Effect Of Induction Heating Research Articles

Effect of induction heating on fatigue life of drive plate for dual mass flywheel

A dual mass flywheel has positive effects on noise and vibration problems, but there are still difficulties securing sufficient component durability during the development process to increase the output. In this study, the fatigue life of a drive plate, a component in the power transmission path that is often fractured by cyclic loading, is evaluated in relation to heat treatment, and the effect of heat treatment on the fatigue life is studied. For this purpose, a fatigue test and rig test are conducted on both the raw material and heat-treated material of the drive plate. Based on the fatigue material properties obtained from the fatigue tests and the boundary conditions of the rig test, a fatigue analysis is conducted to predict the fatigue life. The heat-treated material has a fatigue life five times longer than the raw material in both the rig test and fatigue analysis. The fatigue life evaluation method is validated through a comparison of the life predicted by the fatigue analysis and the test results of the rig test.

Thermally-assisted end milling of titanium alloy Ti-6Al-4V using induction heating

Titanium and its alloys are considered as difficult-to-cut materials due to their inherent properties, such as low thermal conductivity, high cutting temperature, high chemical reactivity and strong adhesion between cutting tool and work material. This paper presents the benefits of thermally assisted machining on machinability improvement in end-milling of titanium alloy by utilising induction coil heating. The effect of online induction heating on the machinability (cutting force, tool life, vibration, and metal removal rate) are widely investigated. End milling tests were conducted on a vertical machining centre. Titanium alloy Ti-6Al-4V bar was used as the workpiece. Machining was performed with a 20 mm diameter end-mill tool holder fitted with a polycrystalline diamond (PCD) inserts. Flank wear was considered as the criterion for tool life and the wear was measured using a Hisomet II toolmaker’s microscope. The tool life tests were conducted until the flank wear exceeded 0.30 mm. Cutting force measurements were conducted using Kistler rotating cutting forced dynamometer. Vibration during cutting was captured using an online vibration monitoring system. The results lead to conclusions that thermally assisted machining significantly increases the tool life, reduces the vibration and cutting force, and increase the metal removal rate.

Effect of a SiO2 coating on the magnetic properties of Fe3O4 nanoparticles

In this work the effect of a SiO2 coating on the magnetic properties of Fe3O4 nanoparticles obtained by the sol–gel method is analyzed. Two sets of samples were prepared: Fe3O4 nanoparticles and Fe3O4@SiO2 core–shell composites. The samples display the characteristic spinel structure associated with the magnetite Fe3O4 phase, with the majority of grain sizes around 5–10 nm. At room temperature the nanoparticles show the characteristic superparamagnetic behavior with mean blocking temperatures around 160 and 120 K for Fe3O4 and Fe3O4@SiO2, respectively. The main effect of the SiO2 coating is reflected in the temperature dependence of the high field magnetization (μ0H = 6 T), i.e. deviations from the Bloch law at low temperatures (T < 20 K). Such deviations, enhanced by the introduction of the SiO2 coating, are associated with the occurrence of surface spin disordered effects. The induction heating effects (magnetic hyperthermia) are analyzed under the application of an AC magnetic field. Maximum specific absorption rate (SAR) values around 1.5 W g−1 were achieved for the Fe3O4 nanoparticles. A significant decrease (around 26%) is found in the SAR values of the SiO2 coated nanocomposite. The different heating response is analyzed in terms of the decrease of the effective nanoparticle magnetization in the Fe3O4@SiO2 core–shell composites at room temperature.

Surface Integrity in Hot Machining of AISI D2 Hardened Steel

This study presents experimental results of machined surface integrity of die material (AISI D2 hardened steel) when hot machining (induction heating) assisted end milling using coated carbide is applied. The aim of this work was to study the influence of induction heating temperature, cutting speed, and feed on the effects induced by hard milling on surface integrity (microhardness and work-hardening). Microhardness was measured to observe the distribution of the hardness beneath the surface and to determine the effect of induction heating on the micro-hardness distribution and work-hardening phenomena. The behaviour of microhardness induced in the subsurface region when end milling under room and induction heating cutting conditions using coated carbide inserts was also investigated. The surface integrity and subsurface alteration have been investigated by employing scanning electron microscope (SEM) and Vickers microhardness tester.

Analysis of heating effects (magnetic hyperthermia) in FeCrSiBCuNb amorphous and nanocrystalline wires

The induction heating effects in amorphous and nanocrystalline wires, Fe73.5-xCrxSi13.5Cu1B9Nb3 (x = 3, 7, and 10), are analyzed in this work. In these alloys, the Curie temperature of the amorphous phase, TC, can be tailored through the Cr content of the alloy or the volume crystalline fraction after nanocrystallization. Four samples were selected; amorphous with x = 0 and 10 and nanocrystalline x = 7 with different crystalline fractions. The Curie temperature of the residual amorphous phase, TCa, was experimentally determined by the temperature dependence of the self-inductance of the samples. The analysis of the frequency dependence of the complex magnetic susceptibility enabled the estimation of the magnetic power losses in the samples. The heating effects on the wires were analyzed under the application of an ac magnetic field employing a home-made hyperthermia set-up. A single piece of a wire was immersed in a water bath (initial temperature from 291 K to 325 K) and subjected to the ac magnetic field. The specific absorption rate (SAR) was estimated through the initial slope of the temperature increase as a function of time. Maximum SAR values were obtained in the amorphous sample (x = 3) with the highest TC and enhanced magnetic power losses. In the nanocrystalline samples (x = 7), the detected heating effects above TCa are interpreted as a consequence of the magnetization process of the ferromagnetic grains. However, in spite of the low SAR displayed by the amorphous wire with TC ≈ 300 K (x = 10), interesting self-regulated characteristics are observed in this sample.

Magnetic induction heating of FeCr nanocrystalline alloys

In this work the thermal effects of magnetic induction heating in (FeCr)73.5Si13.5Cu1B9Nb3 amorphous and nanocrystalline wires were analyzed. A single piece of wire was immersed in a glass capillary filled with water and subjected to an ac magnetic field (frequency, 320kHz). The initial temperature rise enabled the determination of the effective Specific Absorption Rate (SAR). Maximum SAR values are achieved for those samples displaying high magnetic susceptibility, where the eddy current losses dominate the induction heating behavior. Moreover, the amorphous sample with Curie temperature around room temperature displays characteristic features of self-regulated hyperthermia.

Exploratory study of copper particles electrodeposition on nickel by induction heating

Copper and the oxides which are spontaneously formed on its surface have numerous interesting properties that can be exploited in fields such as catalysis, gas sensing, antimicrobial activity, etc. Furthermore, metallic nanoparticles (NPs) have many size-dependent properties such as a large surface area to volume ratio that can enhance these copper/copper oxides properties. This work aims to highlight the beneficial effect of induction heating versus conventional heating on the electrodeposition of copper particles on nickel substrates. We showed that in temperature-equivalent conditions, conventional heating leads to a low coverage of the Ni electrode with weakly adherent copper microparticles (these particles having a very large size distribution and uncontrolled morphology) while induction heating leads to a high coverage of the surface with copper nanoparticles (these particles having a sharp unimodal size repartition and a truncated octahedron/octahedron shape exposing mainly (111) facets). Furthermore, while no crystalline copper oxide could be highlighted for copper nanoparticles electrodeposited at room temperature, induction heating leads to the formation of a crystalline Cu2O shell that could have interesting catalytic properties, among others.

20803 低周波誘導加熱における被加熱材の熱挙動解析(一般講演 熱流体)

Induction heating is very high efficiency and safety electrical heating method. The effect of induction heating relies on the magnitude of heating frequency. In low-frequency induction heating, core part of pan's bottom generates heat because of skin effect. It is different from surface heating of high-frequency, and enables near-uniform heating. Induction heating is direct heating, so it mainly has effect of conduction. So part of pan except heating part is not heating very much. Therefore it is very important to design and plan for pan and induction heater to gain the maximum effects. In this study, by numerical analysis of thermal behavior of water in various structures and materials of pans, appropriate condition of low-frequency induction heating was led.

Diffusion treatment of Ni–B coatings by induction heating to harden the surface of Ti–6Al–4V alloy

Electroless nickel–boron coatings on Ti–6Al–4V alloy were obtained by immersion in nickel chloride aqueous solutions with sodium borohydride. The diffusion treatments were carried out by induction heating using a superficial magnetic field intensity (current in the coil) that allows to achieve a surface temperature of 1020 °C in 100 s. The effect of induction heating on microstructure and mechanical properties of the Ni–B coated samples were evaluated by SEM, energy dispersive X-ray spectroscope (EDS), wavelength-dispersive spectrometry (WDS), glow discharge optical spectrometer (GDOS) and microhardness testing and the results were compared with those obtained previously by heat treatments in oven at 800 °C for 40 h. Surface hardness higher than 900 HV 100 and depth of hardening thicker than 300 μm were achieved by diffusion of the Ni–B layer carried out by induction heating.

The Targeting Magnetic Induction Heating of Nano-Carbon Iron Composite

A nano-carbon and iron composite--carbon coated iron nanoparticles produced by carbon arc method can be used as a new kind of magnetic targeting and heating drug carrier for cancer therapy. It presents an special nanostructure of iron nanoparticles in inner core and nano-carbon shells outside. The nano-carbon shells have a high drug adsorption ability because of its high surface area and its inner core has great effect of targeting magnetic heating. Magnetic induction heating effect of pig liver injected mixed liquids with different concentration carbon coated iron particles in physiological saline indicates that the more quantity of nanoparticles used, the higher temperature it is. Magnetic induction heating effect of the pig liver was compared in the case of filling method and injection method (both were containing 0.3g carbon coated iron nanoparticles). The iron nanoparticle in its inner core has good effect of magnetic induction heating, the temperature can go up to 51 °C in the case that carbon coated iron nanoparticles mixed with physiological saline were distributed uniformly in pig liver. And the temperature can go up to 46°C in the case that carbon-coated iron nanoparticles was injected in a certain section of pig liver. It is obvious that injected one is much better than that of filled, but they are all enough to kill the cancer cells.

Influence of Some Parameters on the Effectiveness of Induction Heating

We have investigated the effectiveness of heating conductive plates by induction in low frequencies analytically and numerically, in relation to the shape of the plate, the area of the region exposed to the magnetic flux, and the position of the exposed region with respect to the center of the plate. We considered both uniform and nonuniform magnetic fields. For plates with equivalent area exposed to the same uniform magnetic flux, the one with the most symmetrical shape is heated most effectively. If a coil is employed for the excitation, the results depend on the shape of the plate, the shape of the coil section, and the coil lift-off. When only the central region of a plate is exposed to a variable magnetic flux, there is a specific value of the exposed area for which the power dissipated in the plate material reaches a maximum. The most effective heating of a plate partially exposed occurs when the axis of the exciting coil is at the plate center.

The effect of drawing velocity and phase transformation on the structure of directionally annealed iron

Undeformed iron bars were directionally annealed under various processing parameters. Columnar grains having an aspect ratio as high as 50 were produced at optimum processing conditions of a hot zone temperature of 850 °C, a 200 °C/cm temperature gradient and a drawing velocity of 1 μm/s. Equiaxed grains were formed both when the drawing velocity was low, and when it exceed the maximum growth rate of grains. The ferrite to austenite phase transformation hindered the columnar grain growth. A novel microstructure with columnar grains in the outer region, whose longitudinal axis parallels to the drawing direction, and fine equiaxed grains at the center of the specimen was observed. The skin effect of high frequency induction heating during the directional annealing was used to explain the formation of this novel microstructure.

On the selective magnetic induction heating of micron scale structures

Magnetic induction heating is a promising heating approach for MEMS processes and devices. This study has discussed the scale effect of induction heating for thin-film microstructures through analytical and experimental means. The results show that the temperature increase varies with the in-plane surface area of the microstructure and the relative permeability of thin-film materials. Moreover, the shape of the microstructure also leads to the difference of temperature increase. In applications, localized heating and various temperature regions can be simultaneously achieved on the substrate by applying an external high-frequency magnetic field.

超急速短時間加熱焼入れしたフェライト地の球状黒鉛鋳鉄の疲労強度

To clarify the effects of Super Rapid Induction Heating and Quenching (SRIHQ) on fatigue properties of Ferritic Ductile Cast Iron (FDI), rotational bending fatigue tests were carried out on specimens treated with four types of heating cycle. Results showed that; (i) the SRIHQ process generated a thin dark gray area around the graphite. This dark area was composed of a martensite structure (ringed martensite). (ii) The ringed martensite generated a compressive residual stress field at the surface hardened layer. Two types of compressive residual stress generative mechanisms were observed. One was a microscopic residual stress generative process due to the formation of ringed martensite and the other was a macroscopic residual stress generative process due to the expansion of the surface hardened layer. (iii) The fatigue strength of SRIHQ treated FDI specimen was higher than that of the untreated one. This was because the compressive residual stress field generated by the ringed martensite suppressed initiation and propagation of fatigue cracks.

Effects of induction heating on temperature distribution and growth rate in large-size SiC growth system

For design of large-size silicon carbide (SiC) growth system, it is essential to choose induction heating parameters such as frequency and power. Modeling and simulations have been performed on a 2-in SiC growth system to investigate the effects of induction heating on the temperature distribution and growth rate. For frequencies in the range of 4–20 kHz, it is found that the maximum temperature and growth temperature in the growth system increase with the frequency while keeping the same current in the induction coil. For lower frequency induction heating, it is difficult to achieve high temperatures, which may be essential for the growth of high-quality crystals. It is observed from experiments that the quality of SiC crystals is related to the growth temperature. The SiC growth rates as a function of system pressure for different frequencies have been obtained by the theoretical method.

Fatigue Strength of Ferritic Ductile Cast Iron Hardened by Super Rapid Induction Heating and Quenching

To clarify the effects of Super Rapid Induction Heating and Quenching (SRIHQ) on fatigue properties of Ferrite Ductile Cast Iron (FDI), rotational bending fatigue tests were carried out on specimens treated with four types of heating cycle. Results showed that; (i) the SRIHQ process generated a thin dark gray area around the graphite. This dark area was composed of a martensite structure (ringed martensite). (ii) The ringed martensite generated a compressive residual stress field at the surface hardened layer. Two types of compressive residual stress generative mechanisms were observed. One was a microscopic residual stress generative process due to the formation of ringed martensite and the other was a macroscopic residual stress generative process due to the expansion of the surface hardened layer. (iii) The fatigue strength of SRIHQ treated FDI specimen was higher than that of the untreated one. This was because the compressive residual stress field generated by the ringed martensite suppressed initiation and propagation of fatigue cracks.

Mathematical model of influence of rapid induction heating on nucleation and growth of precipitates

A mathematical model of the influence of rapid induction heating on the nucleation and growth of secondary phases in diffusion controlled processes has been developed. The total stress produced by the electromagnetic field and acting on the volume V of a specimen was derived and added to other external stresses applied to the system. Then, the total effective stress was introduced into mathematical equations of diffusion controlled nucleation and growth processes. In addition, the effect of rapid induction heating on the age hardening treatment of a selected cast nickel base superalloy, IN738LC, was investigated experimentally. For this purpose, two types of rapid aging with equal heating rates were applied: one treatment was induction aging and the other was salt bath aging. Microstructural characteristics of γ′ precipitates and hardening behaviour were studied by means of scanning electron microscopy (SEM), electron image analysis, transmission electron microscopy (TEM), and hardness testing. According to the results obtained, although the rates of heating in induction and salt bath aging were equal, the rates of nucleation and growth of γ′ precipitates in induction aging were much faster than those obtained in salt bath aging, especially in the first minutes of the aging process. Furthermore, the characteristics of γ′ precipitates with induction aging were more favorable than those with salt bath and normal aging. It was observed that the growth rate of γ′ in induction aging deviated considerably from the t1/3 growth law of the standard modified Lifshitz, Slyozov, and Wagner (MLSW) theory. The remarkable improvement of microstructural characteristics obtained with induction aging can be attributed to the existence of the external electromagnetic force produced by rapid induction heating.

Monitoring Density and Temperature in C/C Composites Processing by CVI with Induction Heating

Carbon/carbon composites are processed by chemical vapor infiltration (CVI) with radio-frequency inductive heating, which leads to inside-out temperature gradients, suitable for the production of homogeneously densified pieces if properly controlled throughout the whole processing. We present here a 2D axisymmetrical case where a comprehensive numerical model is tested against experimental runs. The numerical thermal model takes into account induction heating, radiative, conductive, and convective effects, intermediate regime diffusion and densification reactions in the pores, and the evolution of the porous medium. The results are the time evolution of the temperature, concentration, and composite material density field, as well as the input power necessary to ensure a given maximal temperature in the preform. Experimental data are measurements of the temperature and density fields at various infiltration stages. Comparison between experience and simulation, yielding an useful agreement, shows that porosity becomes trapped inside the preform as densification proceeds, because of the progressive lowering of the temperature gradient steepness. The discrepancies between computations and experimental data rely on the only approximate knowledge of some quantities, principally the reaction kinetics, which are currently under investigation.

Electromagnetics and coupled problems

Introduces the fourth and final chapter of the ISEF 1999 Proceedings by stating electric and magnetic fields are influenced, in a reciprocal way, by thermal and mechanical fields. Looks at the coupling of fields in a device or a system as a prescribed effect. Points out that there are 12 contributions included ‐ covering magnetic levitation or induction heating, superconducting devices and possible effects to the human body due to electric impressed fields.

Experiments and Analysis of the Effect of Local Induction Heating on Deformation

Experiments and Analysis of the Effect of Local Induction Heating on Deformation