the project makes it possible to process signal packets from positioning sensors and through individual channels, which is especially important for automating measurement and positioning processes, taking into account sterility

Magnetic properties of PDMS embedded with strontium ferrite particles cured under different magnetic field configurations

Flexible materials embedded with hard magnetic particles have recently gained widespread recognition as small-scale actuators due to their capacity to be a rapid and precise shape-shifting material. Strontium ferrite (SrFe12O19) particles have been shown as a great candidate for such applications, since it is an inert hard magnetic material that, in contrast to barium ferrite and neodymium, is also biocompatible. The preparation of such material is done by mixing the magnetic particles into the uncured elastomer (polydimethylsiloxane (PDMS)), in liquid form, and then pouring the mixture in a mold for curing. If the samples are subjected to a magnetic field during the curing process, chains of particles are formed in the direction of the applied field, thus creating an easy axis in this same direction. The magnetic properties of such composite cannot yet be found in literature. In this study, we analyzed three concentrations of strontium ferrite particles in PDMS under three field configurations, resulting in 9 different samples. The concentrations used were 1:1, 2:1, and 4:1 ratios of PDMS to strontium ferrite per weight. All three types of samples were cured either in a zero magnetic field, or over the north pole of a neodymium permanent magnet, or over the side of said magnet. A biaxial vibrating sample magnetometer (VSM) was used to measure hysteresis curves parallel and perpendicular to the curing field. The samples cured in a field show a squareness ratio of up to 0.94 while the samples cured in zero field, only close to 0.5. The samples cured in a field show a magnetic anisotropy with an easy axis parallel to the curing field. Harvesting these modified properties, a mobile robot manufacturing method is proposed that bypasses the need of applying a high intensity magnetic field.

Electromagnetic Forces Effects of MHD Micropump on the Blood Movement

The magnetohydrodynamic pump is an attractive solution, in particular for biomedical applications. In an MHD pump, an electromagnetic force is created by the applied magnetic field, which causes the fluid movement. The main advantage of the MHD pump is there are no mobile (mechanical) parts and it can place directly on veins. The present paper deals with the blood behaviour in the MHD micropump. A neodymium permanent magnet is used for applying a magnetic field to the channel in the MHD micropump. The numerical study examines the influence of the channel dimensions, the flux magnetic density and the electrode potentials on the blood velocity. This micropump can be easily controlled by a low voltage source. The numerical simulation analysis for the adopted model was implemented in order to verify the micropump operation. The magnetic and electrical fields have a strong influence on blood velocity in the MHD micropump. Finite element modelling software was used for this process. The second objective of this work is the possibility to exploit the properties of this pump in hemodialysis to pump blood and cleaning fluid.