• Title/Summary/Keyword: metallurgical

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Multidirectional Liquid Crystal Orientation by Using Ion Beam Irradiation

  • Ahn, Han-Jin;Kim, Kyung-Chan;Kim, Jong-Bok;Hwang, Byung-Har;Baik, Hong-Koo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07a
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    • pp.543-546
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    • 2005
  • We have investigated the alignment ability of multi-domains by using ion beam irradiation on diamond-like carbon (DLC) thin film layers. The DLC thin films were deposited by plasma enhanced chemical vapor deposition (PECVD) system and the low energy ion beam is irradiated from Kaufman type ion gun. The direction of liquid crystal alignment is varied by the direction of Ar ion beam irradiation.

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Alignment property change in DLC alignment layer containing various hydrogen concentration

  • Kim, Jong-Bok;Kim, Kyung-Chan;Ahn, Han-Jin;Hwang, Byung-Har;Baik, Hong-Koo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07a
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    • pp.378-380
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    • 2005
  • Diamond like carbon (DLC) films are known that they show homogeneous alignment property when they are irradiated by Ar ion beam. The DLC films in most of studies were deposited by CVD and contain large mount of hydrogen. In order to identity the hydrogen effect on alignment property, DLC films is deposited by RF magnetron sputter using various ratio of Ar and H2 as reactive gas. DLC films are characterized by FT-IR, Raman and contact angle. Alignment property is estimated by measuring pretilt angle.

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Sintering Behavior of Mechanically Alloyed Titanium - Titanium Nitride Nanocomposite Powders

  • Dabhade, Vikram V.;Panigrahi, B.B.;Godkhindi, M.M.;Rama Mohan, T. R.;Ramakrishnan, P.
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09a
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    • pp.274-275
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    • 2006
  • The sintering behavior of titanium-titanium nitride nanocomposite powders has been studied by dilatometry. Titanium. titanium nitride nanocomposite powders were produced by the reactive milling of micron sized titanium powder $(12\;{\mu}m)$ in nitrogen atmosphere. The Ti-TiN nanocomposite powders milled for various durations along with the initial micron sized Ti powders were then sintered in the temperature range of $450-1000^{\circ}C$ by a constant rate of heating $(10^{\circ}C/min)$. The linear shrinkage, shrinkage rate, activation energy for sintering and microstructure has been studied and discussed as a function of milling time.

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Exchange anisotropy depending on Interfacial Structure of the NiO/NiFe bilayers

  • Suh, S.J.;Kwak, J.O.;J.C.Ro;Kim, Y.S.;Park, G.S.
    • Proceedings of the Korea Association of Crystal Growth Conference
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    • 1998.06a
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    • pp.87-90
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    • 1998
  • ABSTRACT- we have analyzed the effect of microstructure and interface conditions on the anisotropic exchange filelds of NiO/NiFe bilayers. The NiO films were deposited by R.F. magentron sputtering. By using different atgon pressure NiO Films, Grain Size And Surface Roughness Of NiO can be manipulated. The exchange field is enhanced in the small granined NiO And This Increment Is Based On The Formation Of Small Domains In NiO

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A Study on the Hydrogenation Properties of TiNi Alloy Fabricated by Mechanical Alloying Method (기계적합금법에 의해 제조된 TiNi합금의 수소화반응특성에 관한 연구)

  • Ahn, Hyo-Jun;Kim, Bo-Su;Hwang, Jin-Hwan;Ahn, In-Shup;Kim, Ki-Won;Hur, Bo-Young
    • Transactions of the Korean hydrogen and new energy society
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    • v.5 no.2
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    • pp.73-79
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    • 1994
  • The hydrogenation behavior of Ti-Ni powders prepared by mechanical alloying in a high energy ball mill have been investigated by P-C isotherm curves, DSC(differential scanning calorimetry), X-ray diffractometer, SEM(scanning electron microscope). Amorphous TiNi phase was formed after 10 milling hours. The hydrogen storage capacity gradually decreased as a function of mechanical alloying time. There appears the DSC endothermic peak due to hydrogen evolution of amorphous hydride phase.

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The Effect of Aging Treatment on the Corrosion Resistance in Super Duplex Stainless Steel with Added W (텅스텐이 첨가된 슈퍼 2상 스테인리스강의 내식성에 미치는 시효처리의 영향)

  • Kim, Soo-Chun;Choi, Han-Gul;Kim, Yun-Kyu;Park, Young-Tae;Lee, Jong-Mun;Park, Jin-Hwan;Kang, Chang-Yong
    • Journal of Ocean Engineering and Technology
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    • v.23 no.6
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    • pp.87-92
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    • 2009
  • The effect of aging on the precipitation of the $\sigma$ phase and the corrosion resistance in tungsten substituted super duplex stainless steels was investigated. The volume fraction of the $\sigma$ phase and the current density increased with aging at temperatures up to $750^{\circ}C$ and then decreased. With an increase in aging time, the volume fraction of the $\sigma$ phase and the current density also increased. The $\sigma$ phase hardly influenced the corrosion resistance. With the substitution of tungsten for molybdenum in super duplex stainless steel, the volume fraction of the $\sigma$ phase and the current density decreased remarkably.

A Study on the High Temperature Strength of Ferritic Stainless Cast Steels (페라이트계 스테인레스 주강의 고온강도에 관한 연구)

  • Ann, Soo-Jung;Kang, Mi-Ri;Seo, Do-Soo;Kim, Yong-Hyun;Lee, Kwang-Hak;Kim, Heung-Shik
    • Journal of Korea Foundry Society
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    • v.18 no.6
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    • pp.563-569
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    • 1998
  • A Study on microstructure and elevated temperature strength of 18Cr-2Mo ferritic stainless steel castings strengthened by alloying small amounts of titanium and carbon, has been conducted. The morphology of titanium carbides showed spherical in shape and their distribution depended on the amount of alloying elements. Maximum density ($7{\times}10^5/cm^2$) of titanium carbides has been formed in the alloy containing 2.0 wt.% titanium and 0.5 wt.% carbon as alloying elements and the size of carbide particles is in the range of 0.5 to $3.0\;{\mu}m$. High temperature tensile and fatigue strength of this alloy were the highest among the alloys tested in this research. The fracture mode of the alloys containing alloying elements less that 2.0 wt.% titanium and 0.5 wt.% carbon showed intercrystalline fracture at room temperature, while the alloys containing higher amounts of alloying elements showed transcrystalline fracture. All of the alloys showed creep or ductile rupture mode at elevated temperature.

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Microstructure of Rapidly Solidified Al 6061 Flake Powder and It's Extrudate (Al 6061 Flake 파쇄분말 및 압출재의 미세조직)

  • Cho S.S.;Jin D.Z.;Lee J.G.;Yim K.H.;Lee B.S.;Eum S.H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1999.05a
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    • pp.47-55
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    • 1999
  • The microstructure of Al 6061 powder milled from rapidly solidified flake and it's extrudate were investigated. The grain size of flake was about $0.8-1.5{\mu}m$ and the powder shape was spherical due to the milling condition. In the microstructure of extrudate, the unbinded powder boundary was found the front part of extrudate and all the macroscopic defects such as boundary defect, holes or cracks was not observed except the front part. It was found that the extrudate except 60cm of front part was useful part.

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Application of S-HGMS and chemical coupling technology in river water treatment

  • Zhao, Xin;Li, Su-qin;Han, Shuai-shuai;Zhang, Peng;Jin, Jian-jiang;Guo, Peng-hui
    • Progress in Superconductivity and Cryogenics
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    • v.22 no.2
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    • pp.12-16
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    • 2020
  • Circulating cooling systems consume a lot of water, and most of the water from river, which contains a large amount of Ca2+, Mg2+, et al, and has the characteristics of high hardness and large turbidity. The water can form scale on the surface of the heat exchanger and the pipes, which would reduce the heat transfer efficiency and affect the heat exchanger's length of service. In this study, the Superconducting High Gradient Magnetic Separation (S-HGMS) technology was used in river water treatment and the effects of agent A, agent B, and S-HGMS on the removal of hardness and turbidity were discussed. The results showed that the hardness removal rate reached 71.3% and the turbidity was decreased to 0.5 NTU.

Present State and Prospect on Reutilization of Metal - Bearing Solid Wastes in China

  • Chai, Liyuan;Chen, Weiliang;Min, Xiaobo;He, Dewen;Zhang, Chuanfu
    • Proceedings of the IEEK Conference
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    • 2001.10a
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    • pp.183-187
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    • 2001
  • Present states on reutilization of metal-bearing solid wastes in China including metal-containing gangue, red mud, nonferrous metallurgical slag or residue, arsenical slag, steel - iron slag, waste batteries, were described in detail. The wastes pile up at a large quantity, resulting in seriously potential harm to environment. Most of these wastes, however, contain valuable metals, which are regarded as important secondary resources for extracting metals. Waste slag and batteries with a high grade of metals are treated by a hydro-based and / or pyre-based method for extracting valuable metals. While gangue and waste slag with a low grade are as a raw material in architecture field. In the future, a novel technology, such as high-grads magnetization separation technique and biological technique, will be designed to treat these wastes for protecting environment and recycling valuable components. These wastes, furthermore, are synthetically reutilized to produce various architectural materials, including glass and ceramics.

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