• 한국자기학회:학술대회 개요집
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• 한국자기학회 2000년도 International Symposium on Magnetics The 2000 Fall Conference
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• pp.506-507
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• 2000

• 한국재료학회:학술대회논문집
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• 한국재료학회 1998년도 IUMRS-ICEM ABSTRACT BOOK
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• pp.143.3-143
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• 1998

• 한국재료학회:학술대회논문집
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• 한국재료학회 1996년도 재료학회 추계학술발표회
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• pp.3-4
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• 1996

• 한국분말재료학회지
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• 제1권1호
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• pp.66-71
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• 1994

Optical microstructures and mechanical properties of Na gas atomized Al-20Si-5Fe alloying powder and its hot extrudates were studied on 3 different types of powder size distribution. This powder showed the size distribution of 10~210 $\mu\textrm{m}$. Also the microstructures of $\alpha$-Al, primary and eutectic Si and needle shaped intermetallic compounds were observed by optical microscope. These needle shaped intermetallic compounds were identified as ${\delta}Al_4FeSi_2$- by XRD and EDX analysis. The ultimate tensile strength(UTS) of these alloy extrudates was increased from 324 to 390 MPa with decreasing powder size range from 120~210 $\mu\textrm{m}$ to 10~64 $\mu\textrm{m}$. A value of Micro-vic-kers hardness was simillar to the result of UTS. These extrudates showed better wear resistance than those of Al-20Si-2X(X : Ni, Cr, Zr), although they are insensitive to the size distribution. These results indicate that the presentation of ${\delta}Al_4FeSi_2$ intermetallic compounds contributed to the wear resistance improvement.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.1164-1167
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• 2003

Recently CRT is getting flatted, As change of CRT trend from normal type to Flat type, the material of Shadow Mask was also changed from AK(Aluminum Killed) to Invar(Fe-Ni alloy) materials Until now we have used just AK(Aluminum Killed) for normal type TV(not flat type), but main raw material of shadow mask component was changed. . However recently Invar(Fe-Ni alloy) materials, which has advantage of Low Thermal Expansion and High Strength, has been developed as well as applying in mass production as CRT's trend has become more flat and fine pitch. As main raw material of shadow mask component was changed, conditions of process were changed. One of them, the importance of pre-etching process (assistant process for developing & etching) is improved because there are so many particles in the pre-etching bath because of Ni compounds. Since the solubility of Ni in pre-etching solvent is very low related to Fe's, so the compounds of Ni happen to make particles.(the solubility of Fe is twenty times Ni's) that particles happen to make process troubles and NG productions so to clear the particles we had to established high cost filtering system, but it is useless. As time goes by the quantity of particles (Ni compounds) was increased because of the capability of filtering system was not enough, the particles was produced continuous in bath, and it make quality problems. Hence we tried to develop the new pre-etching solution to remove the particles (Ni compounds) and to cost down the filtering system's running cost. But in improving the solution we discovered the new pre-etching solution made the PR developing better. In former solution there were three kinds of chemistry (COOH)2 , H2O2 , H2S04 .first the function of (COOH)2 is drilling the surface of Invar, during this mechanism Ni compounds occurred. Second the function of H202 is removing the PR fringe (half UV exposure zone on PR(PVA)), Third the function of H2S04 is the catalysis of (COOH)2 In those, (COOH)2 was the main reason to make the Ni compounds. So to improve the solutions we had to change (COOH)2 to the other material. the chemistry we improved was a complex chemistry based on H2S04 . after using this chemistry the particles problem was disappeared and there was another advantage cut down the PR fringe. The New solution made the function of H202 better so the PR developing improved. To be direct the catalyst of the new solution helped the H202. anyway First thing after change the solution the quality of shadow Mask for flat color TV was improved & the yield also improved. But the more important thing is how to control the new solution. So we accepted the new concept which was the degree of freshness. The degree of freshness is based on non-reacted solution which was 100% ( the degree of freshness) and calculated the melted Ni quantity as time goes by. So we made the gauging liner plot. In conclusion, many companies tried to make fine pitched Shadow Mask ,generally to make quality jump up it needed a lot of cost & persons .in this case the shift of core material made it possible.

• 한국분말재료학회지
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• 제2권1호
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• pp.53-62
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• 1995

TLP(Transient-Liquid-Phase) bonding of Fe-base MA956 ODS alloy was performed. As insert metal a commercially available Ni-base alloy(MBF50) and an MA956 alloy with additive elements of 7wt% Si and 1wt% B were used. To confirm the idea that a concurrent use of MA956 powder with Insert metals can enhance the homogenization of constituent elements and thereby reduce the thickness of joint interface, MA956 powder was also inserted In a form of sheet. SEM observation and EDS analysis revealed that Cr-rich phase was formed in the bonded interface in initial stage of isothermal solidification during the bonding process, irrespective of kind of insert metals. Measurement of hardeness in the region of bonded interface and EDS analysis showed that a complete homogenization of composition could not be obtained especially in case of MBF50. Joints using either BSi insert metals only or BSi insert together with MA956 powder interlayer showed, however, a remarkable improvement in a compositional homogenization, even though a rapid grain growth in the bonded interface could not be hindered.

• 한국전기전자재료학회논문지
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• 제14권1호
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• pp.74-83
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• 2001

In this study, the optimum structure of a magnetic thin film inductor was designed for application of DC-DC converters. The Ni$\sub$81/Fe$\sub$19/ (at%) alloy was selected as a high-frequency($\geq$MHz) magnetic thin film magnetron sputtering system. As-deposited NiFe thin films show similar magnetic properties compared to bulk NiFe alloys, indicating that they have a good film quality. The optimum design of dolenoid-type magnetic thin film inductors was performed utilizing a Maxwell computer simulator (Ansoftt HFSS V7.0 for PC) and parameters obtained from the magnetic properties of magnetic core materials selected. The high-frequency characteristics of the inductance(L) and quality factor(Q) obtained for the designed inductors through simulation agreed well with those obtained by theoretical calculations, confirming that the simulated result is realistic. The optimum structure of high-performance (Q$\geq$60, L = 1${\mu}$H, efficiency $\geq$90%), high-frequency ($\geq$5MHz), and solenoid-type magnetic thin film inductors was designed successfully.

• 한국재료학회지
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• 제14권4호
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• pp.251-259
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• 2004

In the development of the advanced spent fuel management process based on the molten salt technology, it is essential to choose the optimum material for the process equipment handling molten salt. Corrosion behavior of Ni 200 and Ni-base alloys in molten salt of LiCl-$Li_2$O under oxidation atmosphere was investigated in the temperature range of $650～800^{\circ}C$ for 24～312 hrs. The order of corrosion rate was Ni 200 > Inconel 690 > Inconel 601 > Inconel 600. Inconel 600 alloy showed the highest corrosion resistance among the examined alloys, but Ni 200 exhibited the highest corrosion rate. Corrosion products of Inconel 600 and Inconel 601 were $Cr_2$$O_3$ and $NiFe_2$$O_4$. In case of Inconel 690, a single layer of $CrO_2$$O_3$ was formed in the early stage of corrosion and an outer layer of $NiFe_2$O$_4$ and inner layer of $Cr_2$$O_3$ were formed with increase of corrosion time. Inconel 600 showed local corrosion behavior and Inconel 601, 690 showed uniform corrosion behavior.

• 한국재료학회지
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• 제25권1호
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• pp.43-47
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• 2015

$Zn(BH_4)_2$ was prepared by milling $ZnCl_2$ and $NaBH_4$ in a planetary ball mill in an Ar atmosphere, and XRD analysis, SEM observation, FT-IR analysis, DTA, and TGA were performed for synthesized $Zn(BH_4)_2$ samples. 90 wt% $MgH_2$+1.67 wt% $Zn(BH_4)_2(+NaCl)$+5 wt% Ni+1.67 wt% Ti+1.67 wt% Fe (named $90MgH_2+1.67Zn(BH_4)_2(+NaCl)$+5Ni+1.67Ti+1.67Fe) samples were also prepared by milling in a planetary ball mill in an $H_2$ atmosphere. The gas absorption and release properties of the $Zn(BH_4)_2(+NaCl)$ and $90MgH_2+1.67Zn(BH_4)_2(+NaCl)_2(+NaCl)$+5Ni+1.67Ti+1.67Fe samples were investigated. An FT-IR analysis showed that $Zn(BH_4)_2$ formed in the $Zn(BH_4)_2(+NaCl)$ samples prepared by milling $ZnCl_2$ and $NaBH_4$. At the first cycle at $320^{\circ}C$, $90MgH_2+1.67Zn(BH_4)_2(+NaCl)$+5Ni+1.67Ti+1.67Fe absorbed 2.95 wt% H for 2.5 min and 4.93 wt% H for 60 min under 12 bar $H_2$, and released 1.46 wt% H for 10 min and 4.57 wt% H for 60 min under 1.0 bar $H_2$.

• 자원리싸이클링
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• 제17권1호
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• pp.51-58
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• 2008

Cu-Ni-Co-Fe 함금상에 황의 원료로서 pyrite 또는 chalcopyrite를 첨가하여 매트상을 제조하는 방법에 대하여 검토하였다. 두 매트상 모두 주성분은 $(FeSi)_9S_8$, $CuFeS_2$, FeS, $Co_4S_3$, $Ni_3S_2$ 그리고 $Cu_2S$의 금속황화물 이었으며, chalcopyrite를 첨가한 매트의 경우 구리의 함량이 높아 $Cu_2S$의 피크가 더 높게 나타났다. 제조한 매트상의 침출 결과 모두 구리는 95%이상, 니켈과 코발트는 90% 이상의 침출율을 보였다. Pyrite와 chalcopyrite 첨가량이 증가할수록 침출액의 pH는 낮아지고, 용해되어 있는 철이온의 농도와 잔사량은 증가하였다. 한편 매트 중 황의 함량변화에 따른 유가금속의 침출율은 모든 시료에 대해 크게 변하지 않았으며, 다만 pyrite를 이용하여 제조한 매트의 경우에 Ni과 Co가 황 함량 증가에 따라 다소 증가하는 경향을 나타내었다.