• 한국재료학회:학술대회논문집
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• 한국재료학회 2007년도 추계학술발표대회 및
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• pp.123.1-123.1
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• 2007

• 한국재료학회:학술대회논문집
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• 한국재료학회 2007년도 추계학술발표대회 및
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• pp.121.1-121.1
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• 2007

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2005년도 춘계학술발표회
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• pp.289-290
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• 2005

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2005년도 추계학술발표회
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• pp.219-220
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• 2005

• 한국재료학회:학술대회논문집
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• 한국재료학회 2005년도 춘계학술발표대회 및 제8회 신소재 심포지엄 논문개요집
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• pp.83-83
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• 2005

• 한국재료학회지
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• 제25권12호
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• pp.694-702
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• 2015

Nd-Fe-B permanent magnets have been used in a wide variety of applications because of their high magnetic flux density. So, demand for neodymium has been increasing in worldwide. In this study, an electrowinning process was performed in $LiF-NdF_3-Nd_2O_3$ high temperature molten salts. However, a corrosion resistant material for use in the molten salt must be found for stable operation because of the harsh corrosion environment of the electrowinning process. Therefore, for this paper, boron nitride(BN), aluminum nitride(AlN), and silicon nitride($Si_3N_4$) were selected as protective and structural materials in the high temperature electrolyte. To investigate the characteristics of BN, AlN, and $Si_3N_4$, in molten salts, materials were immersed in the molten salts for 24, 72, 120, and 192 hours. Also, surface condition and stability were investigated by SEM and EDS and corrosion products were calculated by HSC chemistry. As a result, among BN, AlN, and $Si_3N_4$, AlN was found to show the best protective material properties.

• Journal of Ceramic Processing Research
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• 제13권spc2호
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• pp.308-311
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• 2012

A wide range of possible hazards existing in thermal batteries are mainly caused by thermal runaway, which results in overheating or explosion in extreme case. Battery separators ensure the separation between two electrodes and the retention of ion-conductive electrolytes. Thermal runaways in thermal batteries can be significantly reduced by the adoption of these separators. The high operating temperature and the violent reactivity in thermal batteries, however, have limited the introduction of conventional separators. As a substitute for separators, MgO powders have been mostly used as a binder to hold molten salt electrolyte. During recent decades the fabrication technology of ceramic fiber, which has excellent mechanical strength and chemical stability, has undergone significant improvement. In this study we adopted wet-laid nonwoven paper making method instead of the electrospinning method which is costly and troublesome to produce in volume. Polymeric precursor can readily be coated on the surface of wet-laid ceramic paper, and be formed into ceramic film after heat treatment. The mechanical strength and the thermo-chemical stability as well as the wetting behaviors of ceramic separators with various molten salts were investigated to be applicable to thermal batteries. Due to their excellent chemical, mechanical, and electrical properties, wet-laid nonwoven separators made from ceramic fibers have revealed positive possibility as new separators for thermal batteries which operate at high temperature with no conspicuous sign of a short circuit and corrosion.

• Advances in materials Research
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• 제1권3호
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• pp.233-243
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• 2012

Thermal reactive diffusion coating of vanadium carbide on DIN 2714 steel substrate was performed in a molten borax bath at $950-1050^{\circ}C$. The coating formed on the surface of the substrate had uniform thickness ($1-12{\mu}m$) all over the surface and the coating layer was hard (2430-2700 HV), dense, smooth and compact. The influence of the kinetics parameters, temperature and time, has been investigated. Vanadium carbide coating was characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX) and X-ray diffraction analysis (XRD). The corrosion resistance of the coating was evaluated by potentiodynamic polarization in 3.5% NaCl solution. The results obtained showed that decrease of coating microhardness following increasing time and temperature is owing to the coarsening of carbides and coating grain size.

• 방사성폐기물학회지
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• 제8권1호
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• pp.33-39
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• 2010

산화물 사용 후 핵연료를 처리하는 전해환원공정에서는 LiCl 용융염계에서 산소가 생성되는 반응을 수반하게 되며, 생성된 산소로 인해 반응기의 구조재료를 상당히 부식시킬 수 있는, 화학적으로 심각한 반응환경을 조성한다. 따라서, 고온 용융염을 다루는 전해환원 공정장치를 위해서는 최적의 재료를 선택하는 것이 필수적이다. 본 연구에 서는 리튬용융염, $675^{\circ}C$, 216시간동안 산화분위기에서 코팅이 안 된 초합금과 코팅된 초합금 시편의 고온 부식연구를 수행하였다. IN713LC 초합금 시편에 aluminized NiCrAlY bond 코팅 후 $Y_2O_3$ top 코팅을 하였다. 코팅이 안 된 초합금은 부식층의 빠른 성장응력과 열적응력에 의한 부식층의 박리로 명확한 무게손실을 보인다. 탑 코팅의 화학적 및 열적 안정성으로 인해 고온 리튬용융염을 다루는 구조재료의 부식 저항성이 증가함을 확인할 수 있었다.

• 한국표면공학회지
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• 제32권3호
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• pp.341-343
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• 1999

The morphology and composition of anodic films, formed on aluminium at various current densities, in the range $1-100{\;}Am^{-2}$, in the molten bisulphate melt at different temperatures (418-498K), have been studied using transmission electron microscopy of ultramicrotomed film sections, and ion beam thinned films. The first sign of incipient breakdown revealed by transmission electron microscopy of stripped films, is always the appearance of dark regions about 1,000 nm in diameter, representing local overgrowth of the film. The breakdown mechanism is closely related to thermal effects, because temperature rises at regions representing local overgrowth in the stripped films were observed at voltages close to the breakdown voltage, likely arising through impact ionization.