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YBa2Cu3O7-δ (YBCO) thin films were fabricated rapidly on LaMnO3/MgO/Y2O3/Al2O3/Hastelloy substrate by the self-built induction heating system. The growth rate can be more than 60 nm/s, which is much higher than the traditional Metal Organic Deposition (MOD) method. The effects of heating rate, oxygen partial pressure and growth temperature on the texture and morphology of YBCO films were studied, as well as the analysis of properties. The results of X-Ray Diffraction and Scanning Electron Microscopy demonstrated that rapid heating can effectively reduce the residual of BaCO3 particles. The faster heating rate results in a faster YBCO growth rate, easier c-axis oriented grains growth and denser morphology. Moreover, the growth temperature and atmosphere window of YBCO films were obtained in the rapid heating condition. Meanwhile, the YBCO nucleation and growth models were established. This work realized the rapid crystallization of YBCO films by induction heating system and improved understanding of the nucleation mechanism of YBCO on the flexible metal substrate with buffer layers, which is extremely attractive for the industrialization development of Fluorine Free-MOD superconducting films in the future. [ABSTRACT FROM AUTHOR]

This study reports a newly designed induction heating system for efficient, fast, and safe flow-through heating. The system has a very simple architecture, which is composed of a transmitting coil, an isolating plastic pipe, and an embedded metal shell. Wireless energy transfer from the external coil to the internal metal shell through the pipe is essential for decreasing losses. Also, a large contact surface between a fluid and the immersed shell enables rapid heat transfer. The proposed heating system was systematically investigated for different shell geometries and the results were compared with a commercially available conductive flow-through heating device. As a proof-of-concept demonstration, a prototype of the designed induction heating system was manufactured and the heating measurements were conducted with water. Power transfer efficiency of the prototyped induction heating system was measured to be 97%. The comparative study indicates that such high-efficiency induction flow-through heating system offers a great potential for replacing the conventional conductive heating device used in household applications in which the rapid and compact heating is desired. [ABSTRACT FROM AUTHOR]

Thermal nanoimprint lithography is playing a vital role in fabricating micro/nanostructures on polymer materials by the advantages of low cost, high throughput, and high resolution. However, a typical thermal nanoimprint process usually takes tens of minutes due to the relatively low heating and cooling rate in the thermal imprint cycle. In this study, we developed an induction heating apparatus for the thermal imprint with a mold made of ferromagnetic material, nickel. By applying an external high-frequency alternating magnetic field, heat was generated by the eddy currents and magnetic hysteresis losses of the ferromagnetic nickel mold at high speed. Once the external alternating magnetic field was cut off, the system would cool down fast owe to the small thermal capacity of the nickel mold; thus, providing a high heating and cooling rate for the thermal nanoimprint process. In this paper, nanostructures were successfully replicated onto polymer sheets with the scale of 4-inch diameter within 5 min.

In this study, a working coil coupled with magnetic flux concentrators for barrel induction heating in an injection molding machine was investigated. Induction heating process simulations were developed to evaluate the effects of magnetic flux concentrators to the temperature distribution at surface inside a barrel of an injection molding machine. Different pitches of magnetic flux concentrators were applied to study the uniform heating capability of induction heating system with heating coil coupled with magnetic flux concentrators via commercial software, ANSYS. Models of working coils coupled with magnetic flux concentrators were experimented to verify the simulation results. The results from simulation and experiment agreed well. Simulation results showed that, changing diameters of a barrel or varying operation frequency of induction power supply had no effect on uniform temperature distribution at the inside surface of the barrel. [ABSTRACT FROM AUTHOR]

In an injection molding machine, the conventional barrel heating system which uses resistance heating method (RH) has some drawbacks such as low heating rate, long heating time, and energy loss. With induction heating (IH) technique, the barrel can better handle almost all of these disadvantages. However, non-uniform temperature distribution on inside surface of a barrel is the main drawback of induction heaters. A working coil coupled with magnetic flux concentrators via adjustment of magnetic flux concentrator spacing to achieve uniformity of magnetic flux and temperature distribution on the inside surface of a barrel was proposed and experimented. Results showed that, when barrel was heated by induction heating method with the proposed induction heating coil, heating time to reach a specific temperature could be reduced, and heating rate increased compared to resistance heating method. With 8 mm pitch of magnetic flux concentrators on a coil, the temperature distribution was the most uniform. [ABSTRACT FROM PUBLISHER]

This paper proposes a new induction heating technology capable of controlling a precise exothermic distribution, which is termed zone-control induction heating (ZCIH). The ZCIH system consists of two or more sets of a high-frequency inverter unit and a work coil. The inverter units control the phase angle of the coil current to be in phase with each other. The ZCIH has the capability of operation with the mutual inductance, and enables locating the coils as close as possible. As a result, the ZCIH technology makes it possible to achieve rapid heating performance with extremely precise exothermic distribution. This paper presents experimental results of a 150-kW six-zone ZCIH system for semiconductor heat processing. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 171(1): 37–45, 2010; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/eej.20908 [ABSTRACT FROM AUTHOR]

Rapid thermal processing strategies, i.e. thermal histories that involve high heating rates, short times at peak temperatures, and subsequent rapid cooling by quenching, and that typically require significantly shorter total processing times than are utilized in conventional sheet steel processing, are reviewed to illustrate potential benefits and challenges for the production of new advanced high strength steel grades. A fundamental framework based on conventional induction heat treating often applied to rapidly selectively harden surfaces of steel components is highlighted to provide a basic structure for assessment of rapid thermal processing of sheet steels. Four sheet steel product groups were considered. These include dual-phase (DP) steels, quenched and partitioned (Q&P) steels, flash processed steels, and press hardened steels. In comparison to conventionally heat-treated steels, rapid processing of steels resulting in multi-constituent microstructures consisting of ferrite and martensite (DP) and also containing retained austenite (Q&P) result in enhanced strength-ductility combinations primarily due to microstructural refinement. Results indicate that flash processed and press hardening steels, both with primarily martensitic microstructures, exhibit properties largely similar to conventional quenched and low-temperature-tempered steels. • Rapid thermal processing refines heat-treated steel microstructures. • Induction and flash processing may lead to primarily martensitic microstructures. • Dual-phase and quenched and partitioned steel properties enhanced by rapid processing. [ABSTRACT FROM AUTHOR]

Thermal nanoimprint lithography is playing a vital role in fabricating micro/nanostructures on polymer materials by the advantages of low cost, high throughput, and high resolution. However, a typical thermal nanoimprint process usually takes tens of minutes due to the relatively low heating and cooling rate in the thermal imprint cycle. In this study, we developed an induction heating apparatus for the thermal imprint with a mold made of ferromagnetic material, nickel. By applying an external high-frequency alternating magnetic field, heat was generated by the eddy currents and magnetic hysteresis losses of the ferromagnetic nickel mold at high speed. Once the external alternating magnetic field was cut off, the system would cool down fast owe to the small thermal capacity of the nickel mold; thus, providing a high heating and cooling rate for the thermal nanoimprint process. In this paper, nanostructures were successfully replicated onto polymer sheets with the scale of 4-inch diameter within 5 min. [ABSTRACT FROM AUTHOR]