• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2005년도 추계학술강연 및 발표대회강연 및 발표논문 초록집
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• pp.59-60
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• 2005

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.996.1-996.1
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• 2006

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2002년도 춘계학술강연 및 발표대회
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• pp.48-50
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• 2002

No Abstract, See Full Text

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2005년도 춘계학술강연 및 발표대회강연 및 발표논문 초록집
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• pp.61-61
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• 2005

• 한국분말재료학회지
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• 제5권4호
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• pp.340-344
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• 1998

Along with the growth of conventional ferrous powder metallurgy (PM), PM of aluminum alloys has been intensively investigated in Japan. Although rapidly solidified aluminum alloy powder was first used in the USA,/sup 1)/ commercialization for consumer market was first realized in Japan./sup 2)/ In order to achieve the viable cost-performance including Near Net Shape (NNS) formability, we developed three processes, powder extrusion, powder forging and sintering. The new powder extrusion process does not use either capsulation or vacuum degassing. The new powder forging does not need lateral flow. The new sintering process does not use liquid phase. The performance achieved by the processes is outstanding mechanical or physical properties that has potential to substitute cast iron, steel, titanium Metal Matrix Composite (MMC) or Ingot Metallurgy (IM) aluminum alloys. Cooperation with customers, powder suppliers and research associations contributed to the advancement of PM aluminum alloys in Japan.

• 청정기술
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• 제25권1호
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• pp.14-18
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• 2019

여러 금속 부품을 가공하기 위하여 사용된 염화제이철 에칭 폐액은 유가금속인 니켈 등을 함유하고 있다. 본 연구에서는 식각공정을 완료한 에칭폐액을 재생하고 부산물로 나온 니켈 함유 폐액으로부터 정제하여 니켈 금속분말로 제조하는 공정을 개발하였다. 부산물인 니켈함유용액을 철 등의 불순물을 침전 제거하기 위하여 수산화나트륨 수용액을 실험을 통하여 가수분해 중화제로서 선정하였고, 이를 통하여 철 등의 불순물을 pH = 4 조건하에 침전 제거하였다. 그 후, 불순물로 잔류하는 망간 및 아연과 같은 금속이온들을 D2EHPA (Di-(2-ethylhexyl) phosphoric acid)를 사용하여 용매추출 하였다. 정제된 염화니켈은 99% 이상의 순도를 가지고 있으며, 그 후 환원제로 하이드라진을 이용하여 99% 이상의 순도와 약 150 nm의 크기를 가지는 니켈 금속분말로 제조하였다. 염화니켈 및 니켈 금속분말의 성분은 EDTA 적정법과 유도결합 플라즈마 방출분광법(inductively coupled plasma optical emission spectrometer, ICP-OES)을 이용하여 확인하였으며, 전계방사 주사전자현미경(field emission scanning electron microscope, FE-SEM), X-선 회절분석기(X-ray diffraction, XRD) 및 투과전자현미경(transmission electron microscopy, TEM)을 통하여 금속분말의 형태, 입자 크기 및 결정성과 같은 물리적 특성을 확인하였다.

• Tribology and Lubricants
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• 제30권6호
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• pp.330-336
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• 2014

Sintered metallic brake pads and low alloy heat resistance steel disks are applied to mechanical brake systems in high energy moving machines that are associated with recently developed 200km/h trains. This has led to the speed-up of conventional urban rapid transit. In this study, we use a lab-scale dynamometer to investigate the effects of the composition of friction materials on the tribological characteristics of sintered metallic brake pads and low alloy heat resistance steel under dry sliding conditions. We conduct test under a continuous pressure of 5.5 MPa at various speeds. To determine the optimal composition of friction materials for 200 km/h train, we test and the evaluate frictional characteristics such as friction coefficients, friction stability, wear rate, and the temperature of friction material, which depend on the relative composition of the Cu-Sn and Fe components. The results clearly demonstrate that the average friction coefficient is lower for all speed conditions, when a large quantity of iron power is added. The specimen of 25 wt% iron powder that was added decreased the wear of the friction materials and the roughness of the disc surface. However when 35 wt% iron powder was added, the disc roughness and the wear rate of friction materials increased By increasing the amount of iron powder, the surface roughness, and temperature of the friction materials increased, so the average friction coefficients decreased. An oxidation layer of $Fe_2O_3$ was formed on both friction surfaces.

• 대한기계학회논문집A
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• 제22권2호
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• pp.330-342
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• 1998

The effect of rubber mold on densification behavior of pure iron powder was investigated under cold isostatic pressing. The thickness effect of rubber mold was also studied. The elastoplastic constitutive equation based on the yield function of Shima and Oyane was implemented into the finite element program(ABAQUS) to predict compaction responses of metal powder under cold isostatic pressing. The hyperelastic constitutive equation based on Moony-Rivlin and Ogden strain energy potentials was also employed to analyze deformation of rubber mold. The coefficients of the strain energy potentials were obtained from tension and volumetric compression data of rubber. Finite element results were compared with experimental data for densification of pure iron powder under cold isostatic pressing.

• 한국분말재료학회지
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• 제23권4호
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• pp.276-281
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• 2016

Carbonyl iron (CI) is successfully incorporated as an additive into a polystyrene (PS) matrix via a highenergy ball milling method, under an n-hexane medium with volume fractions between 1% and 5% for electromagnetic interference shielding applications by the combination of magnetic CI and an insulating PS matrix. The morphology and the dispersion of CI are investigated by field emission scanning electron microscopy, which indicates a uniform distribution of CI in the PS matrix after 2 h of milling. The thermal behavior results indicate no significant degradation of the PS when there is a slight increase in the onset temperature with the addition of CI powder, when compared to the as-received PS pellet. After milling, there are no interactions between the CI and the PS matrix, as confirmed by Fourier transformed infrared spectroscopy. In this study, the milled CI-PS powder is extruded to make filaments, and can have potential applications in the 3-D printing industry.

• 한국자원리싸이클링학회:학술대회논문집
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• 한국자원리싸이클링학회 1993년도 EARTH 발표논문초록
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• pp.3.1-3
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• 1993