HEATING RATE PREDICTION FOR INDUCTION WELDING MAGNETIC SUSCEPTORS

2021 ◽  
Author(s):  
ROMAIN G. MARTIN ◽  
CHRISTER JOHANSSON ◽  
JASON R. TAVARES ◽  
MARTINE DUBÉ
Keyword(s):  
Magnetic Field ◽  
Heating Rate ◽  
Surface Area ◽  
Magnetic Particles ◽  
Eddy Currents ◽  
Field Amplitude ◽  
Hysteresis Curve ◽  
Heating Rates ◽  
Electrically Conductive ◽  
Thermoplastic Matrix

Induction welding involves generating heat by applying an oscillating magnetic field, which produces eddy currents and Joule losses in an electrically-conductive material or hysteresis losses in a magnetic material. Most applications rely on eddy currents generation as composites are often made of electrically-conductive carbon fibres. However, in other applications, heat can be produced by a magnetic susceptor located at the weld interface of the parts to be joined. Composite films of magnetic particles dispersed in a thermoplastic matrix can serve as magnetic susceptors. Magnetic particles selection relies on various parameters that must be thoroughly defined beforehand. Firstly, the applied magnetic field amplitude and frequency is calculated, based on the generated current and the induction coil geometry. Secondly, the thermoplastic matrix is characterized, mainly with DSC measurements, to define its processing window. Finally, the magnetic properties of the particles are measured – for instance using a vibrating sample magnetometer (VSM) – to obtain the hysteresis curve for the applied field. The enclosed surface area of the hysteresis curve (i.e. absorbed energy density) is critical, as low hysteresis materials (i.e. soft magnets) will not dissipate enough heat, while high hysteresis materials (i.e. hard magnets) cannot be fully exploited as the saturation hysteresis is not reached within the used field amplitude. A methodology to approximate the hysteresis enclosed surface area with limited data is proposed, helping to anticipate the heating rate of a susceptor candidate material. Based on these parameters, the theoretical heating rates of three magnetic susceptor materials (magnetic particles of iron, nickel and magnetite) for induction welding are calculated. They are verified experimentally by comparing with the hysteresis analysis and by measuring the temperature evolution of samples made of polypropylene containing the magnetic particles.

scholarly journals FERROMAGNETS WITH EDDY CURRENTS AND PINNING EFFECTS: THEIR THERMODYNAMICS AND ANALYSIS

2011 ◽  
Vol 21 (01) ◽  
pp. 29-55 ◽  
Author(s):  
TOMÁŠ ROUBÍČEK ◽  
GIUSEPPE TOMASSETTI
Keyword(s):  
Magnetic Field ◽  
Domain Wall ◽  
Parabolic Equations ◽  
Eddy Currents ◽  
Continuum Theory ◽  
Nonlinear Parabolic Equations ◽  
Electrically Conductive ◽  
Existence Of Weak Solutions ◽  
Nonlinear Parabolic ◽  
Domain Wall Pinning

Existence of weak solutions is proved for a system of nonlinear parabolic equations/inequalities describing evolution of magnetization, temperature, magnetic field, and electric field in electrically-conductive unsaturated ferromagnets. The system is derived from a recently-proposed thermodynamically-consistent continuum theory for the ferro/paramagnetic transition. Besides the standard viscous-like damping, dissipation due to eddy currents and domain-wall pinning is considered.

Surface Induction Hardening of Steels: Process Modelling and Numerical Simulation

2019 ◽  
Vol 813 ◽  
pp. 399-403 ◽  
Author(s):  
Fausto Tucci ◽  
Vitantonio Esperto ◽  
Rubino Felice ◽  
Pierpaolo Carlone
Keyword(s):  
Magnetic Field ◽  
Finite Element ◽  
Current Density ◽  
Eddy Currents ◽  
Induction Hardening ◽  
Element Model ◽  
Work Piece ◽  
Heating Rates ◽  
Steel Component ◽  
Joule Effect

Heat treatments are widely used in industry to improve the surface behavior of components exposed to external mechanical actions and, therefore, undergoing wear phenomena. If compared to the conventional thermal treatments, induction hardening is an interesting candidate solution when the effect should be limited to the surface without affecting the microstructure and properties at the material core. Furthermore, this solution is appealing considering energy saving and cost reduction. In this process, an intense electric alternating current flows through a conductive coil enveloping the component to be treated. Such current generates a magnetic field and, as a consequence, eddy currents arise in the conductive work-piece providing a heat generation by the Joule effect. Due to this mechanism, the induction heating is characterized by faster heating rates with respect to the heating in a hot furnace. On the other hand, the induction hardening process requires a more challenging control of the operative parameters, namely the current density and frequency and the coil advancing speed. Numerical modeling and simulation are recognized as a very useful tool to predicting the effects induced by a treatment, avoiding undesired insufficient- or over-heating. The present work deals with a finite element numerical approach to the simulation of an induction hardening treatment of a steel component. The model is based on the subsequent solution of two numerical submodels. Firstly, the electro-magnetic field generated by the current flowing through a coil surrounding the processing part is inferred solving the Maxwell governing equations. Then, the magnetic field is used as input load for the subsequent heat transfer transient finite element model. The influence of the current density and frequency as well as other processing parameters on the magnetic and thermal fields is discussed.

scholarly journals The effect of magnetic particles covering the droplets on the heating rate of Pickering emulsions in the AC magnetic field

2020 ◽  
Vol 320 ◽  
pp. 114388 ◽  
Author(s):  
Rafał Bielas ◽  
Tomasz Hornowski ◽  
Katarína Paulovičová ◽  
Michal Rajňák ◽  
Arkadiusz Józefczak
Keyword(s):  
Magnetic Field ◽  
Heating Rate ◽  
Magnetic Particles ◽  
Pickering Emulsions ◽  
Ac Magnetic Field

Gas-Phase Production of Multifunctional Composite Nanoparticles by Photoinduced Chemical Vapor Deposition

2010 ◽  
Author(s):  
Adam Boies ◽  
Pingyan Lei ◽  
Jeff Roberts ◽  
Steven Girshick
Keyword(s):  
Magnetic Field ◽  
Gas Phase ◽  
Magnetic Particles ◽  
Magnetic Force ◽  
Critical Size ◽  
Chemical Vapor ◽  
Electrically Conductive ◽  
Magnetic Resonance Imaging Mri ◽  
Phase Production ◽  
Pole Orientation

Nano-scale materials and devices allow for unique interactions that are not possible at larger scales. Magnetic particles below a critical size (∼10 nm) demonstrate distinctive behavior known as superparamagnetism, where particles do not exhibit any net magnetic force outside the presence of an external magnetic field. However, within an alternating magnetic field, as in a magnetic resonance imaging (MRI) machine, superparamagnetic particles give off heat as a result of Brownian and Nee´lian relaxation. Heat produced by the shifting pole orientation can raise the temperature of the tissue sufficient to cause cell death through necrosis or apoptosis [1]. Additionally, combinations of electrically conductive and insulating materials within a single nanoparticle give rise to surface plasmon resonance. The resonance of the plasmon absorption can be tuned based on the relative thicknesses of the two layers. These particles can be used to thermally ablate cancer cells if the resonance is tuned to absorb light from an infrared laser. The penetrating ability of the nanoparticles combined with their capacity to kill cells make them excellent candidates for treatment of conditions such as brain tumors and prostate cancer.

scholarly journals Effect of Heating Rate on the Photocatalytic Activity of Ag–TiO2 Nanocomposites by One-Step Process via Aerosol Routes

Catalysts ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 17
Author(s):  
Kusdianto Kusdianto ◽  
Meditha Hudandini ◽  
Dianping Jiang ◽  
Masaru Kubo ◽  
Manabu Shimada
Keyword(s):  
Photocatalytic Activity ◽  
Heating Rate ◽  
Surface Area ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Uv Light ◽  
Total Pore Volume ◽  
Nanocomposite Films ◽  
Heating Rates ◽  
One Step

Ag–TiO2 nanocomposite films, based of Ag and TiO2 nanoparticles, were fabricated in a one-step aerosol route employing the simultaneous plasma-enhanced chemical vapor deposition and physical vapor deposition systems. The as-fabricated films were subjected to different heating rates (3 to 60 °C/min) with a constant annealing temperature of 600 °C to observe the significant changes in the properties (e.g., nanoparticle size, crystalline size, crystallite phase, surface area) toward the photocatalytic performance. The photocatalytic activity was evaluated by the measurement of the degradation of a methylene blue aqueous solution under UV light irradiation, and the results revealed that it gradually increased with the increase in the heating rate, caused by the increased Brunauer–Emmett–Teller (BET) specific surface area and total pore volume.

scholarly journals The Theoretical Magnetization Hysteresis Curve of Nd-Fe-B Anisotropic Bonded Magnets

2011 ◽  
Vol 21 (3) ◽  
pp. 272
Author(s):  
Nguyen Van Khanh ◽  
Nguyen Van Vuong
Keyword(s):  
Magnetic Field ◽  
Magnetic Particles ◽  
Random Number ◽  
Effective Interaction ◽  
Random Number Generation ◽  
Hysteresis Curve ◽  
Generation Technique ◽  
Magnetization Hysteresis ◽  
Gaussian Statistics ◽  
Bonded Magnet

The theoretical magnetization hysteresis curve of Nd-Fe-B anisotropic bonded magnets is simulated using Jiles-Atherton model and random number generation technique. Gaussian statistics was used to assign magnetic particles to random values of magnetic field (H$_{ai}$) and effective interaction ($\alpha )$ parameters. The prospect of anisotropic bonded magnet is evaluated and discussed.

scholarly journals Numerical Approach for Computation of Electromagnetic Shielding

2013 ◽  
Vol 64 (4) ◽  
pp. 256-260
Author(s):  
Daniel Mayer ◽  
Bohuš Ulrych
Keyword(s):  
Magnetic Field ◽  
Eddy Currents ◽  
Numerical Approach ◽  
Time Variable ◽  
Magnetic Shielding ◽  
Real Problem ◽  
Electrically Conductive ◽  
Optimization Task ◽  
Active Shielding ◽  
Effective Design

Disturbing magnetic field (so-called magnetic smog) can be in certain areas suppressed by shielding jacket. Disturbing field is possible to be “lead away” from the shielded area with the use of jacket made of materials with high magnetic permeability (so-called passive shielding, or flux-entrapment shielding). If the disturbing field is time-variable, eddy currents are induced into electrically conductive jacket. Magnetic field generated by these eddy currents suppress the disturbing field (this is called active shielding, or lossy magnetic shielding). Both of these principles can be applied altogether (this is called combined shielding). Presented paper states numerical approach to shielding jacket design and is an introduction to following solution of a real problem of magnetic shielding when the disturbing magnetic field is space-time complicated. Effective design of the magnetic shielding should then be formulated as an optimization task.

Analysis of magneto rheological elastomers for energy harvesting systems

2020 ◽  
Vol 64 (1-4) ◽  
pp. 439-446
Author(s):  
Gildas Diguet ◽  
Gael Sebald ◽  
Masami Nakano ◽  
Mickaël Lallart ◽  
Jean-Yves Cavaillé
Keyword(s):  
Magnetic Field ◽  
Energy Harvesting ◽  
Shear Strain ◽  
Magnetic Induction ◽  
Magnetic Particles ◽  
Homogeneous Magnetic Field ◽  
Electrical Signal ◽  
Harvesting Systems ◽  
Dc Bias ◽  
Magneto Rheological

Magneto Rheological Elastomers (MREs) are composite materials based on an elastomer filled by magnetic particles. Anisotropic MRE can be easily manufactured by curing the material under homogeneous magnetic field which creates column of particles. The magnetic and elastic properties are actually coupled making these MREs suitable for energy conversion. From these remarkable properties, an energy harvesting device is considered through the application of a DC bias magnetic induction on two MREs as a metal piece is applying an AC shear strain on them. Such strain therefore changes the permeabilities of the elastomers, hence generating an AC magnetic induction which can be converted into AC electrical signal with the help of a coil. The device is simulated with a Finite Element Method software to examine the effect of the MRE parameters, the DC bias magnetic induction and applied shear strain (amplitude and frequency) on the resulting electrical signal.

scholarly journals Optical Imaging of Magnetic Particle Cluster Oscillation and Rotation in Glycerol

2021 ◽  
Vol 7 (5) ◽  
pp. 82
Author(s):  
River Gassen ◽  
Dennis Thompkins ◽  
Austin Routt ◽  
Philippe Jones ◽  
Meghan Smith ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Magnetic Particles ◽  
Magnetic Particle ◽  
Barium Hexaferrite ◽  
Optical Microscope ◽  
Simplified Model ◽  
Particle Cluster ◽  
Average Deviation ◽  
Cross Sectional

Magnetic particles have been evaluated for their biomedical applications as a drug delivery system to treat asthma and other lung diseases. In this study, ferromagnetic barium hexaferrite (BaFe12O19) and iron oxide (Fe3O4) particles were suspended in water or glycerol, as glycerol can be 1000 times more viscous than water. The particle concentration was 2.50 mg/mL for BaFe12O19 particle clusters and 1.00 mg/mL for Fe3O4 particle clusters. The magnetic particle cluster cross-sectional area ranged from 15 to 1000 μμm2, and the particle cluster diameter ranged from 5 to 45 μμm. The magnetic particle clusters were exposed to oscillating or rotating magnetic fields and imaged with an optical microscope. The oscillation frequency of the applied magnetic fields, which was created by homemade wire spools inserted into an optical microscope, ranged from 10 to 180 Hz. The magnetic field magnitudes varied from 0.25 to 9 mT. The minimum magnetic field required for particle cluster rotation or oscillation in glycerol was experimentally measured at different frequencies. The results are in qualitative agreement with a simplified model for single-domain magnetic particles, with an average deviation from the model of 1.7 ± 1.3. The observed difference may be accounted for by the fact that our simplified model does not include effects on particle cluster motion caused by randomly oriented domains in multi-domain magnetic particle clusters, irregular particle cluster size, or magnetic anisotropy, among other effects.

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