• Journal of Welding and Joining
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• v.31 no.5
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• pp.64-70
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• 2013

The joining of Ti and SUS304 dissimilar metals is one of the effective measures to save rare metal. But Ti and SUS304 have differences in materials properties, and Ti and Fe intermetallic compounds such as TiFe and $TiFe_2$ are easily formed in weld fusion zone between Ti and SUS304. Nevertheless, in this study, full penetration lap dissimilar welding of Ti and SUS304 using single-mode fiber laser with ultra-high welding speed was tried, and it was found out that ultra-high welding speed could control the generation of intermetallic compound. To recognize the formation of intermetallic phase in the weld fusion zone and the compound zone of interface weld area were observed and analyzed using energy dispersive X-ray spectroscopy (EDX). And it was confirmed that the ultra-high welding speed could reduce amount of intermetallic compounds, but the intermetallic compounds were existed in the weld fusion zone under the all conditions.

• Bulletin of the Korean Chemical Society
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• v.23 no.7
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• pp.948-952
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• 2002

Three-dimensional terbium coordination polymers with the formulas of [Tb4(NDC)6(H2O)5]${\cdot}$2H2O (1) and [Tb2(BPDC)3(H2O)3]${\cdot}$H2O (2) (NDC = 2,6-naphthalenedicarboxylate; BPDC = 2,2'-bipyridine-4,4'-dicarboxy-late) were prepared by hydrothermal reactions. Both compounds were structurally characterized by X-ray diffraction. Compound 1 has a polymeric structure that contains four distinct Tb metals. Three Tb metals have a square-antiprismatic structure, and the remaining one has a 9-coordinate, triply capped trigonal-prismatic structure. Compound 2 is also a polymer with two distinct Tb metals, both of which have a square-antiprismatic structure. The pyridine nitrogen atoms of the BPDC 2- ligand do not coordinate to the metal centers in compound 2.

• Corrosion Science and Technology
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• v.7 no.4
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• pp.212-218
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• 2008

Inorganic ion exchange compounds (IECs) including hydrotalcites and bentonite clays are a well known classes of layered mixed metal hydroxides or silicates that demonstrate ion exchange properties. These compounds have a range of applications from water purification to catalyst supports. The use of synthetic versions of these compounds as environmentally friendly additives to paints for storage and release of inhibitors is a new and emerging application. In this paper, the general concept of storage and release of inhibiting ions from IEC-based particulate pigments added to organic coatings is presented. The unique aspects of the IEC structure and the ion exchange phenomenon that form the basis of the storage and release characteristic are illustrated in two examples comprising an anion exchanging hydrotalcite compound and a cation exchanging bentonite compound. Examples of the levels of corrosion protection imparted by use of these types of pigments in organic coatings applied to aluminum alloy substrates is shown. How corrosion inhibition translates to corrosion protection during accelerated exposure testing by organic coatings containing these compounds is also presented.

• Journal of the Korean Chemical Society
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• v.56 no.1
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• pp.54-57
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• 2012

New Schiff base derivatives of organoheterobimetallic-${\mu}$-oxoisopropoxide $[Bu_2SnO_2Ti_2(OPr^i)_6]$ have been synthesized by the thermal condensation ${\mu}$-oxoisopropoxide compound with Schiff bases in different molar ratios (1:1-1:4) yielded the compounds of the type $[Bu_2SnO_2Ti_2(OPr^i)_{6-n}(SB)_n]$ (where n is 1-4 and SB=Schiff base anion) respectively. The ${\mu}$-oxoisopropoxide derivatives have been characterized by elemental, spectral analysis (IR, $^1H$, $^{13}C$, $^{119}Sn$ NMR) and molecular weight measurement The studies reveal that the derivative compounds show monomeric nature. Further these are found less susceptible to hydrolysis as compared to parent compound and may prove excellent precursors for the mixed metal oxides.

• Bulletin of the Korean Chemical Society
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• v.27 no.10
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• pp.1553-1556
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• 2006

A diazatetrathia crown ether derivative that has two appended nitrobenzoxadiazolyl moieties showed selective OFF-ON type fluoroionophoric signaling properties toward Hg2+ ions over other transition metal ions. The compound also exhibited a pronounced chromogenic behavior toward Hg2+ ions by changing the solution color from light orange to yellow, which can easily be detected with naked-eye. The detection limit for the analysis of Hg2+ ions in 90% aqueous acetonitrile was found to be 4.8??10-6 M, which suggests that the compound may be used as a chemosensor for analyzing sub-millimolar Hg2+ ions in aqueous environments.

• Journal of the Korea Institute of Building Construction
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• v.1 no.1
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• pp.135-142
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• 2001

This study is for the investigation of form using the aluminum-compound metal frame(Aluminum frame reinforced panel : AFR panel) which is improved in the capacity in the wall-concrete structure in steal of using the existing form which has problems such as, excessive exposure of cement, the loss of labor when it is constructed or disjointed, and it's economical efficiency compared with that of EURO Form. AFR panel passes the KS F 8006 test, and as a result of field test, it's displacement is satisfied with Specification. And using AFR panel is more economical than that of EURO Form because saving labor cost which plays a major part in cost saving in formwork is more effective in retrenching total cost than increment of material cost.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.555-560
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• 2002

Brazing of Al to Cu using AI-Si-Mg-Bi brazing alloy has been carried out in the vacuum furnace. In the bonded interlayer, there were two kinds of intermetallic compounds. One of these intermetallic compounds was e phase and the other was b phase. The growth of b phase was controlled by diffusion Al into Cu. Deformation behavior of Al-Cu brazing joint was brittle without deformation of the base metal. Shear strength of the joint was only about 20MPa. The shear specimen broken in the intermetallic compound, which was mainly e phase. Shear strength did not depend on the bonding temperature.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.38 no.3
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• pp.51-51
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• 2001

본 논문에서는 CMOS 로직과 pass-transistor logic(PTL)의 장점만을 가진 새로운 복합모드로직(Compound Mode Logic)을 제안하였다. 제안된 로직은 VLSI설계에서 중요하게 부각되고 있는 저전력, 고속 동작이 가능하며 실제로 전가산기를 설계하여 측정 한 결과 복합모드 로직의 power-delay 곱은 일반적인 CMOS로직에 비해 약 22% 개선되었다 제안한 복합모드 로직을 이용하여 고성능 32×32-bit 곱셈기를 설계 제작하였다. 본 논문의 곱셈기는 개선된 사인선택(Sign Select) Booth 인코더, 4-2 및 9-2 압축기로 구성된 데이터 압축 블록, 그리고 carry 생성 블록을 분리한 64-bit 조건 합 가산기로 구성되어 있다. 0.6um 1-poly 3-metal CMOS 공정을 이용하여 제작된 32×32-bit 곱셈기는 28,732개의 트랜지스터와 1.59×l.68 ㎜2의 면적을 가졌다. 측정 결과 32×32-bit 곱셈기의 곱셈시간은 9.8㎱ 이었으며, 3.3V 전원 전압에서 186㎽의 전력 소모를 하였다.

• Journal of the Korean Ceramic Society
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• v.34 no.11
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• pp.1099-1106
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• 1997

In the present study, the effect of TiB2 addition on the sintering behavior of ZrB2 ceramics was studied with hot pressing under Ar atmosphere. Hot pressing experiments were carried out in graphite dies at the 1$700^{\circ}C$, 180$0^{\circ}C$ under Ar atmosphere. The sintering density increased with increasing TiB2 contents. With the addition of 10wt% TiB2 almost theoretical density could be achieved by hot-pressing at 180$0^{\circ}C$. Zr-Ti-Fe-B compound in liquid phase was observed from the EDS and WDS analysis. It was considered that sinterability was enhanced due to the mass transfer through liquid phase formed at the sintering temperature. In addition of TiB2, transition metal of groups IV, substitutional solid solution could be formed.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.2
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• pp.145-150
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• 2011

There is problem to reduce the car body weight for improving fuel consumption and $CO_2$ generation. As one of the solution, the multi material car body concept using aluminum alloys and high strength steels is proposed recently. Therefore, new welding processes by which these dissimilar material can be joined in high reliability and productivity are demanded. Laser spot welding was developed for joining of dissimilar metals. In the present work, Laser spot welding of zinc coated steel and aluminum alloy was investigated, and the process parameters were studied. Otherwise, the influences of process parameters on the weldability, the formation of intermetallic compound layer and the mechanical properties have been investigated. When intermetallic compound layer thickness was more than 1mm, specimen was failure in the interface.