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Unlike polymers, glass is prone to fracturing under localized stress during roll embossing. Molds traditionally used for glass embossing are rigid and unsuitable for roll embossing. In this investigation, we utilized a modified soft polydimethylsiloxane (PDMS) mold, known for its ease of fabrication and superior replication capacity, for roller embossing on glass. This innovation significantly cuts mold expenses while preserving PDMS's hydrophobic and low surface energy attributes. Consequently, it prevents adhesion between the glass and the mold during high-temperature embossing, ensuring that the demolding process does not harm the glass surface. We successfully carried out roll embossing on optical glass with a mere 1.65 mm thickness, using a self-devised stainless steel carrier plate and a mobile induction heating apparatus. This heating methodology departs from the conventional practice of employing multiple heat sources in glass embossing and instead uses a singular heat source. Induction heating is applied directly to the mold and 420 stainless steel carrier. The optical glass surface reaches a remarkably uniform temperature, with a minimal temperature differential of only 2.5 °C, which is highly advantageous for mobile roller embossing, resulting in a high replication rate of V-groove microstructures on glass. [ABSTRACT FROM AUTHOR]

Water and other volatiles are present in the permanently shadowed region of the moon. Quantitative analysis of the content is of great significance for lunar resource assessment and geological evolution. However, no detector has yet carried out in situ analysis on the moon, and quantitative sampling and low-power thermal extraction of lunar regolith are also difficult. Thus, a systematic method is proposed to realize quantitative sampling & low power thermal extraction of lunar regolith that detects the abundances of volatiles more accurately. Considering the requirements of the amount and particle size of the regolith, a sampler with a specific structure and motions is designed to quantitatively collect some lunar regolith. After that, induction heating is applied to heat the sampler and indirectly increase the temperature of the internal lunar regolith for volatile thermal extraction. The results demonstrate that this sampling method can achieve high-quality quantitative sampling. Moreover, the sampler and sampled regolith can be heated to the desired temperature with low power consumption. This work offers a feasible solution for the lunar volatile exploration of Chang'E-7. • A method to quantitative sampling and heating lunar regolith is proposed. • Sampling method can realize a quantitative collection of lunar regolith. • Sampled lunar regolith can be heated to 900℃ with low power. [ABSTRACT FROM AUTHOR]

The paper presents a universal computational model of heating curves for walking beam furnaces, which allows to determine the temperature distribution along the length of the furnace during heating of the steel charge. The model was made based on analytical dependencies regarding transient heat conduction, taking into account the temperature variability of all thermo-physical properties. The methodology of calculations and examples of heating curves for selected cases are presented. [ABSTRACT FROM AUTHOR]

The development of new low‐carbon emission methods for the synthesis and processing of materials is an urgent task today. Here, we present a rapid, efficient, and low‐energy‐consuming synthesis method for high‐yield Ti3AlC2 MAX phase powders. Our method is based on induction heating‐assisted combustion synthesis (IH‐CS), where the heat of the reaction is used as a driving force of the process, and the conditions of the process are finely controlled using IH at the same time. Ti3AlC2 MAX phase was synthesized using TiC0.67 and Al powders as starting materials. The introduction of TiC0.67 reduced the total exothermic effect of the reaction, facilitating better control of the reaction process. IH was used to ignite the reaction and to hold the temperature after ignition at an optimal value to complete the synthesis process. The effects of holding temperature, Al, and Si addition on Ti3AlC2 yield were investigated. As a result, Ti3AlC2 MAX phase powders containing only.7 wt% of the secondary phase were synthesized in a very short time. Our findings suggest that IH‐CS is a highly effective and promising alternative for the facile fabrication of high‐purity MAX phase powders. [ABSTRACT FROM AUTHOR]

Hydrogen storage in metals is anticipated to be a highly promising technical approach for managing hydrogen in diverse energy applications, emphasizing the need to establish efficient operating conditions. In this study, we developed a numerical model that can simultaneously calculate hydrogen and heat transport combined with electromagnetic induction heating of metal particles. Using the developed numerical simulator, we investigated the behavior of the hydrogen release process from the hydrogen-absorbing metal and proposed important indicators for the operation. The fractions of the electromagnetic energy absorbed by the metal particle used for the hydrogen release, sensible heat, interfacial heat conduction, and thermal radiation were systematically evaluated. Considering the trade-off between temperature rise and the hydrogen concentration gradient, an optimal diameter of metal particles existed for the maximum hydrogen release rate. Similarly, the trade-off between temperature rise and energy consumption revealed an optimal electromagnetic power density for the heat utilization fraction for hydrogen release. Our electromagnetic–thermal–mass transport triple hybrid model constitutes a useful numerical simulator for the design of energy-efficient hydrogen storage systems. [Display omitted] • A novel numerical model for hydrogen transport is introduced. • Electromagnetic energy, thermal, and mass transport phenomena are combined. • Energy is tracked for hydrogen release, sensible heat, conduction, and radiation. • Optimal Ti particle diameter and electromagnetic power density are determined. • The model may aid in designing energy-efficient hydrogen storage systems. [ABSTRACT FROM AUTHOR]

In this work, a 3D analytical magnetic model based on hybridation of the sub-domain’s method and the image’s theory to compute magnetic field and translational motion eddy current in the conducting plate of the Halbach permanent magnet induction heater planar topology is developed. The main objective is to remedy the problem of the transverse edge effect, and hence improving the efficiency of analytical model and the accuracy of results. The developed model also allows fast and precise simulations of 3D magnetic phenomena, and presents an important reduction in computation time compared to 3D finite element simulations. [ABSTRACT FROM AUTHOR]

Addressing the issue of low bonding strength in Ti/Mg laminated composites due to interfacial oxidation, this study employs a differential temperature rolling method using longitudinal induction heating to fabricate Ti/Mg composite plates. The entire process is conducted under an argon gas protective atmosphere, which prevents interfacial oxidation while achieving uniform deformation. The effects of reduction on the mechanical properties and microstructure of the composite plates are thoroughly investigated. Results indicate that as the reduction increases, the bonding strength gradually increases, mainly attributed to the increased mechanical interlocking area and a broader element diffusion layer. This corresponds to a transition from a brittle to a ductile fracture at the microscopic tensile–shear fracture surface. When the reduction reaches 47.5%, the Ti/Mg interfacial strength reaches 63 MPa, which is approximately a 20% improvement compared to the bonded strength with previous oxidation at the interface. Notably, at a low reduction of 17.5%, the bonding strength is significantly enhanced by about one time. Additionally, it was found that a strong bonded interface at a high reduction is beneficial in hindering the propagation of interfacial cracks during tensile testing, enhancing the ability of the Ti/Mg composite plates to resist interfacial delamination. [ABSTRACT FROM AUTHOR]

This paper describes the procedure of electromagnetic and thermal modeling of an induction hardening load of 42CrMo4 steel. In addition to the temperature and field level dependent physical properties of the material, the magnetic behavior of the load is captured by means of some kind of non-linear impedance boundary condition which simplifies the computational cost of the simulation. The numerical results show the critical behavior around Curie temperature. Finally, a comparison between several simulation results and experimental measurements are provided to assess the usefulness of the proposed electro-thermal simulation. [ABSTRACT FROM AUTHOR]

Induction tube welding systems utilize an internal magnetic flux controller (impeder) to improve process efficiency. Work has previously been done showing that soft magnetic composite (SMC) materials may be suitable to improve these systems. A test stand was devised for the physical simulation of SMC impeder performance for use in induction tube welding systems. Tests were run to determine the loading and cooling conditions in which an impeder core made of SMCs could survive. Additionally, 2D thermal simulations were run to determine the cooling system thresholds given a particular magnetic loading of the core. The goal of these tests was to expand the design envelopes in which impeder cores made of SMCs could survive and validate their use in induction tube welding systems. [ABSTRACT FROM AUTHOR]

Energy efficiency is the primary objective in optimal design of inductive power components. This goal is totally aligned with the minimization of power losses in the coils. Typically, coils have been constructed by wire winding but, more recently, the utilization of printed circuit board (PCB) constructions has become more common due to their advantages, i. e. low profile and ease of fabrication, among others. At the operating frequencies of magnetic power devices, multi-conductor cabling with litz structure is required to reduce losses. PCB loss optimization procedure involves determining the number and size of the tracks. Numerical simulation is a very powerful tool to obtain the parameters of magnetic devices. However, including the internal structure of multi-track wiring in the numerical simulation implies a very high computational cost and a low accuracy of the results, because the size of the tracks is very small. Techniques of homogenization of the cabling are used to overcome such difficulty, disregarding the internal structure in order to determine the fields in the system and their electrical equivalent by means of computational simulation. The coil losses are further determined on the basis of the characteristics of the cabling as well as of the surrounding fields. The preceding procedure has proven to be suitable for cables composed of strands of circular cross-section, but should be adjusted to apply to tracks of rectangular cross-section. In this paper, different homogenization techniques for PCB coils have been proposed and evaluated. A highly symmetric reference system is selected to reduce the computational cost of numerical modeling, but the conclusions can be applied to more complicated geometries without loss of generality. Finally, the results of the different homogenization techniques have been validated by comparison with experimental results. [ABSTRACT FROM AUTHOR]

The analysis of the magnetic properties of alloys with low Curie temperature used in domestic induction heating is presented. These alloys allow the development of cookware with additional benefits with respect to regular cookware oriented to improve temperature control and the user's safety. Firstly, an experimental method to characterize the magnetic permeability with respect to the magnetic field strength and temperature in the material is presented. Secondly, a finite element simulation method is proposed which, considering the previous characterization, allows the calculation of the electrical equivalent of an inductor-load system as a function of temperature and magnetic field. This method makes possible the application of finite element simulation in the frequency domain with nonlinear materials, which is of interest for the design of electronics associated with domestic applications of induction heating. Simulation results are experimentally verified with various ferromagnetic alloys with low Curie temperature at different power, temperature, and operating frequency ranges. [ABSTRACT FROM AUTHOR]

Prosthetic implants, such as knee or hip prostheses, have significantly improved the wellbeing of citizens with articulation problems. However, there are still significant challenges in these procedures, being recurring infections one of the most challenging. In this context, hyperthermia has been studied as an effective alternative to antibiotics for biofilm eradication. Among the different heating alternatives, induction heating arises as the idoneous for this application due to its contactless nature and the metallic alloys used in prosthesis. This paper details the design of a portable induction heating system for implanted prosthesis disinfection. [ABSTRACT FROM AUTHOR]

Measure of temperature dynamics in induction sealing processes is of paramount importance for the validation of physics-based models. In this work, commonly used commercial tools for temperature measurements, such as thermocouples, pyrometers and thermal cameras, are benchmarked for the characterization of the temperature dynamics occurring in multilayer aluminum foil-based packaging material undergoing relatively fast (i.e., ×100 ms) induction heating transients. [ABSTRACT FROM AUTHOR]

Induction heating is an efficient and high-performance heating method which already has a significant market penetration and economic impact due to its benefits inherent to contactless energy transfer systems such as quickness, cleanness, and safety. Efficiency is a key design parameter since it determines not only the appliance performance but also its environmental impact, with significant socio-political implications. However, it is not easy to determine and compare the actual power converter efficiency operating under highly variable conditions typical of IH. This paper proposes an averaged efficiency parameter elaborated based on technical and typical IH usage conditions that offers a useful value to compare power converters operating under realistic operation conditions. The proposed parameter has been evaluated in some of the most significant power converter topologies used in reported state-of-the-art induction heating systems. [ABSTRACT FROM AUTHOR]

Promoting the Fe(II)/Fe(III) cycle efficiency is of wide interest for the broader applications of the Fenton process in water treatment sector. In this study, the alternating magnetic field (AMF) was employed to accelerate the reduction from Fe(III) to Fe(II). To achieve this purpose, a composite of nano-zero valence iron and NiFe2O4 was fabricated (denoted as Fe@NiFe2O4). Under the optimal reaction conditions, bisphenol A (BPA) was removed completely within 15 min by the Fe@NiFe2O4/H2O2 system in the presence of AMF, while only ∼60% was removed in the absence of AMF. The faster removal rate in the presence of AMF was ascribed to the elevated temperature caused by the inductive heating of Fe@NiFe2O4 (∼41°C according to the simulation). The simulator of the Fenton process was considered to be the leaked Fe(II) from the Fe part of the composite, as an equal concentration of Fe(II) (∼5.7 mg/L) resulted into a similar removal kinetic. However, the system with Fe@NiFe2O4 as the catalyst consumed less H2O2 in this process, indicating its different activation pathway from the conventional Fenton process. Electrochemical analysis confirmed that the AMF can generate the internal electric field within the composite particle. This field may facilitate the reduction from Fe(III) to Fe(II), which further benefitted the Fenton reactions. [ABSTRACT FROM AUTHOR]

This study demonstrates the use of photopolymerization to create semi-crystalline linear polymers suitable for thermally reversible materials in dental cast moldings produced from 3D printing. An aromatic diallyl, aliphatic dithiol chain extender, and monofunctional thiol were used in a photoinitiated system. The photopolymerization and crystallization kinetics as a function of chemistry and temperature were investigated using spectroscopy and calorimetry. These insights were used to realize vat photopolymerization-based 3D printing of functional objects that could be remotely melted and thereby removed using induction heating. The addition of monothiol was shown to decrease the polymer molecular weight which correspondingly increased the crystallization rate. Photopolymerization kinetics are independent of temperature while crystallization was slowed as the temperature approaches the melting point of the materials. Through inclusion of chromium oxide, semicrystalline materials could be melted through induction heating. These materials were implemented in vat photopolymerization 3D printing to realize high-resolution objects that could be used as releasable dental molds following printing and induction heating. This work demonstrates a proof-of-concept methodology to realize directly printable, thermally reversible semicrystalline materials for potential use as dental molding materials. [ABSTRACT FROM AUTHOR]

We investigated the debonding on-demand (DoD) of adhesively bonded hybrid dissimilar joints by applying electromagnetic induction heating to the joint overlap section, wherein the epoxy resin is reinforced with iron oxide (Fe3O4) particles. Ti-6Al-4 V adherends were bonded with CFRP or GFRP adherends using neat/modified epoxy adhesive. DoD tests revealed that eddy current heating of Ti-6Al-4 V was a dominant heating mechanism of the joints while both eddy current and magnetic hysteresis of CFRP and Fe3O4 acted as a secondary heating factor. A low content Fe3O4 and thinner composite adherend reduced the time to failure of the joints. Likewise, CFRP required a shorter time for debonding compared to GFRP due to its electromagnetic properties. Modifications with 2 and 5 wt.% Fe3O4 for CFRP and GFRP joints led to 31% and 37% time reduction which will be crucial for energy-saving when debonding large structures. Remarkably, sandblasting improved the electromagnetic induction capabilities of Ti-6Al-4 V, leading to a notable increase in the heating rate, which jumped from around 20°C/s to 80°C/s. Sandblasting enhanced the surface roughness of the adherends but only the water contact angle of GFRP decreased considerably. Fe3O4 modifications increased the epoxy residue on the Ti-6Al-4 V surface from 26% to 99%. DIC revealed the strain distribution of bulk materials to understand the thermomechanical mismatches between the materials and the adhesive joints exhibited high peel stresses at the overlap ends. The low weight content (2 and 5 wt.%) of Fe3O4 exhibited beneficial effects on the mechanical, thermal, thermomechanical, wettability and lap shear strength. [ABSTRACT FROM AUTHOR]

This paper presents new resonant inverter topologies for dual-frequency induction heating (IH). These 2T1C and 3T topologies combine the advantageous features of two- and one-inverter solutions. An analytical description of the load impedance of a dual-frequency series-parallel circuit has been made. Using manufacturer datasheets and LTspice models of selected transistors, a MATLAB model was parameterized. Based on it, power losses are determined as a function of the following parameters: nominal power, frequency and DC bus voltage. The obtained results allowed for determining the data necessary in the design process. The research has been experimentally verified. Tests were carried out for pulsing and simultaneous operation. Power control characteristics as a function of frequency are determined. The possibility of operating the inverter with high efficiency (>97%) in the proposed 2T1C and 3T systems at nominal power is demonstrated. [ABSTRACT FROM AUTHOR]

Addressing the issues of low heating efficiency and high carbon emissions in traditional biomass pyrolysis processes, this study explores the potential of induction heating fluidized bed pyrolysis reactor (IHFBR) to enhance heating efficiency, reduce carbon emissions, and increase syngas yield during biomass pyrolysis. The effects of induction heating power (5.7–6.8 kW), carrier gas flowrate (200–800 ml/min), reaction time (2–8 min), and fluidizing medium mass (0–33.0 g) on the yield of gas, liquid, solid products from tobacco stem (TS) pyrolysis in the IHFBR are assessed. The results show IHFBR demonstrates higher syngas yield from TS pyrolysis, reaching 356.9 ml/g-TS at 700 °C and 6 min, with CO and H 2 comprising 28.5 vol% and 29.6 vol% of the total gas volume, respectively. This represents a substantial increase in syngas yield by 67.6%, 137.2%, and 526.9%, respectively, compared to conventional fluidized bed, induction and resistance furnace heating fixed beds. [Display omitted] • Induction heating fluidized bed reactor (IHFBR) is developed for biomass pyrolysis. • Tungsten rod with fast self-heating rate (9.7–20.3 °C/s) serves as induction medium. • IHFBR creates localized high-temperature zones and enhances mass/heat transfer. • IHFBR achieves lower solid and liquid yields, and higher gas and syngas yields. • IHFBR boosts syngas by 67.6%, 137.2%, and 526.9% compared to traditional methods. [ABSTRACT FROM AUTHOR]

In recent years, SiC single crystal growth technology has been developed toward larger size and thickness to reduce the cost of SiC-based power devices. Resistance heating has gradually become a hot spot for research because the crystals grown by the induction heating display the disadvantages of high stress and defect density. In this paper, the design of resistance heaters for SiC crystal growth was thoroughly investigated via numerical simulation. A simulation of the thermal field generated by different resistive heater arrangements was performed. The stress and dislocation distribution in crystals under different growth conditions were studied. Based on the comprehensive requirements of a small radial temperature gradient and a large growth rate, the arrangement and length of the resistance heater were proposed. This study would serve as a useful guidance for the study of SiC growth by resistive heating. [ABSTRACT FROM AUTHOR]

The inductive heating of a CMC susceptor for industrial applications can generate very high process temperatures. Thus, the behavior of a silicon carbide-based matrix with carbon-fiber-reinforced carbon (C/C-SiC) as a susceptor is investigated. Specifically, the influence of fiber length and the distribution of carbon fibers in the composite were investigated to find out the best parameters for the most efficient heating. For a multi-factorial set of requirements with a combination of filling levels and fiber lengths, a theoretical correlation of the material structure can be used as part of a digital model. Multi-physical simulation was performed to study the behavior of an alternating magnetic field generated by an inducing coil. The simulation results were verified by practical tests. It is shown that the inductive heating of a C/C-SiC susceptor can reach very high temperatures in a particularly fast and efficient way without oxidizing if it is ensured that a silicon carbide-based matrix completely encloses the fibers. [ABSTRACT FROM AUTHOR]

Domestic induction heaters provide efficient, fast, and safe heating. Variable circuit parameters in domestic induction heaters show different characteristics depending on the type of parts used for heating and the area they cover on the heating coil. For this reason, resonant frequency, maximum inverter current, and quality factor parameters of the induction heaters also change. In this study, the tests of the domestic induction heater circuit with series resonant inverter were carried out with various of workpieces diameters. The resonant frequency and maximum inverter current parameters obtained from the experimental studies, curve fitting process was performed in the MATLAB and a function on related with heater parameters was derived. By using the obtained functions, the resonant frequency and maximum inverter current of the materials in the workpieces with intermediate diameters were calculated with high accuracy and compared experimentally. Analytical calculations and experimental results confirmed each other with an accuracy and it was shown that induction heater circuit parameters could also be calculated by analytical solution method. [ABSTRACT FROM AUTHOR]

Induction healing technology can effectively repair microcracks in asphalt mixtures and is a promising maintenance technology for asphalt pavements. However, it requires the addition of steel wool fibers to asphalt mixtures and cannot be directly used to repair existing pavements. In order to improve the practicality of the induction healing technology, this article designs a wearing course asphalt mixture with induction healing function that is going to be paved above the existing road surface. The AC-10 asphalt wearing course for induction heating was prepared by adding steel fiber (SF). Analysis of the overall temperature of the surface revealed the unevenness of the temperature distribution, and the healing properties were investigated through protective heating that controlled the maximum temperature of the upper surface. The results show that the addition of SF can improve the high-temperature stability, low-temperature and intermediate-temperature crack resistance, and moisture stability of asphalt wearing courses; however, it has adverse effects on volumetric performance and skid resistance. The heating temperature increases with the increase in SF content, but higher maximum temperature heating rate causes worse heating uniformity and lower healing effect. The maximum heating rate of the sample with 10% SF reaches 3.92 °C/s, while its heating rate at minimum temperature is similar to that of the sample with 6% SF, which is only 0.7 °C/s, indicating the worst heating uniformity. The best healing effect occurs when the maximum temperature of the upper surface reaches 160 °C. The recommended optimal SF content is 6% of the asphalt volume. The asphalt mixture with 6% SF has an appropriate volume performance, moisture stability, and skid resistance; additionally, it has the best high-temperature stability, as well as low-temperature and intermediate-temperature crack resistance. Meanwhile, it also has uniform temperature distribution and efficient healing efficiency. [ABSTRACT FROM AUTHOR]

The use of adhesive bonding in the milling tool industry has been reported as advantageous, when compared with the industry's standard, i.e. brazed joints. This work focuses on improving a previously developed jigless manufacturing process – i.e. induction pre-curing – used to produce woodworking tools. To reduce production times, two tactics were employed to accelerate the induction process. Different coil geometries, changing the magnetic field intensity, and a ferromagnetic filler, promoting internal heat generation. It was found that these methods do not improve the heating process in a significant way. Therefore, the standard alternative, i.e. full oven curing, was also tested. Using small-scale real joint specimens, the shear resistance of both curing procedures was compared. This revealed that oven curing provides two times more strength. As such, a new joint geometry was developed, to facilitate the process of oven curing full milling tools, now fabricated with fixing jigs. In conclusion, the induction heating process was deemed unfeasible, and, as such, oven curing became the recommended method. Several milling tool prototypes were manufactured and validated both in laboratory and real-world conditions, through costumer focused testing. These tests showed good tool performance and workpiece surface quality. [ABSTRACT FROM AUTHOR]

In this study, the electrical conductivity of PolyEtherKetoneKetone reinforced with five harness satin weave carbon fabric was measured. Induction heating experiments using a hairpin shaped coil were conducted on the same material. The study points out that the thermal response depends on the direction in which the eddy currents are generated in the laminate. The thermal response showed a linear relation with the measured in-plane anisotropic electrical conductivity, pointing towards Ohmic heating mechanisms being dominant during induction heating of the used material. This relation enables the accurate and efficient simulation of the induction heating of woven fabric reinforced composites, using only the electrical conductivity measured in one of the fabric's weave directions and in the fabric's 45° off-axis direction. [ABSTRACT FROM AUTHOR]

Carbon foams with and without functional particles were prepared via a simple direct foaming process. The carbon foams were composed of pyrolytic carbon and graphite. In the foams with additional functional particles, the latter were integrated directly in the direct foaming process. These functional particles were the catalytic material Saponite and the induction heat‐able material MagSilica®. The foams were characterized including the induction heatability. The foams were also successfully tested in an induction heated lab‐scale reactor for a case study reaction, ethanol to 1,3‐butadiene. [ABSTRACT FROM AUTHOR]

With the development of light-emitting diodes (LEDs) display and lighting industry, new requirements have been put forward for phosphors. Traditional syntheses of phosphors face the problems of slow temperature increase, long holding time and corresponding larger particle size. In this work, a co-precipitation combined with induction heating method was developed for the fast and efficient synthesis of Lu 2.97 Al 5 O 12 :0.03Ce3+ (LuAG:0.03Ce) phosphors. The effects of calcination temperature and holding time on the morphology and luminescence properties were investigated. The phosphor synthesized at 1600 °C for 10 min (10 min@1600 °C) has an average particle size of 500 nm, and exhibits good luminescence properties and thermal stability (maintaining 92.04 % of room temperature light intensity at 200 °C). The luminescence intensity and the external quantum efficiency (EQE) of the phosphor (60 min@1500 °C) are higher than those of a commercial phosphor. The light source fabricated with phosphor ceramic prepared by the phosphor (10 min@1500 °C) shows a luminous efficacy (LE) of 193 lm/W. Therefore, co-precipitation combined with induction heating is an energy-saving and promising method for the synthesis of phosphor. [ABSTRACT FROM AUTHOR]

Out-of-oven curing of epoxy resins with economical and energy-efficient techniques is vital for manufacturing advanced composite structures. In this study, the effects of a magnetic particle (MP)-induced in situ heating technique on the heating temperatures and mechanical properties of epoxy resins were investigated. The results showed that the proposed technique quickly increased the epoxy resin temperature and steadily heated the polymer until it was fully cured. With increasing MP concentrations from 6 wt% to 22 wt%, a notable increase in the heating ratio from 3.27 °C/min to 8.96 °C/min and steady increases in the heating temperature from 92.61 °C to 115.03 °C were observed. Surface modification of the MPs improved the homogeneity of the heating field and cross-linking and also increased the heating ratio and steady heating temperature. With merely 2.5 h of induction heating, the flexural moduli and strengths of functionalized MP/epoxy samples with MP loads of 6 wt%, 13 wt% and 22 wt% were 45.1%, 42.8%, 40.5% and 6.3%, 33.5%, 39.4% higher than those of oven-cured control samples. These findings provide essential knowledge for fabricating advanced polymeric composite structures without an oven. [ABSTRACT FROM AUTHOR]

Understanding the recrystallization behavior of cold‐rolled silicon steel during continuous heating is essential for optimizing continuous annealing parameters and accurately controlling material performance. To address the limitations of isothermal annealing studies in interpreting actual continuous annealing processes, this study investigates the recrystallization kinetics of Fe–2.3 wt%Si steel using a continuous heating three‐point bending method. The method effectively determines the characteristic recrystallization temperatures. Interestingly, these recrystallization characteristic temperatures remain unaffected by the initial load but shift toward higher temperatures with increasing heating rates in the range of 5–15 °C min−1. The average activation energy of recrystallization is estimated to be 144.5 kJ mol−1, comparable to the value of 147.0 kJ mol−1 obtained from the isothermal process through microhardness measurement. The recrystallization kinetics, described by an extended version of the Ozawa–Flynn–Wall model, exhibits excellent agreement with experimental evaluations. By combining the present processing technologies with continuous heating recrystallization kinetics, different recrystallization temperatures and times can be determined, offering valuable insights for optimizing annealing processes. [ABSTRACT FROM AUTHOR]

The impact of induction heating on the self-healing of asphalt mixture test specimens prepared with scrap metal and styrene–butadiene–styrene (SBS) modified bitumen was investigated in this study. In addition, the effects of waste metals used instead of aggregates in asphalt mixtures on the asphalt mixtures' mechanical properties were determined. To this end, asphalt mixtures were prepared to use two different percentages (inst aggregates of 50% and 100% aggregates) of waste metal in two different mill scale (cold mill scale and hot mill scale) and SBS in two different percentages (2% and 3%) to create prismatic and Marshall asphalt test specimens. Induction heating systems were used to determine self-healing properties. The samples were heated in five different heating times as 120 s, 100 s, 80 s, 60 s, and 40 s. To measure the performance of the recovery processing, five recovery cycles were performed for every asphalt sample. According to the results, the hardness of the mixtures, the mixes' fatigue life and load repetitions both shorten as the waste metal usage ratio in the asphalt mixtures increases. As both the amount of sludge and the amount of SBS in the asphalt mixtures increase, the maximum temperatures of the asphalt mixtures also increase. When the SBS ratio in the asphalt mixtures increases, the recovery rates increase. In addition, as the waste metal content in the asphalt mixture increases, an increase in HL values is observed. Finally, the general binding and rheological properties of SBS modified binders were evaluated. [ABSTRACT FROM AUTHOR]

Hot metal gas forming (HMGF) of tubular profiles enables intricate designs for lightweight material production. HMGF showed an immense manufacturing potential, due to the excellent strength and toughness of the formed parts, better material formability, and better dimensional accuracy of the final product. Existing part production methods, such as weld-assembly of stampings and hydroforming, have significant problems in terms of residual tensile stresses, which can affect the formability and negatively affect the performance capability of the structural components. Due to the lack of a detailed review report, the primary focus of this review article is to provide in-depth analysis of recent developments, innovations, and challenges in HMGF while comparing it to existing manufacturing methods. This examination includes different essential aspects, such as the process principle, material applications, deformation mechanisms, process parameter optimization, and microstructure modeling. Additionally, the article explores future research directions and the potential of HMGF in the manufacturing industry. Our review underscores the critical importance of optimizing process parameters and conducting microstructural analysis to meet evolving challenges. Further research on material models and the interplay of microstructural variables is essential for advancing the field and facilitating precise predictions in HMGF processes. [ABSTRACT FROM AUTHOR]

Dewatering of alkali metal halide salts in conventional co-current or counter-current spray driers to obtain low moisture content and agglomeration in resultant dried powders is difficult owing to their hygroscopic nature. Co-current spray driers offer the advantage of good heat transport characteristics in spray zone while counter-current spray driers offer better thermal utilization throughout the drying chamber. In the present work, modified prototype of a conventional counter-current spray drier is developed to obtain both these advantages in the drying chamber by employing induction heating and mechanical pulsation techniques. After carrying out several experiments in this prototype viz. Induction heating-based pulsed spray drier (IH-PSD), the optimal process parameters are obtained which maximize thermal utilization throughout the drying chamber and minimize both moisture content and agglomeration in resultant dried powders of sodium and potassium halide salts. The initial droplet and final particle size distributions are obtained using laser diffraction analyzer and sieve shaker experiments respectively. An experimentally validated numerical model implemented using open-source computational solvers is utilized to obtain average drying rates in IH-PSD. It is observed that the average drying rate lies between 0.03 and 0.18 mg/s and 0.04 and 0.14 mg/s for sodium and potassium metal halide salts respectively. Spray drying prototype coupled with Induction heating and mechanical pulsation. Dewatering of sodium and potassium metal halide salts using the spray drying prototype. Numerical-neural network model implemented by open source computational solvers. Utilization of Laser diffraction analyser for measurement of initial droplet size. Model calculates the average drying rate with an accuracy around 83%. [ABSTRACT FROM AUTHOR]

We explore the relationship between rough surface conductors and the phenomenon of passive intermodulation. The underlying surface is taken to be the boundary of a Lipschitz domain, and a characteristic angle of the domain is used to track boundary dependence on the various fields. To model electro‐thermal passive intermodulation in particular, we consider a specific type of temperature‐dependent conductivity and determine conditions on the conductivity under which one can use fixed point arguments to solve an induction heating and Joule heating problem on a Lipschitz domain. In the latter problem, we also consider a time‐dependent permittivity function ε$\varepsilon$. Finally, weak solutions to a magneto‐quasi‐static problem are obtained when the permeability µ is temperature dependent and is allowed to degenerate in a certain way. An interesting effect of the rough surface is the inherently limited Sobolev regularity of the electric field, which can be improved if one assumes additional constraints on the boundary. [ABSTRACT FROM AUTHOR]

Summary This article proposes a method to transfer maximum power from a power supply to an induction heating load by matching the dynamic resistance of the induction heating resonant circuit with the internal resistance of the power supply source. The method is to select a capacitor connected in parallel to the induction coil and tune the correct value of the inverter frequency to the induction heating circuit resonant frequency. The proposed method can be used for heating work loads with an energy‐saving purpose in induction heating applications. The switching frequency of the single‐phase full‐bridge inverter is variable so that the inverter frequency can be matched with the coil and parallel‐connected capacitor (RLC tank circuit) resonant frequencies. To demonstrate the feasibility of the load‐matching technique proposed, we experimented with two types of loads that were both stainless steel vessel containers with almost similar size and dimensions but different magnetic properties. We conducted experiments based on the proposed technique and obtained satisfactory results that supported our synopsis. The methods used to collect and analyze the data were carefully chosen and have been described in the methodology section of the research paper. [ABSTRACT FROM AUTHOR]

Extreme-high-speed laser cladding (EHLA), as a novel surface treatment technique, has attracted great attention because of its high cladding rate and good performance of cladding coatings. However, when depositing coatings with high cracking susceptibility, such as Ni60 coatings, cracks are difficult to avoid. Therefore, an extreme-high-speed laser-induction hybrid cladding technology (EH-LIHC) was innovatively proposed in this study. The effects of different preheating temperatures on the surface morphology, internal defects, microstructure, and mechanical properties of Ni60 coatings that were deposited by EHLA and EH-LIHC were analyzed. The results show that the roughness of the coating deposited by EHLA is 26.228 μm. However, the surface roughness of the coating deposited by EH-LIHC at 400 ℃ decreases to 14.316 μm. Simultaneously, the pores- and cracks-free Ni60 coating was deposited at 400 ℃. The coating dilution rate obviously increases as the preheating temperature rises. When the preheating temperature rises, the size of the grains and precipitates also increases. However, although Fe elemental diffusion is increased, there is no significant effect on the properties of the coating. The hardness of the coating fluctuates between 700 and 900 HV, nearly three times that of the substrate. As the preheating temperature rises, the coating's wear mechanism shifts from abrasive to abrasive and adhesive wear, and eventually back to abrasive wear. The improvement of wear resistance of the Ni60 coating deposited at 400 ℃ was mainly attributed to its high hardness and uniform and dense microstructure. The proposed EH-LIHC technique provides a promising method for the efficient deposit of crack-free coatings with good properties. [ABSTRACT FROM AUTHOR]

Summary: Single‐phase high‐frequency resonant inverters (SPHFRIs) with high power density, fast dynamic response, and high energy conversion efficiency have been widely studied and used in academia and industry. With the development of the modularization concept, the operation of multiple inverter modules is desirable because it can remove the limitations of cost, heat dissipation, and component volume in single inverter operation. However, a critical challenge in multiple inverter systems is that the both the phase and magnitude of the output voltage of each inverter module must be controllable to eliminate circulating currents between inverter modules. Great efforts have been made to solve this problem from three aspects: topology, modulation, and control strategy. In this paper, modulation strategies and topologies of different inverters are presented and reviewed to provide guidance to researchers working in this field. Firstly, multiple inverter system based on the SPHFRI is described and its advantages and disadvantages are analyzed. An important issue in the study of multiple inverter systems is presented, that is, the suppression of circulating current. Secondly, the circulating currents in a multiple inverter system are analyzed and derived from two aspects: (1) magnitude and phase angle and (2) active and reactive currents. Thirdly, the inverters used in the multiple inverter system are introduced, and their operating principles, advantages, and disadvantages are reviewed. A key comparison of several inverters is presented for the benefit of the readers. Fourth, through PI closed‐loop simulation, the performance of different multiple inverter systems for suppressing the circulating current is compared in two situations: (1) with magnitude discrepancy only and (2) with both magnitude and phase discrepancy. Finally, the advantages and disadvantages of each inverter are summarized, and the state of the art and future trends are presented. [ABSTRACT FROM AUTHOR]

Steel fiber (SF) has been widely used in asphalt mixtures to provide efficient induction heating and improve performance. However, the application of SF in asphalt mixtures still faces the issues of mixing difficulty, further performance improvement, and increased cost. To try to alleviate these issues, brucite fiber (BF) and fiber granulation technology have been adopted. First, SF and BF were mixed into the mixture according to different volume ratios. Based on the research results of engineering performance, the optimal total content and optimal volume ratio of SF and BF were determined. respectively. Then, SF and BF were prepared into a composite granular fiber (CGF). Finally, the performance of the mixture including CGF was verified, its economy was evaluated, and its mechanism was analyzed. The results show that the optimal total content of SF and BF is 0.6% and the optimal volume ratio of SF to BF is 3:2. The high-temperature rutting resistance, low-temperature cracking resistance, and moisture sensitivity of CGF are superior to that of the control sample and SF asphalt mixture, with percentages of 15.1%, 4.2%; 49.4%, 23.4%; 14.5%, 6.7% respectively. A mechanistic analysis described why CGF performed better than SF. The cost performance of the asphalt mixture with CGF surpasses that of SF, with CGF being 32.2% higher. [ABSTRACT FROM AUTHOR]

Patching is a common pavement treatment, and it is implemented using hot and cold process patching. Hot process patching is not an efficient implementation method because keeping asphalt temperature in long hauls is difficult, on-site mixing equipment is required, and transport costs are generally high. Moreover, hot process patching requires a significant amount of energy, so it is not an eco-friendly process. Although cold process patching significantly reduces the energy consumption of patching, its implementation reduces the patching quality. To this end, this study aimed to propose a new cold process patching using induction heating. Furthermore, this study attempted to apply waste materials in the proposed mixtures to preserve the environment. Accordingly, high percentages of reclaimed asphalt pavement (RAP) were used in the proposed mixture. Since induction heating was applied in the introduced patching method, two waste materials, including steel slag and electronic waste, were utilized in the mixtures to enhance the sensitivity to electromagnetic radiation. Moreover, different experimental tests were conducted to evaluate the mixtures' mechanical properties. Ultimately, gray relational analysis was performed to assess the proposed mixtures' sustainability. The results indicated that using steel slag and electronic waste as conductive materials could considerably reduce the heating time to raise the fabricated mixtures' temperature. Moreover, replacing the Neat mixture with the proposed asphalt mixtures containing the waste materials significantly reduced the unit price, greenhouse gas emission, energy consumption, and raw material utilization. [ABSTRACT FROM AUTHOR]

The mechanisms of intragrain plastic deformation occurring in local micro-volumes of metal under the influence of temperature stresses during high-speed heating due to high-energy exposure are studied. The temperature distribution over the thickness of the sample is calculated and its experimental verification is carried out. Samples of steel 12Cr18Ni10, which does not undergo phase transformations during heating and cooling, are examined after a treatment with scanning air-plasma arc. It is shown that the intragrain plastic deformation during heating of austenitic steel is caused by thermoelastic stresses arising in the heated layer and in the volumes bordering it and manifests itself in the appearance of sliding traces in the grains. The mechanisms of the appearance of temperature stresses in the metal are proposed and substantiated. [ABSTRACT FROM AUTHOR]

The objective of this study is to examine how different parameters impact the effectiveness of alkaline water electrolysis (AWE) in producing hydrogen. Multiple experimental innovative approaches have been examined, namely, mechanically induced electrolyte flow, induction heating of electrodes, and pulsating voltage power mode. In addition, multiple parameters that have been experimentally investigated, including concentration of potassium hydroxide (KOH) solution, input current density, electrode spacing, electrode thickness, cell temperature, electrode coating material, and electrode morphology. The results obtained from these tests show significant improvements in AWE performance and efficiency. A better understanding of the behavior of AWE and the factors that influence its performance has been presented through a detailed discussion of the experimental results. The results have shown that reducing the gap size between electrodes improves AWE efficiency, however this relation is not monotonic and after a critical gap size the performance starts deteriorating. Furthermore, the localized induction heating has shown an improvement in the overall efficiency by approximately 8 % accompanied by a marginal increase in the global system temperature of around 4.2 °C. • The study examines the effect of different operating conditions on alkaline water electrolysis performance. • The study examines the effect of electrode parameter such as spacing and surface roughness on alkaline water electrolysis performance. • Investigate novel techniques to improves alkaline water electrolysis using induced electrolyte flow, induction heating and pulsating voltage. [ABSTRACT FROM AUTHOR]

Reliable information about the properties of the processed materials has a significant impact on the effects of their processing. In induction heating processes, this also applies to information about the influence of temperature T on these properties. These are both thermal and electro-magnetic properties. Based on previous studies, a comprehensive experimental method is presented for estimating the temperature characteristics of thermal diffusivity, volumetric heat capacity and resistivity on one measurement station, with particular attention to ferromagnetic materials. The estimation process is carried out on an induction heating stand using forcing signals from an inverter generator. In a computer-controlled cycle that changes the base temperature level, basic measurements of thermal and electrical properties are carried out on a material sample in the form of a cylindrical disk. They are the results of the analysis of the temperature and electromagnetic responses of a material sample to short- and long-term step pulses of a sinusoidal excitation signal with a frequency of approximately 40 kHz. The presented estimation method can be treated as a final method or a preliminary procedure for radically narrowing the variability in decision variables inthe optimization process of simultaneous determination of the sought material characteristics. [ABSTRACT FROM AUTHOR]

The standards within the global steel industry are constantly advancing, necessitating increasingly rigorous quality control protocols during the continuous casting process. Central to the challenges faced in this domain are persistent defects such as central segregation, V-shaped segregation, and center porosity, which significantly impede the production of high-caliber steel products. The discipline of electromagnetic metallurgy has emerged as a critical solution in reducing these defects, thereby enhancing the efficiency and stability of continuous casting operations. Its demonstrated effectiveness has led to its widespread implementation across global and domestic steel production industries. This paper aims to deliver a comprehensive examination of electromagnetic metallurgy's impact on the final stages of solidification in continuous casting, along with its contributions to the heating and purification processes within the tundish. Additionally, it will explore the potential advancements and applications of this technology in the evolving sphere of continuous casting. [ABSTRACT FROM AUTHOR]

High-temperature superconducting (HTS) DC induction heating technology has the advantage of high heating efficiency, no harmonic pollution, uniform heating, etc., which is much better than the traditional AC induction heating technology in industrial heating applications. A dipole-type HTS DC induction heater is proposed in this paper, and the operating characteristics of the HTS magnet are analyzed. The HTS magnet consists of a dipole iron core, two racetrack coils wound with YBCO tapes, and a liquid nitrogen cryostat. Two racetrack coils are installed in the two iron yokes, and the magnetic field is generated in the air gap between the two iron yokes. When induction heating, the object to be heated is placed in this air gap and rotated, which in turn generates eddy currents and then heats. The HTS magnet is cooled by liquid nitrogen, and a DC magnetic field is generated by the HTS magnet in the air gap in the iron core. The critical current of the used YBCO tape is larger than 140 A at 77 K, self-field, and the tested critical current of the coil is 70 A. The testing results show that the axial magnetic flux density at the iron core air gap is 156 mT while the operating current of the coil is 60 A, which is consistent with the simulation results. [ABSTRACT FROM AUTHOR]

This article proposes a simple and fast method of induction heating and quenching to produce surface gradient structure for S38C steel, and its mechanical behavior and strengthening mechanism are revealed. The variation of the gradient structure from surface to interior is characterized by electron backscatter diffraction, and the tensile behavior of the gradient structure at different depths is acknowledged by the small‐scale tensile tests. The gradient structure is tempered martensite microstructure, which significantly improves the hardness and tensile strength of surface and subsurface regions. Accordingly, with the strengthening of the gradient structure, the general tensile strength and fatigue behavior of the S38C steel are increased close to those of high‐strength steel. Moreover, the fatigue crack initiation mechanism of the gradient structure is studied by energy dispersive spectroscopy, transmission Kikuchi diffraction, and transmission electron microscope characterization on the crack initiation regions. It reveals that the fatigue failure of the gradient structure can be due to stress concentration on the surface and around subsurface inclusions, and the crack initiation modes present surface crack initiation and internal crack initiation, respectively. [ABSTRACT FROM AUTHOR]

Integrated induction heating and mechanical rolling forming (IH-MRF) is a new method for producing complex curvature hull plates. The plate undergoes deformation through sequential or simultaneous action of induction heating and mechanical rolling. Understanding the mechanism of this forming process is essential for developing intelligent forming systems. Finite element simulation is a leading research tool in this area. However, the rigorous requirements on the number of model nodes and incremental steps of the simulation for direct modeling of inductor and rollers result in inefficient modeling and calculation processes. To address this issue, an equivalent load model for IH-MRF simulation is proposed in this study. The inductor is simplified to an equivalent heat source model, and the roller is simplified to an equivalent mechanical load model. The equivalent load model for the simultaneous action of induction heating and mechanical rolling is a simple superposition of the equivalent heat source model and the equivalent mechanical load model. The experiment and simulation results are consistent in terms of temperature trends, temperature values, and deformation. The research in this paper lays the foundation for developing an intelligent IH-MRF forming system based on finite element simulation methods. [ABSTRACT FROM AUTHOR]

Induction heating (IH) is the most preferred technology for domestic and industrial heating applications owing to its advantages over conventional heating methods. Heating requirements for ferromagnetic (FM) and non-ferromagnetic (N-FM) materials are different. There is an increase in research for heating these different material vessels. In this research work, a three switch dual frequency resonant inverter (3 S-DFRI) with dual frequency control is proposed. It has been used for simultaneous and independent heating of steel and aluminum loads. The inverter operation is verified by rigorous simulation and experimentation on the developed 2 kW prototype. It can also be extended for multiple loads by additional inverter legs each with three switches. Each additional leg provides two independent load operation. Compatibility with different material IH loads, reduced number of switching devices, no use of electro-mechanical switches, compact size and high efficiency are the key advantages of the proposed inverter. [ABSTRACT FROM AUTHOR]

Transition processes in a steel conductive strip are analyzed during its induction heating under a quasi-steady electromagnetic field. In particular, the temperature field in the strip is studied. A method of solving corresponding initial boundary problems in a two-dimensional mathematical model for differential equations of electrodynamics and heat conduction is developed. The Joule heat and the temperature are determined with a high level of accuracy. The defining functions are the temperature and component of the magnetic field intensity vector tangent to the bases and end planes of the strip. To find them, we use cubic approximation of the defining functions' distribution along the thickness coordinate. The original two-dimensional initial boundary value problems for the defining functions are reduced to one-dimensional initial boundary value problems on their integral characteristics. General solutions for these problems are obtained using the finite integral transformation by the transverse variable and the Laplace transform of the integral by time. Integral characteristics' expressions are represented as convolutions for functions that describe homogeneous solutions of one-dimensional initial boundary value problems and limiting values of defining functions on the bases and end planes of the strip. The change of temperature under a varying regime in the dimensionless Fourier time and temperature distribution over the strip cross-section in a steady state depending on the parameters of induction heating and the Biot number are numerically analyzed. Varying and constant temperature regimes of the strip under conditions of the near-surface and continuous induction heating are studied. [ABSTRACT FROM AUTHOR]

Nowadays, multilevel inverter (MLI)-based induction heating (IH) technology is the best-suited option in many domestic, commercial and medicinal applications because of its higher efficiency, low cost, fast heating and lower electromagnetic interference (EMI). This paper presents reduced components count high-frequency (HF) single phase five-level (5-L) MLI for IH applications. The working methodology of the proposed system has been analyzed in the multicarrier phase disposition pulse width modulation (MC-PD-PWM) method in high switching frequency i.e., 10 kHz. In addition, the proposed topology can produce output voltage twice of input voltage without any external source. Moreover, the detailed power loss and reliability analysis have been evaluated for the proposed system. In terms of switch count and efficiency, the single-phase 5-L inverter architecture is compared to some conventional and current topologies. Finally, to validate and justify the operation of the proposed system, the simulation and experimental results of five-level inverter are presented. [ABSTRACT FROM AUTHOR]

This study presents an induction heating-based reactor for on-board methanol steam reforming for hydrogen production reactors and distributed hydrogen refueling stations, with the goal of developing a hydrogen production process with zero carbon emissions. The numerical results showed that the enhanced hydrogen production performance and temperature cold spots could be eliminated, and the methanol conversion was close to 100%. at 150 A and 20 kHz. Induction heating may significantly shorten the reactor's cold start-up time. Under 50 kHz, the temperature of the reactor wall can reach more than 500 K in 50 s, in other words, induction heating overcomes the problems of slowly heating/cooling rate for on-board methanol steam reforming for hydrogen generation reactors. Overall, this study supports the feasibility of producing green hydrogen with zero carbon emissions for advancing the development of an environmental hydrogen economy and the cold start-up of distributed hydrogen energy and vehicle-used hydrogen production equipment. • Green methanol reforming via induction heating has the potential to produce zero carbon emissions. • The reactor allows for fast a cold start and a simpler structure. • Induction heating allows for precise temperature control and near-complete methanol conversion. • Coupled calculations for catalytic reforming reaction and induction heating. [ABSTRACT FROM AUTHOR]