scholarly journals A Rapid Thermal Nanoimprint Apparatus through Induction Heating of Nickel Mold

Micromachines ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 334 ◽  
Author(s):  
Xinxin Fu ◽  
Qian Chen ◽  
Xinyu Chen ◽  
Liang Zhang ◽  
Aibin Yang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Cooling Rate ◽  
Induction Heating ◽  
Nanoimprint Lithography ◽  
High Speed ◽  
Eddy Currents ◽  
Magnetic Hysteresis ◽  
Alternating Magnetic Field ◽  
Polymer Materials ◽  
Heating And Cooling

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.

scholarly journals The loss of energy in metal plates of finite thickness, due to eddy currents produced by alternating magnetic fields

1926 ◽  
Vol 111 (759) ◽  
pp. 604-614 ◽  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Eddy Currents ◽  
Finite Thickness ◽  
Metal Plate ◽  
The Self ◽  
Alternating Magnetic Field ◽  
Metal Plates ◽  
Alternating Magnetic Fields

The induction of eddy currents in metal plates which are subjected to alternating magnetic fields has been discussed by Clerk-Maxwell, J. J. Thomson and many others. When an alternating magnetic field is produced normal to the surface of a metal plate, eddy currents are induced at the surface of the plate, which gradually penetrate its interior, the current dying away as it penetrates more deeply into the metal. The diffusion of the currents into the plate depends upon the self-induction and resistance of the paths along which they flow, and can be calculated by the same kind of formula as is used for determining the conduction of heat through a metal slab.

scholarly journals Effect of Alternating Magnetic Field on Arc Plasma Characteristics and Droplet Transfer during Narrow Gap Laser-MIG Hybrid Welding

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1712
Author(s):  
Baihao Cai ◽  
Juan Fu ◽  
Yong Zhao ◽  
Fugang Chen ◽  
Yonghui Qin ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electron Temperature ◽  
High Speed ◽  
Stable State ◽  
Alternating Magnetic Field ◽  
Hybrid Welding ◽  
Arc Plasma ◽  
Narrow Gap ◽  
Droplet Transfer ◽  
The Magnetic Field

In this paper, the morphological characteristics of arc plasma and droplet transfer during the alternating magnetic field-assisted narrow gap groove laser-MIG (metal inert gas) hybrid welding process were investigated. The characteristics of arc plasma and droplet transfer, electron temperature, and density were analyzed using a high-speed camera and spectrum diagnosis. Our results revealed that the arc maintained a relatively stable state and rotated at a high speed to enhance the arc stiffness, and further improved the stability of the arc under the alternating magnetic field. The optimum magnetic field parameters in this experiment were B = 16 mT and f = 20 Hz, the electron temperature was 9893.6 K and the electron density was 0.99 × 1017 cm−3 near the bottom of the groove, which improved the temperature distribution inside the narrow gap groove and eliminated the lack of sidewall fusion defect. Compared to those without a magnetic field, the magnetic field could promote droplet transfer, the droplet diameter decreased by 17.6%, and the transition frequency increased by 23.5% (owing to the centrifugal force during droplet spinning and electromagnetic contraction force). The width of the weld bead was increased by 12.4% and the pores were also significantly reduced due to the stirring of the magnetic field on the molten pool.

Dynamic Interfacial Phenomena at Water-Magnetic Fluid System Subject to Alternating Magnetic Field

2016 ◽  
Vol 856 ◽  
pp. 15-20
Author(s):  
Masato Nakanishi ◽  
Seiichi Sudo ◽  
Hideya Nishiyama
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Magnetic Fluid ◽  
High Speed ◽  
Video Camera ◽  
Alternating Magnetic Field ◽  
Fluid System ◽  
Camera System ◽  
High Speed Video Camera ◽  
Rosensweig Instability

Responses of a magnetic fluid interface adsorbed on a small permanent magnet in water container subjected to an alternating magnetic field were studied with a high-speed video camera system. The directions of the external alternating magnetic field were parallel and anti-parallel to that of the permanent magnet. It was found that the interface of water-magnetic fluid responds to the external alternating magnetic field in elongation and contraction with Rosensweig instability at the interface. Frequency characteristics of the interface response of water-magnetic fluid system subjected to alternating magnetic field were revealed over a wide frequency band experimentally.

Vibration Characteristics of Magnetic Fluid Droplet Adsorbed to Magnetized Needlepoint in Alternating Magnetic Field

2012 ◽  
Vol 721 ◽  
pp. 108-113
Author(s):  
Sota Inomata ◽  
Seiichi Sudo ◽  
Hidemasa Takana ◽  
Hideya Nishiyama
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Magnetic Fluid ◽  
High Speed ◽  
Video Camera ◽  
Alternating Magnetic Field ◽  
Camera System ◽  
High Speed Video ◽  
High Speed Video Camera ◽  
Video Camera System

The dynamic behavior of a magnetic fluid droplet adsorbed to magnetized needlepoint in alternating magnetic field was studied with a high speed video camera system. The directions of alternating magnetic field were parallel and opposite to static magnetic field of magnetized needlepoint. It was found that the surface of magnetic fluid droplet responds to the external magnetic field in elongation and contraction. The frequency of magnetic fluid droplet oscillation was exactly same of the external magnetic field. The shape and instability oscillations of the magnetic fluid droplet were revealed experimentally.

scholarly journals Inductive Heating Using a High-Magnetic-Field Pulse to Initiate Chemical Reactions to Generate Composite Materials

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 535 ◽  
Author(s):  
Cordelia Zimmerer ◽  
Catalina Mejia ◽  
Toni Utech ◽  
Kerstin Arnhold ◽  
Andreas Janke ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Chemical Reactions ◽  
Induction Heating ◽  
Polymer Materials ◽  
Heating Process ◽  
Inductive Heating ◽  
Magnetic Field Pulse ◽  
Transfer Energy ◽  
Scanning Calorimetry ◽  
Field Pulse

Induction heating is efficient, precise, cost-effective, and clean. The heating process is coupled to an electrically conducting material, usually a metal. As most polymers are dielectric and non-conducting, induction heating is not applicable. In order to transfer energy from an electromagnetic field into polymer induction structures, conducting materials or materials that absorb the radiation are required. This report gives a brief overview of induction heating processes used in polymer technology. In contrast to metals, most polymer materials are not affected by electromagnetic fields. However, an unwanted temperature rise of the polymer can occur when a radio frequency field is applied. The now available high-field magnetic sources provide a new platform for induction heating at very low frequencies, avoiding unwanted thermal effects within the material. Using polycarbonate and octadecylamine as an example, it is demonstrated that induction heating performed by a magnetic-field pulse with a maximum flux density of 59 T can be used to initiate chemical reactions. A 50 nm thick Ag loop, with a mean diameter of 7 mm, placed in the polymer-polymer interface acts as susceptor and a resistive heating element. The formation of urethane as a linker compound was examined by infrared spectroscopic imaging and differential scanning calorimetry.

Remagnetization Core Losses In The Massive Amorphous FeCoYb Alloy

2017 ◽  
Vol 68 (4) ◽  
pp. 698-700
Author(s):  
Katarzyna Bloch ◽  
Marcin Nabialek ◽  
Konrad Gruszka
Keyword(s):  
Magnetic Field ◽  
Amorphous Alloy ◽  
Power Loss ◽  
Eddy Currents ◽  
Magnetic Hysteresis ◽  
Bulk Amorphous Alloy ◽  
Field Frequency ◽  
Magnetic Field Frequency ◽  
Core Losses ◽  
Additional Losses

In this paper were studied the influence of magnetic field frequency and induction on the total core power loss � which is divided into eddy current loss, hysteresis loss and anomally losses of the bulk amorphous alloy. The total core power loss of the investigated bulk amorphous alloy increases with magnetic field frequency and peak induction. It follows a power relation similar to what has been observed in classical ribbons. In the investigated alloy in addition to losses due to magnetic hysteresis and eddy currents, other additional losses are present. However additional losses, emerging simultaneously to the component associated with migration relaxations are very weakly dependent on the frequency and temperature.

Morphology and Distribution of in Al-Fe Alloy under an Alternating Magnetic Field

2007 ◽  
Vol 546-549 ◽  
pp. 933-936
Author(s):  
Yi Han ◽  
Chun Yan Ban ◽  
Shi Jie Guo ◽  
Qi Xian Ba ◽  
Jian Zhong Cui
Keyword(s):  
Magnetic Field ◽  
Cooling Rate ◽  
Lorentz Force ◽  
Low Frequency ◽  
Alternating Magnetic Field ◽  
Al Matrix

The aim of this work is to study the effect of a low frequency alternating magnetic field on morphology and distribution of A3F2 in the Al-2.89 wt.% Fe alloy. At the cooling rate of 0.05 °C/s, only Al3Fe phase was observed in the iron-containing intermetallics. It was noteworthy that, compared with the conventional solidification, the primary Al3Fe phase was refined and accumulated towards the center of the sample by applying the alternating magnetic field. This phenomenon is considered as the result of the larger Lorentz force acting on the Al3Fe phase than the Al matrix.

scholarly journals A novel circuit topology of modified switched boost hybrid resonant inverter fitted induction heating equipment

2016 ◽  
Vol 65 (4) ◽  
pp. 815-826
Author(s):  
Ananyo Bhattacharya ◽  
Kaushik Sit ◽  
Pradip Kumar Sadhu ◽  
Nitai Pal
Keyword(s):  
Magnetic Field ◽  
Energy Efficiency ◽  
Induction Heating ◽  
High Frequency ◽  
High Energy ◽  
Alternating Magnetic Field ◽  
Voltage Source ◽  
Heating Equipment ◽  
Circuit Topology ◽  
Resonant Inverter

Abstract A novel circuit topology of modified switched boost high frequency hybrid resonant inverter fitted induction heating equipment is presented in this paper for efficient induction heating. Recently, induction heating technique is becoming very popular for both domestic and industrial purposes because of its high energy efficiency and controllability. Generally in induction heating, a high frequency alternating magnetic field is required to induce the eddy currents in the work piece. High frequency resonant inverters are incorporated in induction heating equipment which produce a high frequency alternating magnetic field surrounding the coil. Previously this high frequency alternating magnetic field was produced by voltage source inverters. But VSIs have several demerits. So, in this paper, a new scheme of modified switched boost high frequency hybrid resonant inverter fitted induction heating equipment has been depicted which enhances the energy efficiency and controllability and the same is validated by PSIM.

Sign in / Sign up

Export Citation Format

Share Document