Papers by Keyword: High Frequency Induction Heating

Abstract: Induction heating is being actively studied, and High frequency induction heating (HFIH) is widely used for various industrial applications. The reason for highlighting induction heating is that it has many advantages compared with previously used heating methods. The performance of HFIH is governed by a number of variables, including the applied frequency and power, shape of the coil, and duration of the process. We assumed that two of these variables are dominant. The first variable is the shape of the coil. The second variable is the frequency related to the skin effect. We found the optimal hardening conditions by changing these variables. The HFIH process was simulated using FEM and compared with results from experiments. We believe that the results of this study will be helpful for users of HFIH in the near future.

Abstract: Line heating-induced deformation behavior of an SS400 thick plate was investigated through both numerical analysis and experimental counterpart by applying induction heating (IH) as a heat source. The drastic increase of temperature gradient upon increasing input power could mainly be predicted by numerical analysis, which attributes to the amount of permanent bending deformation of the thick plate. After plotting the amount of vertical deformation as a function of various positions from top surface of the plate, we found that the higher input power, the more thermomechanical deformation can be generated, regardless of the purposed doubly curved shapes such as concave and saddle-type plates. Also there is good agreement between the numerical analysis and experimental measurement in terms of the transverse curvature.

Abstract: The 2Cr13 axle sleeve, used in N52 water pumps, suffered wear after being tested for a relatively short time and fractured when it was beat under the dynamic load. Optical metallographic microscopy, scanning electron microscopy (SEM) and Vickers hardness tester for the fractured 2Cr13 axle sleeve were used to determine the most probable causes of the failure. The results showed that the failure was mainly due to the inappropriate technological parameters of high frequency induction heating and a large amplitude rotor vibration. Meantime, cracks were easily found not only close to the frayed surface but also in the inner part contributed to the inappropriate parameters. Finally, the proper protections were advised to be used for preventing this type of failure for the axle sleeve from happening again in the further.

Abstract: The HTPB-coated aluminum nanopowders were prepared by using horizontally-mounted kneading machine. The HTPB-coated aluminum nanopowders were characterized by TEM, XRD and FTIR. The exothermic characterization of the HTPB-coated aluminum nanopowders was analysized by simultaneous TG-DSC. The results show that the HTPB-coated aluminum nanopowders have a core-shell structure and the release heat enthalpy in pure oxygen is 4.954KJ/g at 542.7°C. The stability of HTPB-coated aluminum nanopowders excelled Al2O3-passivated aluminum nanopowders due to the hydrophobic nature of HTPB and the hydrophilic nature of Al2O3.

Abstract: The contribution deals with the initial design and numerical simulation of brazing process for components of solar collectors from copper-brass combined materials by the use of CuP7 brazing alloy with application of induction heating. The purpose of the contribution is to evaluate the suitability of designed inductor and its operation frequency for the given application on the basis of coupled numerical analysis of electro-magnetic and thermal fields by the ANSYS software. The attained results confirmed that using suggested arrangement of induction heating it is possible to ensure the brazing alloy melting and the development of a sound joint without undesirable overheating of brazed components or surface melting of brass flange. When increasing the frequency, the heating period is shorter but the maximum temperature of the brass component slightly increases.

Abstract: Pure Al2O3/AlB12/Al composite ceramic powders have been synthesized using high frequency induction heating method. This method starts from Al and B2O3 powder mixtures, after which Al2O3/AlB12/AlN composite ceramics were fabricated by hot-press sintering at 16000C for 2h under the protection of a N2 atmosphere. The bending strength and the fracture toughness of the ceramics were measured by the three-point bending method and the indentation fracture method, respectively. The results show that the pure Al2O3/AlB12/Al composite ceramic powders can be successfully synthesized by high frequency induction heating method. Al2O3 and AlB12 phases were formed by the liquid-liquid reaction mechanism and the liquid-solid reaction mechanism, respectively. The bending strength and the fracture toughness of the Al2O3/AlB12/AlN composite ceramics were 549.48MPa and 5.96MPa.m1/2, respectively. These values are 56.99% and 49% greater than those of the pure Al2O3 ceramic (350MPa and 4MPa.m1/2).

Abstract: The parts manufactured by die casting process usually contain liquid segregation and porosities. To solve these problems, the semi-solid forming process has been applied. The process enables material in the semi-solid state to be completely filled, and parts with the complicated shape to be fabricated by applying relatively low pressure. This process is necessary in order to control the microstructure of the billet as well as to achieve the desired semi-solid billet state. In this study, a horizontal high-frequency induction heating device which can be fabricated by semi-solid forming irrespective of a billet's size was developed. A globular structure of the reheated billet and a billet's temperature distribution during the reheating process for A356 were investigated.