• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 추계학술대회 논문집
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• pp.208-208
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• 2009

메탄의 수증기-이산화탄소 복합개질반응에서 니켈 촉매의 탄소 침적 저항성에대한 Ce 증진 효과를 살펴보기 위해, Ni-Ce/${\alpha}-Al_2O_3$ 촉매를 제조하였다. Ce/Ni 비율 변화에 따른 촉매 비표면적, Ni 입자 분산도 및 촉매 활성 변화를 살펴보았고, Ce 첨가량을 최적화 할 수 있었다. Ce/Ni 비율 증가에 따라 NiO 결정크기가 감소하고 표면적과 Ni 분산도는 증가하였다. 특히, Ce/Ni=0.5 첨가 시, 촉매는 가장 넓은 비표면적과 Ni 분산도를 가졌으며, 우수한 촉매 활성 및 높은 탄소 침적 저항성을 보였다. 또한, 본 연구에서는 Ni과 Ce 담지 방법에 따른 Ni 분산도 향상과 Ni과 Ce간의 접촉 면적 극대화를 통한 활성산소 공급 향상에 대한 영향을 함께 살펴보았다. Ni과 Ce를 동시 함침법과 연속 함침법으로 담지하여 비교한 결과, 동시 함침법으로 제조한 Ni-Ce/${\alpha}-Al_2O_3$ (Ce/Ni=0.5) 촉매가 가장 우수한 촉매 성능 및 높은 탄소 침적 저항성을 보였다. 이는 동시 함침법으로 고분산된 Ni 입자와 담체간의 강한 상호작용 형성과 원활한 활성 산소 공급에 기인한 것이다.

• 한국세라믹학회지
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• 제15권2호
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• pp.66-71
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• 1978

The cobalt blue spinel stains (main composition; CoO:$Al_2O_3$=1 : 1) in CoO-NiO-$Al_2O_$3 and $CoO-Al_2O_3-Cr_2O_3$ system were prepared by the calcination of each component oxides to be adequate for the factory. The color development, the change of the lattice constnat of the spinel and its application to colored glazes were studied. The results were summarized as follows. 1) In CoO-Al_2O_3$ spinel, the excess addition of each component hardly made any variation in lattice constantand alumina-rich spinel specimens caused the brilliant blue color fade. 2) An increase of $Ni^{2+}$ in $CoO-NiO-Al_2O_3$ system, made the lattice constnat of the $CoO-Al_2O_3$ spinel smaller, and an increase of $Cr^{3+}$ in $CoO-Al_2O_3-Cr_2O_3$, larger. 3) Glazed stains under lead glaze were colored nearly same dark blue color fade.

• 청정기술
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• 제13권4호
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• pp.287-292
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• 2007

상용 알루미나($Al_2O_3$)에 담지된 $M/Al_2O_3$ (M = Mn, Fe, Co, Ni, Cu) 촉매를 함침법에 의해 제조하였으며, 이를 에탄을 자열개질반응에 의한 수소제조에 적용하였다. 각각의 촉매는 고유한 금속상을 가지는 것으로 나타났으며, 생성물의 분포는 활성금속의 종류에 크게 의존하였다. 제조된 촉매 중에서, $M/Al_2O_3$ 및 Co/$Co/Al_2O_3$는 에탄을 자열개질반응에서 매우 우수한 촉매활성을 보였다. 그러나 두 촉매상에서의 반응메커니즘은 서로 다른 것으로 나타났다. $Ni/Al_2O_3$ 촉매는 $500^{\circ}C$의 반응온도에서 100%의 에탄올 전환율을 보였으나, 수소 선택도에서는 시간에 따라 급격한 저하현상을 나타내었다. 한편 $Co/Al_2O_3$ 촉매는 수소 선택도 면에서 우수한 활성을 보였으나, 에탄올 전환율이 저조하여 수소 수율에는 큰 변화가 나타나지 않았다.

• 열처리공학회지
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• 제8권3호
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• pp.236-243
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• 1995

Since amorphous alloys have been known to have better mechanical and chemical properties than crystalline alloys of the same composition, a great number of studies on the formation of Al-based amorphous alloys have been carried out actively. However, little has been obtained about the effect of Rare-Earth metal and Transition metal addition on amorphous phase formed by melt spinning method. This study included fabrication of amorphous alloy $Al_{85}Ce_5Ni_{10}$ by melt spinning methods and DTA, XRD, TEM analysis to determine crystalization behavoir. Annealing treatments were carried out in Ar atmosphere under isothermal and nonisothermal conditions. The diffraction pattern of non-heated ribbons showed broad form characteristic of glass metallic alloy. The crystallization of amorphous $Al_{85}Ce_5Ni_{10}$ takes place eutedtoidly by homogeneous formation of Al and MS-1, followed by precipitation of the $Al_{11}Ce_3$ and later $MS-1{\rightarrow}Al_3Ni$ transformation.

• 한국재료학회지
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• 제15권8호
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• pp.503-507
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• 2005

Microstructure and wear behavior of A1203-based nanocomposites with Cu and Ni-Co dispersions were investigated. $Al_2O_3/Cu$ and $Al_2O_3/Ni-Co$ nanocomposites were fabricated by hydrogen reduction and sintering method using metal oxide and metal nitrates. The nanocomposites showed increased mechanical properties compared with monolithic $Al_2O_3$. In particular, high toughness and hardness were measured for the $Al_2O_3/Ni-Co$ nanocomposite consolidated by spark plasma sintering. A minimum value of wear coefficient comparable to the monolithic $Al_2O_3$ was obtained for $Al_2O_3/Ni-Co$ nanocomposite. Wear behavior is discussed in terms of microstructure and mechanical properties of nanocomposites

• 전기화학회지
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• 제19권3호
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• pp.57-62
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• 2016

The over-discharging phenomena in sodium-nickel chloride batteries were investigated in relation to decomposition of molten salt electrolyte and consequent metal co-deposition. From XRD analysis, the material deposited on graphite cathode current collector was revealed to be by-product of molten salt electrolyte decomposition. In particular, the result showed that the Ni-Al alloys ($Al_3Ni_2$, $Ni_3Al$ and $Al_3Ni$) were electrochemically deposited on graphite current collectors in line with over-discharging behaviors. It is assumed that the $NiCl_2$ solubility in molten salt electrolytes leads to the co-deposition of Ni-Al alloys by increasing metal deposition potential above 1.6 V (vs. $Na/Na^+$). The cell tests have revealed that the composition of molten salt electrolytes modified by various additives makes a decisive influence on the over-discharging behaviors of the cells. It was revealed that NaOCN addition to molten salt electrolytes was advantageous to suppress over-discharge reactions by modifying the characteristics of molten salt electrolytes. NaOCN addition into molten salt electrolytes seems to suppress Ni solubility by maintaining basic melts. The cell using modified molten salt electrolyte with NaOCN (Cell D) showed relatively less cell degradation compared with other cells for long cycles.

• 한국주조공학회지
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• 제7권4호
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• pp.352-357
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• 1987

Recently there were many studies on the development of cast iron for increasing strength, thermal resistance and mechanical properties, etc. The effects on mechanical properties and variation of solidification structure of hypo-eutectic cast iron was investigated when Ni(Al) was added with a fixed quantity of Al(Ni) content. The conclusions are as follows. 1) Tensile strength was the maximum(over 41 kg/ $mm^2$) when Al is added about 0.72%. 2) Torsional strength and angle were increased with increasing Al content and represents maximum value, when Al and Ni content are 1.5 and 2.0%. 3) With increasing Ni content, tensile strength decreased because of the effect of graphite coarsening. But torsional strengths were increased with the appropriate addition of (Ni%+Al%) content because of the effect of strengthened matrix.

• 대한기계학회논문집A
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• 제23권7호
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• pp.1245-1252
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• 1999

The sliding wear behavior of $Al_2O_3/NiCr$ coating deposited on steel(SM45C) was investigated under lubrication. The parameters of sliding wear are normal loads, coating thickness. As a result, the wear resistance of $Al_2O_3/NiCr$ coating was remarkably greater than that of $Al_2O_3$ coating. The optimized coating thickness was found to be $300{\mu}m$ to ensure good anti-wear. The bond coating played important role in decreasing residual stress. The residual stress had much influence on wear mechanism. These results were correlated with the stress state of coating and the microstructure of coating.

• 한국표면공학회지
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• 제44권5호
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• pp.196-200
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• 2011

The Ni-based superalloy, Inconel 713, was oxidized at $800{\sim}1100^{\circ}C$ for 50 and 100 hours in air. It displayed excellent oxidation resistance, forming a few micrometer-thick scales. The major scale was ${\alpha}-Al_2O_3$. Other scales formed were $TiO_2$, $NiAl_2O_4$ and $Cr_2O_3$. Generally, uniform oxidation occurred over the alloy surface, resulting in the formation of ${\alpha}-Al_2O_3$ with and without $Cr_2O_3$. Other oxides such as $TiO_2$ and $NiAl_2O_4$ sometimes also formed. Locally, nodular oxidation occurred at the nodules that consisted of diverse alloying elements. The scales were adherent at $800^{\circ}C$. However, they spalled a little at $900{\sim}1100^{\circ}C$.

• 한국재료학회지
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• 제31권12호
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• pp.672-676
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• 2021

In this paper, the effect of Ni (0, 0.5 and 1.0 wt%) additions on the microstructure, mechanical properties and electrical conductivity of cast and extruded Al-MM-Sb alloy is studied using field emission scanning electron microscopy, and a universal tensile testing machine. Molten aluminum alloy is maintained at 750 ℃ and then poured into a mold at 200 ℃. Aluminum alloys are hot-extruded into a rod that is 12 mm in diameter with a reduction ratio of 39:1 at 550 ℃. The addition of Ni results in the formation of Al₁₁RE₃, AlSb and Al3Ni intermetallic compounds; the area fraction of these intermetallic compounds increases with increasing Ni contents. As the amount of Ni increases, the average grain sizes of the extruded Al alloy decrease to 1359, 536, and 153 ㎛, and the high-angle grain boundary fractions increase to 8, 20, and 34 %. As the Ni content increases from 0 to 1.0 wt%, the electrical conductivity is not significantly different, with values from 57.4 to 57.1 % IACS.