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이경희;이병하;허원도;황우연
- 한국세라믹학회지
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- 제31권1호
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- pp.55-61
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- 1994
Mn-Zn ferrite powder was obtained by wet method that was to be coprecipitated the metal ions of Fe2+, Mn2+ and Zn2+ with alkali solution. The target composition of the ferrite powder was 52 mol% Fe2O3, 24 mol% MnO, and 24 mol% ZnO, that was based on the region of high permeability. And the other ferrite powder was prepared by the dry method that was to be mixed the metal oxides as the above chemical composition. The wet method was compared with dry method for the powder properties and the electromagnetic characteristics of sintered cores. The synthesized powder by wet method was smaller particle size, narrower particle distribution, and higher purity than that of dry method. The initial permeability of sintered sample prepared by the wet method was 14000~28000, on the other side, 9000~15500 in case of the dry method.
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Chung, Seong-Taek;Kwon, Young-Sam
- 한국분말야금학회:학술대회논문집
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- 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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- pp.493-494
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- 2006
Chip breaker of cutting tool is an important feature to enhance cutting performance. Powder injection molding process was used to produce a triangular-shape cermet grooving insert which has three chip breakers. Attrition milled cermet powders were mixed with wax-based binder system in continuous twin screw extruder. Three-plate injection mold with slide cores was used to produce injection-molded parts. After molding, solvent and thermal debinding was carried out. Sintering was conducted in a batch furnace with a graphite heater. The sintered parts satisfy the requirements of dimensional tolerances and material properties.
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노태환;최혁열;안상재
- 한국자기학회지
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- 제14권1호
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- pp.7-12
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- 2004
F $e_{73.5}$C $u_1$N $b_3$S $i_{15.5}$ $B_{7}$ 비정질 리본 합금을 490∼61$0^{\circ}C$의 온도 범위에서 열처리하고 이를 볼 밀링 하여 얻은 250∼850$\mu\textrm{m}$크기의 자성분말과 5wt%의 세라믹 절연체로 구성된 분말 코아의 자기적 특성에 열처리 온도가 미치는 영향을 조사하였다. 5$50^{\circ}C$에서 1 h동안 열처리하여 직경 11 nm의 $\alpha$-Fe상 나노 결정립 구조로 되었을 때(전기비저항은 110$\mu$Ω$.$cm)가장 높은 실효투자율 및 품질계수를 나타내었으며 그 값은 각각 125와 53이었고, 실효투자율의 경우 약 500 KHz에 이르기까지 일정한 크기를 유지하였다. 그리고 이 열처리 조건에서 230 mW/㎤(f=50 KHz, $B_{m}$ =0.1 T)의 대단히 낮은 자심손실을 나타내었다. 그러나 이 합금의 분말 코아는 종래의 분말 코아 재료(MPP,센더스트 등)에 비해 그리 우수하지 못한 직류 바이어스 특성 특히 저 자장 하에서의 낮은 퍼센트 투자율을 나타내었는데, 이는 종래의 소재와 유사한 투자율을 얻는데 너무 큰 입도의 분말이 필요한 것에 그 원인이 있는 것으로 이해되었다.
https://doi.org/10.4283/JKMS.2004.14.1.007 인용 PDF KSCI