http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : 최혁열(H. Y. Choi) (검색결과 3 건)
- 무료
- 기관 내 무료
- 유료
-
Fe73.5Cu₁Nb₃Si15.5B7 나노 결정립 합금 분말 코아의 자기적 특성
노태환(T. H. Noh),최혁열(H. Y. Choi),안상재(S. J. Ahn) 한국자기학회 2004 韓國磁氣學會誌 Vol.14 No.1
The annealing-temperature dependence of magnetic properties in compressed powder cores being composed of ball-milled Fe_(73.5)Cu₁Nb₃Si_(15.5)B_7 alloy powders (size : 250~850 ㎛) and 5 wt% of ceramic insulators has been investigated. When annealed at 550 ℃ for 1 h and so transformed to α-Fe phase nanocrystalline structure with the grain size of 11 ㎚ (electrical resistivity : 110 μΩ·㎝), the highest effective permeability of 125 and quality factor of 53 were obtained, and the permeability persisted up to about 500 ㎑. Further the core loss measured at the frequency of 50 ㎑ and the induction amplitude of 0.1 T was very low (230 ㎽/㎤). However the dc bias characteristics was not satisfactory as compared to that of conventional powder core materials(MPP, Sendust etc.). The inferior dc bias property of Fe_(73.5)Cu₁Nb₃Si_(15.5)B_7 alloy powder cores was attributed to the fact that the size of powder was too large for obtaining the same permeability with that of conventional materials.
-
FeCuNbSiB 나노결정립 합금 분말코아의 자기적 특성에 미치는 절연체의 영향
노태환(T. H. Noh),최혁열(H. Y. Choi) 한국자기학회 2004 韓國磁氣學會誌 Vol.14 No.5
The variation of magnetic properties with insulating materials(glass frits, talc and polyamide) in compressed powder cores composed of Fe_(73.5)Cu₁Nb₃Si_(15.5)B_7 nanocrystalline alloy powders(size : 250~850 ㎛) and 3 wt% insulators has been investigated. Larger permeability was obtained at the frequency lower than 300~400 ㎑ for the powder cores including ceramic insulators(glass frits and talc) as compared to the cores with polyamide, while at higher frequency than 1 ㎒ the permeability of the former cores decreased rapidly. Further the cores with ceramic insulators showed larger core loss and smaller peak quality factor attained at lower frequency. On the contrary, the powder cores with polyamide exhibited high stability of permeabilities up to several ㎒ and superior core-loss and quality-factor properties. Moreover the de bias property was better in the wide field range for the cores having polyamide. The enhanced magnetic properties of polyamide-added cores were attributed to the more sufficient electrical insulation between magnetic particles, where the higher insulation state was considered to be obtained from the larger volume fraction of polyamide in the powder cores.
-
철계 비정질 합금 분말코아의 자기적 특성에 미치는 분말 제조방식의 영향
노태환(T. H. Noh),최혁열(H. Y. Choi) 한국자기학회 2005 韓國磁氣學會誌 Vol.15 No.3
In the fabrication process of Fe-based amorphous alloy powder cores by pulverization of the melt-spun ribbons and cold compaction, the effects of powder preparation method on the magnetic & electric properties, powder shapes and microstructure of cores have been investigated. The powder cores made by using rotor mill showed low effective permeability as compared to the cores prepared by ball milling. However the frequency dependence and quality factor properties were superior in the case of rotor-milling. Further the powders prepared by rotor mill had homogeneous and round shapes through strong shearing in the sieve ring, while the ball milled powders were inhomogeneous and relatively small. The lower permeability of the powder cores fabricated with rotor mill was considered to be due to the high internal stress occurred by very intensive shearing. Moreover the powder cores produced by rotor-milling showed lower core loss and good frequency dependence of effective permeability possibly due to the higher electrical insulation between magnetic particles. The dc bias property of the powder cores made by rotor-milling was better than the one by ballmilling.
ScienceON
DBpia연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
