• Journal of Magnetics
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• 제3권1호
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• pp.15-20
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• 1998

A newly designed magnetic annealing apparatus was used for the treatment of Fe-3%Si steels. With the help of this device, the effect of magnetic annealing on magnetostriction was studied in a wide spectrum of external elastic stresses. It was shown that magnetostriction properties of Fe-Si steels were improved in the compressed state through magnetic annealing, while those in the unstressed state or under tensiion were found to be practically unchanged.

• Journal of Magnetics
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• 제11권3호
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• pp.111-114
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• 2006

We electroplated copper-cobalt thin films on a silicon substrate, which had 150 nm thick copper seed layer. The adhesion between the two metallic layers could be increased by utilizing a proper organic additive, pulse plating technique, and high temperature annealing. The thin films exhibited columnar growth of the deposits and enhanced adhesion. This is attributed to the grain growth mechanism introduced by the additive and annealing.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.625-626
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• 2008

The magnetic domain-refining techniques such as ball scratching, laser irradiation and plasma have been developed to reduce the domain wall spacing and thus iron losses in Fe-3%Si grain-oriented silicon steels. In view point of magnetic properties, it was supposed that the locally residual stresses change the magnetoelastic energy of the material and thus the spacing between $180^{\circ}$ domain walls decreases in order to reduce the magnetostatic energy. The effect of laser irradiation on iron loss and magnetostriction reduction for Fe-3%Si grain-oriented steel were investigated. Since the local tensile stresses were induced at the surface of Fe-3%Si steel by the laser irradiation, the minimum iron loss caused by reducing eddy current loss was obtained in spiete of the decrease of permeability by hindering eddy current loss was obtained in spite of the decrease of permeability by hindering the domain wall movement around the induced stress field. Furthermore, the laser treated 3%Si steel has lower magnetostriction as compared to non laser-treated steel and is less sensitive to applying pre-stresses due to the volume reduction of $90^{\circ}$ domain in materials.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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• pp.93-97
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• 2001

A new compact, low-energy electron beam irradiator has been developed. The core-loss of silicon steels can be reduced by magnetic-domain refinement method. The irradiator was developed for the application of core-loss reduction using the method. The beam energy of the irradiator can be varied from 35 to 80 keV and the maximum current is 3mA. The irradiation area is designed to be $30\times30mm2$ now and will be upgraded to $30\times150mm2$ using a scanning magnet and scanning cone. The electron beam generated from 3 mm diameter LaB6 is extracted to the air for the irradiation of the silicon steels in the air. A special irradiation port was developed for this low-energy irradiator. A havar foil with $4.08{\mu}m$ thickness were used for the window and a cold air-cooling system keeps the foil structure by removing heat at the window. The irradiator system and its operation characteristics will be discussed.

• 한국전자파학회논문지
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• 제20권7호
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• pp.639-647
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• 2009

본 연구에서는 자기장 차폐를 위하여 3상 전력 케이블을 얇은 자성 판재로 둘러싸는 방법을 제안한다. 두꺼운 상용 뮤-메탈, 방향성 및 무방향성 규소 강판을 출발 재료로 하여 두께 0.1 mm의 차폐재 3종류를 제조하였다. 3상 전류일 때, 차폐재 위치의 자기장이 100 ${\mu}T$ 정도이면 뮤-메탈이 (SF<0.1) 가장 효과적이었고, 500 ${\mu}T$ 이상 이면 규소 강판이 (SF 0.3${\sim}$0.4) 더 효과적이었다. 또한, 안쪽에 방향성 규소 강판, 바깥쪽에 뮤-메탈을 함께 둘러쌀 경우 500 ${\mu}T$까지도 SF 를 0.1 이하로 할 수 있었다. 한편, 단상 전류에서는 고 투자율 소재의 적용은 오히려 자기장을 증가시키는 결과를 보였다. 이상의 결과는 자기장 강도 H의 크기에 따라 각 소재의 투자율 우열이 서로 다른 점과 이로 인해 차폐재 내에 유도되는 자기장 벡터와 원래의 자기장 벡터의 상호 상쇄 및 중첩 작용으로 설명할 수 있었다.