• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 춘계학술발표강연 및 논문개요집
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• pp.221-221
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• 2003

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 1997년도 특별강연 및 추계학술발표 개요집
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• pp.125-127
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• 1997

• 한국재료학회:학술대회논문집
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• 한국재료학회 2002년도 춘계 학술발표강연 및 논문개요집
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• pp.79-79
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• 2002

• 한국자기학회지
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• 제8권6호
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• pp.362-368
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• 1998

반강자성 Cr86Al14계 스핀밸브막의 자기특성과 내열 내식성에 대해 연구하엿다. Cr86Al14스핀밸브막의 자기적성질은 강자성층, 자성층 및 비자성층두께에 의존하였으며, glass/Cr86Al14(600$\AA$)/Ni81Fe19(50$\AA$)/Cu(40$\AA$)/Ni81Fe19(40$\AA$)구조에서의 교환결합자장(Hex)은 20 Oe, 자기저항비(MR ratio (%))는 2%를 나타내었다. Cr96Al14 및 Fe50Mn50 스핀밸브막은 annealing온도가 증가함에 따라 모두 Hex 및 MR비가 감소하는 경향을 나타내엇으나 FeMn막에 비해 CrAl막이 우수하여, FeMn막은 15$0^{\circ}C$, CrAl막은 25$0^{\circ}C$에서 Hex 및 MR비값을 상실하였다. 또한 가혹한 환경에서의 스핀밸브막의 부식저항성을 평가하고자 35$^{\circ}C$,90% 습도상태의 챔버내에서 Hex와 MR비값의 변화를 관찰한 결과 CrAl막의 경우에는 Hex 및 MR비 값이 시간이 경과해는 변화지 않았으나, FeMn막은 15일정도 경과하자 거의 상실하는 결과를 나타냈다. SEM관찰결과 FeMn막은 pitting이 나타났으며 15일정도 경과후에는 박리가 발생하였다.

• 한국분말재료학회지
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• 제18권2호
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• pp.122-128
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• 2011

This study investigated the high temperature oxidation behavior of Ni-22.4%Fe-22%Cr-6%Al (wt.%) porous metal. Two types of open porous metals with different pore sizes of 30 PPI and 40 PPI (pore per inch) were used. A 24-hour TGA test was conducted at three different temperatures of $900^{\circ}C$, $1000^{\circ}C$ and $1100^{\circ}C$. The results of the BET analysis revealed that the specific surface area increased as the pore size decreased from 30 PPI to 40 PPI. The oxidation resistance of porous metal decreased with decreasing pore size. As the temperature increased, the oxidation weight gain of the porous metal also increased. Porous metals mainly created oxides such as $Al_2O_3$, $Cr_2O_3$, $NiAl_2O_4$, and $NiCr_2O_4$. In the 40 PPI porous metal with small pore size and larger specific surface area, the depletion of stabilizing elements such as Al and Cr occurred more quickly during oxidation compared to the 30 PPI porous metal. Ni-Fe-Cr-Al porous metal's high-temperature oxidation micro-mechanism was also discussed.

• 에너지공학
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• 제8권2호
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• pp.256-264
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• 1999

본 연구에서는 메탄의 부분산화반응에 미치는 base metal 의 영향을 살펴보기 위하여 6~l2wt%의 Mn, Cu, V, Co, Cr 그리고 Ba 등이 2 wt% Pt, 70 wt% Alumina, 28 wt% Ceria and Zirconia 와 함께 cordierite (2MgO.2Al$_2$O$_3$.5SiO$_2$)에 담지된 Pt-B/cordierite 촉매(B: base metal)를 사용하여 메탄의 부분산화반응 실험을 수행하였다. 메탄의 부분산화반응에 대한 활성은 Ba, Co그리고 Cr 담지 촉매는 Ni담지 촉매와 유사하게 Mn, Cu, V을 담지 했을 때 보다 우수한 것으로 나타났으나, 코크 생성에 대한 활성도 큰 것으로 나타났다. 또한 5wt% Ni/Al$_2$O$_3$촉매를 이용한 메탄의 부분산화반응 실험 후의 촉매에 대한 XRD 분석결과 Ni은 3가지 형태의 상으로 존재하는 것을 확인할 수 있었으며, 촉매층 전단에서는 주로 NiAl$_2$O$_4$와 NiO 형태로 존재하여 메탄의 산화반응이 일어나며, 그리고 촉매층 후단에서는 환원상태의 Ni로 존재는 것으로 보아 개질반응이 일어나는 것을 알 수 있었다.

• 소성∙가공
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• 제7권5호
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• pp.465-473
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• 1998

The effect of alloying elements of Ag-Cu-Zr-X brazing alloy on the microstructure and the bond strength of $Al_2O_3/Ni-Cr$ brazed steel joint was investigated. The reaction layer, $ZrO_2$ (a=5.146 ${\AA}$ , b=5.213 ${\AA}$ , c=5.311 ${\AA}$ )was formed at the interface of $Al_2O_3/Ni-Cr$ steel joint by the redox reaction between alumina and Zr. The addition of An and Al to the Ag-Cu-Zr brazing alloy gave rise to changes in the thickness of the reaction product layer and the morphology of the brazement. Sn caused the segregation of Zr was decreased b Al the $ZrO_2$ layer formed at the Ag-Cu-Zr-Al alloy was thinner than that of $ZrO_2$ formed at the Ag-Cu-Zr-An alloy. The fracture shear strength was strongly dependent on the microstructure of the brazement. Brazing with Ag-Cu-Zr-Sn alloy resulted in a better bond strength than with Ag-Cu-Zr or Ag-Cu-Zr-Al alloy.

• 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.

• 한국표면공학회지
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• 제34권5호
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• pp.499-502
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• 2001

Functionally gradient NiCrAlY/$ZrO_2$-$Y_2$$O_3$ and NiCrAlY/$ZrO_2$- $CeO_2$-$Y_2$$O_3$ coatings were prepared by APS. The as-sprayed microstructure consisted of metal-rich and ceramic-rich regions, between which $Al_2$$O_3$-rich layers existed owing to the oxidation during APS. During oxidation between 900 and $1100^{\circ}C$ in air, the pre-existing $Al_2$$O_3$-rich scales grew, due mainly to the preferential reaction of Al with inwardly transporting oxygen along the heterogeneous phase boundaries. As the amount of ceramics in the coating increased, the oxidation resistance increased.

• 한국표면공학회지
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• 제30권4호
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• pp.248-254
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• 1997

The sulfidation behavior of a sputter-deposited amorphous coating of 69.0%Nb-16.9Ni-11.9%Al-2.2%Si (at.%) has been investigated as a funtion of temperature.(973-1173K) in pure sulfur pressure of 0.01atm. The sulfidation kinetics of the casting obyed the parabolic rate low over the whole temperature ranges studied. The stlfidation rate increased with the temperature, as expected. The sulfide scale, the composition of which was $Al_2S_3,\;NbS_2,\;Ni_{3-x}S_2\;and\;FeCrS_4$, formed on the amorphous coating was primarily bilayered. Both the outer fastgrowing non-protective 4Al_2S_3$scale and the inner slowly-growing protective $NbS_2$,/TEX> scale and the inner slowly-growing protective $NbS_2$ scale had some Fe and Cr dissolution, which evidently came from the base substrate alloy of stainless steel type 304. Belows the coating, Kirkendall void formation was noticed. Nevertheless, a dramatic improvement of sulfidation resistance was achieved by sputter-depositing Nb-2 Ni-Al-Si layer on the stainless steel 304.