Search Results (31)

This study investigates the influence of temperature measurement accuracy on tool failure mechanisms in industrial hot forging processes. Challenges related to extreme operational conditions, including high temperatures, limited access to measurement surfaces, and optical interferences, significantly hinder reliable data acquisition. Thermal imaging, pyrometry, thermocouples, and finite element modeling were employed to characterize temperature distributions in forging tools and billets. Analysis of multi-stage forging of stainless steel valve forgings revealed significant discrepancies between induction heater settings and actual billet surface temperatures, measured by thermal imaging. This thermal non-uniformity led to localized underheating and insufficient dissolution of hard inclusions, confirmed by dilatometric tests, resulting in billet jamming and premature tool failure. In slender bolt-type forgings, excessive or improperly controlled billet temperatures increased adhesion between the forging and tool surface, causing process resistance, billet sticking, and accelerated tool degradation. Additional challenges were noted in tool preheating, where non-uniform heating and inaccurate temperature assessment compromised early tool performance. Measurement errors associated with thermal imaging, particularly due to thermal reflections in robotic gripper monitoring, led to overestimated temperatures and overheating of gripping elements, impairing forging manipulation accuracy. The results emphasize that effective temperature measurement management, including cross-validation of methods, is crucial for assessing tool condition, enhancing process reliability, and preventing premature failures in hot forging operations. Full article

In this study, a BTG–15kW high-frequency induction heater was utilized to fabricate composite coatings of Ni-WC-CeO₂ with varying CeO₂ content on the surface of ASTM A36 steel substrates via induction cladding. The effects of CeO₂ content on the phase composition, microstructure, elemental distribution, cross-sectional microhardness, surface hardness, Rockwell hardness, wear resistance, and wear scar morphology of the composite coatings were systematically examined using XRD, SEM, EDS, microhardness testers, Rockwell hardness testers, friction and wear testing machines, OM, and stylus profilers. The aim was to identify the optimal CeO₂ content for enhancing coating performance. The results indicated that the incorporation of CeO₂ promotes elemental inter-diffusion both within the coating and between the coating and the substrate, facilitates the dispersion of WC, and enhances the cross-sectional microhardness and wear resistance of the coating. However, excessive CeO₂ content did not lead to further improvement, suggesting the presence of an optimal concentration. Among the compositions studied, the coating with 0.5% CeO₂ exhibited minimal internal defects, pronounced elemental inter-diffusion, uniform WC, the highest cross-sectional microhardness and surface hardness, and the second-highest wear resistance, identifying this composition as the most effective for achieving superior coating performance. Full article

This paper presents a post-forming technique utilising both induction heating and rotary draw bending (RDB) for carbon fibre-reinforced polyetherentherketone (CF/PEEK) tubular structures. Existing post-forming techniques are unable to form CF/PEEK tubes due to the lack of a suitable mandrel material to provide internal support to the tube while withstanding high heat from melting the PEEK matrix during forming. This is addressed by using a steel spring mandrel in the tube induction heating process. In this study, four sets of [±60°]₄ CF/PEEK tubes were formed using an induction heater-incorporated RDB setup into 45°, 90°, 135°, and 180° bends with a bending ratio of 2. Optical characterisation was performed to analyse tube fibre angle changes. A post-forming fibre angle prediction model previously derived for CF/polyamide 6 tubes was validated for its application in predicting fibre angle changes for CF/PEEK tubes by comparing the prediction with the characterised results. Full article

In order to optimize the application effect of induction heating (IH) tundishes, a four-channel IH tundish is taken as the research object. Based on numerical simulation methods, the influence of different relative placement angles of induction heaters and channels on the electromagnetic field, flow field and temperature field of the tundish is investigated. We focus on comparing the magnetic flux density (B) and electromagnetic force (EMF) distribution of the channel. The results show that regardless of the relative placement angle between the heater and the channel, the distribution of B in the central circular cross-section of the channel is eccentric. When the heater rotates around channel 1 towards the bottom of the tundish, the distribution of B in the central circular cross-section of the channel changes from a horizontal eccentricity to a vertical one. Through the analysis of the B contour in the longitudinal section of the channel, the difference in effective magnetic flux density area (ΔA_B) between the upper and lower parts of the channel can be obtained, thereby quantitatively analyzing the distribution of B in this section. The distribution pattern of ΔA_B is consistent with the distribution pattern of the electromagnetic force in the vertical direction (F_Z) of the channel centerline. The ΔA_B and F_Z of channel 1 gradually increase as the heater rotates downwards, while those of channel 2 reach their maximum value at a rotation angle of 60°. Compared to the conventional placement, when the heater rotation angle is 60°, the outlet flow velocities at channel 1 and channel 2 decrease by 15% and 12%, respectively. However, the outlet temperature at channel 2 increases by 1.96 K, and the molten steel flow at the outlet of channel 1 and channel 2 no longer exhibits significant downward flow. This shows that when the heater rotation angle is 60°, it has a dual advantage. On the one hand, it is helpful to reduce the erosion of the molten steel on the channel and the bottom of the discharging chamber, and on the other hand, it can more effectively exert the heating effect of the induction heater on the molten steel in the channel. This presents a new approach to enhance the application effectiveness of IH tundish. Full article

Induction-heating graphitization furnaces are widely used to produce high-purity graphite products due to their high heating rate, high-limit temperatures, safety, cleanliness, and precise control. However, the existing induction-heating systems based on copper coils have limited energy efficiency. This paper proposes a new induction-heating graphitization furnace based on graphene coils. Due to the excellent high-temperature resistance of the macroscopic graphene material, the coil can be placed closer to the graphite heater, which improves the electromagnetic efficiency; the coil itself does not need to pass cooling water, which reduces the heat loss of the furnace and ultimately results in a higher energy efficiency of the induction furnace. In this paper, a numerical model of the induction-heating process is established and verified, the temperature-field and electromagnetic-field distributions of the heating process are analyzed by using the model, and the energy balance calculations are performed for the original furnace and the new furnace. Through a comparison, it was found that the new furnace possesses an electromagnetic efficiency of 84.87% and a thermal efficiency of 20.82%, and it can reduce the energy consumption by 33.34%, compared with the original furnace. In addition, the influence of the coil parameters on the performance of the induction furnace is discussed. By changing the coil conductivity, the induction furnace can achieve an energy efficiency of 17.76%–18.11%. This study provides new ideas for the application of macroscopic graphene materials in high-temperature induction heating. Full article

Composite booms for solar sails have been prototyped by using innovative smart materials. Shape memory polymer composites (SMPCs) have been manufactured by interposing SMP layers between carbon-fiber-reinforced (CFR) plies. A polyimide membrane has been embedded into the CFR-SMPC frame of the sail during lamination. The sail’s size has been limited to 250 × 250 mm² to allow its testing on Earth. The feasibility of large sail deployments has been shown by prototyping small CFR-SMPC elements to insert only in the folding zones. Numerical simulation by finite element modeling allowed for predicting the presence of wrinkles close to the frame’s vertexes in the cases of large sails under solar radiation pressures. Nevertheless, the frame’s configuration, with SMPC booms at all the edges of the sail membrane, seems to be suitable for drag sails instead of propulsion. On-Earth recovery tests have been performed on 180° folded sails by using flexible heaters. After an initial induction time, the maximum rate was reached with a following drop. In the case of two heaters per folding zone, the angular recovery rate reached the maximum value of about 30 deg/s at the power of 34 W, and full recovery was made in 20 s. Full article

The energy efficiency of supplies is crucial for the energy economy. The development of new and more efficient air heaters is a relevant topic for various industrial applications. In the formulation of air heating using a novel and flexible electromechanical system that accomplishes heating air to varying temperatures, this study examines the efficacy of using induction heating as a fundamental component of air heating systems and focuses on the effective heating of moving metal parts by electromagnetic coupling, thereafter transmitting the generated heat to the experimental facilities. The study delved into an exploration of numerous factors within a closed system, encompassing aspects such as area, temperature, and energy. Using a full-bridge ZVS circuit with an inductive coil design, fan speed variations and temperature measurements were systematically carried out to investigate the impact of induction heating on temperature changes within the given experimental setups. The results of an experiment conducted in a half-cubic-meter enclosed environment reveal significant temperature fluctuations with the varying velocities of moving metal elements, presenting a maximal rate of 17.7 degrees Celsius per hour and an efficiency factor of 64.15%. With continued refinement, this innovative technology has the potential to become an energy-efficient alternative to conventional heating techniques for a variety of applications, including industrial operations and residential heating. Full article

Ice accumulation on the surface of aircraft is a serious threat to flight safety and a fatal factor causing air accidents. However, traditional aircraft deicing methods no longer meet the requirements of safe flight due to changes in aircraft structural materials. In recent years, the application of carbon fiber-reinforced polymer (CFRP) materials in the aviation structure industry has increased. In this study, we demonstrate an economical, easy-to-prepare, and pollution-free approach to deice an aircraft through induction heating. The nickel-coated carbon fiber-reinforced polymer used as the induction heater for aircraft deicing is obtained by electroless nickel plating on the surface of the CFRP. The result shows that it takes just 110 s to achieve a temperature of 205 °C on the nickel-plated CFRP when the input voltage is 30 V, as well as melting the ice layer with a thickness of 30 mm, while the temperature of this material can reach up to 81 °C by electric heating when the input voltage is 1.5 V. Meanwhile, the nickel-plated CFRP exhibits good repeatability during the induction heating. Based on the excellent electrothermal properties, the nickel-plated CFRP polymer shows a prominent deicing ability, which provides a promising strategy for the deicing of aircraft. Full article

This paper focuses on the effect of rapid annealing on Non-Grain Oriented Electrical Steel (NGO) in terms of microstructure, mechanical properties, and magnetic properties. The Ultra-Fast Heating (UFH) tests were performed by a transversal induction heater on NGO electrical steel samples (cold rolled down to 0.5 mm), varying the heating power (80 kW and 90 kW) and the speed of the strip through the induction heater. This allowed us to exploit heating rates (HR) in the range of 200–300 °C/s and targeting peak temperature (T_peak) up to a maximum of 1250 °C. The comparison between the microstructure as obtained by conventional annealing and the ultra-fast heating process highlights a clear effect in terms of grain size refinement provided by the UFH. In particular, the average grain size as obtained by UFH ranges two/three times lower than by a conventional process. The results show the possibility of applying UFH to NGO steels, targeting mechanical properties such as those obtained by the standard process, combined with the benefits from this innovative heat treatment in terms of green energy and the minimization of CO₂ emissions. Magnetic characterization performed by a single sheet tester (30 × 90 mm) showed that the values of core losses are comparable with conventional NGO grades. Full article

The traditional sintering of metallic components shaped via Material Extrusion Additive Manufacturing (MEAM) is a time-consuming process that involves sophisticated energy-intensive heating systems. This work describes a novel induction heater capable of efficiently tailoring temperature profiles to densify MEAM powder compacts. In situ sintering within the same device is achieved indirectly by heating a graphite crucible, whereby the heater is based on an inverter with a half-bridge topology using the Zero-Voltage Switching (ZVS) technique. The system comprises a bank of capacitors that, in conjunction with a work coil, form a parallel-topology resonant circuit. This design allows the inverter to be used as a current amplifier, thereby increasing its efficiency to deliver an output power of up to 5 kW. The device operates at a 62.86 kHz resonant frequency, achieving a 2.01 mm penetration depth and a 1365.7 °C crucible temperature with only 1.313 kW of consumption, providing an increase in efficiency compared to other low-cost systems. Equipped with a feedback circuit, it offers five distinct control techniques that enable the self-tuning of the crucible temperature. The results indicate that the Cohen–Coon tuning method is more robust compared to the Ziegler–Nichols, damped, no overshoot, and mixed techniques. Sintering with this novel induction heater provides an alternative method for reducing the processing times for MEAM geometries, paving the way for increased efficiency and reduced energy consumption. Circuit diagrams, simulations, and experimental data on the temperature, time, and output voltage are provided in this article. Full article

Heating induction is a new environmentally friendly, energy-saving technology that offers a more effective performance than other common heaters. The energy-use efficiency of an inductor circuit is greater than 80 percent, while a biomass tank and tungsten coil have 70 percent and 51.8 percent efficiency, respectively. This method also produces more heat than any other forms of heating using gas or coal. The induction heating method has attracted significant interest and has seen application worldwide. Based on this important source of heating, we have designed and developed a large induction-heating machine with high energy to heat up a tank directly. The aim is to degrade organic waste as much as possible and convert it into an effective fertilizer by adding mesophilic microorganisms; the fertilizer transforming process takes no more than 24 h. The tank featured in our design has a 100-cm radius and is 155 in length; this is very large. The aim of this process is to reduce the amount of organic waste and thereby provide environmental benefits. To this end, we have designed a large, high-energy induction-heating machine (approximately 9.6 kilowatt) and used two machines in order to appropriately heat the tank for a large amount of organic-waste degradation. This research can be effectively applied to many heating methods in industry. Full article

Very high viscosity significantly impacts the mobility of heavy crude oil representing difficulties in production and a decrease in the well’s efficiency. Downhole electric heating delivers a uniform injection of heat to the fluid and reservoir, resulting in a substantial decrease in dynamic viscosity due to its exponential relationship with temperature and a drop in frictional losses between the production zone and the pump intake. Therefore, this study predicts temperature and viscosity profiles in heavy oil-production wells implementing a downhole induction heater employing a simplified CFD model. For the development of the research, the geometry model was generated in CAD software based on the geometry provided by the BCPGroup and simulated in specialized CFD software. The model confirmed a 46.1% effective decrease of mean 12° API heavy-oil dynamic viscosity compared with simulation results without heating. The developed model was validated with experimental data provided by the BCPGroup, obtaining an excellent agreement with 0.8% and 15.69% mean error percentages for temperature and viscosity, respectively. Furthermore, CFD results confirmed that downhole electrical induction heating is an effective method for reducing heavy-oil dynamic viscosity; however, thermal effects in the reservoir due to heat penetration were insignificant. For this study, the well will remain stimulated. Full article

This paper presents the results of computational and physical studies on the production of corium and its retention in an MR’s melt trap of the Lava-B facility. A feature of the Lava-B facility used in the IAE NNC RK to study the processes occurring during a severe accident at a nuclear reactor, is the separation of the stages of the reactor core corium formation and its interaction with structural materials. The melting of materials takes place in an induction furnace with a hot crucible, after which it moves to a melt receiver (MR) in which the test object is located. In the case of studies of processes occurring outside the reactor vessel, this is a special trap, which is placed in the inductor to simulate decay heat. However, based on the conservative computational estimates, it was found that the inductor power in the MR can be sufficient to directly produce, melt, and, subsequently, maintain the corium in the liquid phase. In this regard, in order to optimize the experiments under controlled conditions, the authors came up with the idea to experimentally test the possibility of producing corium by induction heating directly in the MR’s melt trap. In addition, according to the authors, this method would obviate the problem of corium contact with the carbon environment of the melting furnace of the Lava-B facility. Previously, burden heating simulating corium was modeled on the computer using available parameters of the MR’s induction heater. Based on the numerical experiment, the conditions for physical modeling of the corium production in the MR’s melt trap were established. An analysis of the physical modeling showed that during the burden heating in the melt trap, its metal components became liquid, thus, forming a melt pool. However, in terms of this design of the trap, there were problems associated with the complete melting of all corium components, as well as with the integrity of the experimental device when forming the corium pool and during the actual physical modeling. Full article

The development of energy-efficient Power-to-Heat (PtH) technologies with high power density on a utility scale is a key element in the future of flexible energy systems. Although existing solutions for electric flow heaters (EFH) based on resistance heating have a high efficiency, the process outlet temperature and power output are limited by the lifetime of the contact heating elements. Inductively heated packed bed heaters can achieve higher gas outlet temperatures with a higher power density, which is essential for an efficient process. This paper focuses on the modeling, experimental validation and numerical analysis of inductively heated pebble bed gas heater. Foremost, a model that is based on a 3D finite volume method approach is introduced. After that, an experimental setup for different sphere arrangements is used to obtain results for concept verification and model validation. With the model validated, the design space for the PtH concept is investigated by varying the heat transfer area and material properties of the pebble bed. Design solutions with high energy efficiency above 90% and power density over 5.5 MW/m³ are presented for magnetic as well as non-magnetic materials at laboratory and utility scale. Full article

Avoiding loose powders and resins, material extrusion additive manufacturing is a powerful technique to produce near-net shape parts, being a cheap and safe alternative for developing complex industrial-grade products. Filaments embedded with a high packing density of metallic or ceramic granules are being increasingly used, resulting in almost fully dense parts, whereby geometries are shaped, debinded and sintered sequentially until the completion of the part. Traditionally, “brown” debinded geometries are transported to conventional furnaces to densify the powder compacts, requiring careful tailoring of the heating profiles and sintering environment. This approach is decoupled and often involves time-consuming post-processing, whereby after the completion of the shaping and debinding steps, the parts need to be transported to a sintering furnace. Here, it is shown that sintering via indirect induction heating of a highly filled commercially available filament embedded with stainless steel 316L powder can be an effective route to densify Fused Filament Fabricated (FFF) parts. The results show that densities of 99.8% can be reached with very short soaking times, representing a significant improvement compared to prior methods. A hybrid machine is proposed, whereby a custom-built machine is integrated with an induction heater to combine FFF with local indirect induction sintering. Sintering in situ, without the need for part transportation, simplifies the processing of metal parts produced through material extrusion additive manufacturing. Full article