• Title/Summary/Keyword: Division casting

검색결과 226건 처리시간 0.024초

4관능성 에폭시 수지/불소를 함유한 에폭시 수지 블렌드 시스템의 경화거동 및 파괴인성에 관한 연구 (Studies on Curing Behavior and Fracture Toughness of Tetrafunctional Epoxy Resin/Fluorine-containing Epoxy Resin Blend System)

  • Jin, Fan-Long;Lee, Jae-Rock;Park, Soo-Jin;Shin, Jae-Sup
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 2002년도 추계학술발표대회 논문집
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    • pp.273-275
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    • 2002
  • In this studies, curing behavior and mechanical properties of tetrafunctional epoxy resin (4EP)/ fluorine-containing epoxy resin (FEP) blend systems was investigated with 4, 4'-diaminodiphenol methane (DDM) as a curing agent. The cure activation energies $(E_a)$) were studied by Flynn-Wall-Ozawa's equation with dynamic DSC method. For the fracture toughness of the casting specimens, the critical stress intensity factor ($K_{IC}$) and the specific fracture energy ($G_{IC}$) were determined by fracture toughness test.

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Synthesis and Properties of the Vertical Alignment Materials containing Liquid Crystal-like Side Chain

  • Lee, J.B.;Kang, K.H.;Kim, Y.B.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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    • pp.389-392
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    • 2005
  • Poly(amic acid) precursors were prepared by mixing various main chain dianhydrides, main chain diamines and side chain diamines. The side chain diamine has an alkylbicyclohexyl group as a side chain. The copolyimide films, produced by casting the poly (amic acids) solution, exhibited the vertical alignment property without the rubbing process in the range of the curing themperature from $90^{\circ}C$ to $240^{\circ}C$ for 1h. The thermal and surface properties of the poly(amic acids) depending on the curing temperature was examined.

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금형주조 구상흑연주철의 칠 형성 경향에 미치는 화학조성 및 열처리의 영향 (Effects of Alloying Elements and Heat-Treatment on the Tendency of Chill Formation of Ductile Cast Iron Produced by Metal Mold Cast)

  • 김석원;박진성;김기곤
    • 한국주조공학회지
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    • 제27권1호
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    • pp.24-30
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    • 2007
  • The effects of C, Si and RE additions on the tendency of chill formation of ductile cast iron obtained from metal mold casting were investigated. In case of metal mold cast, the ductile cast iron with 2.5%Si had pearlitic matrix, and specimens with 2.9%Si had bull's eye type regardless of C contents. As-cast specimen with a large amount of fine graphites could be obtained by adding 0.2% RE. Normalizing process was necessary to remove carbide and form a large amount of spheroidal graphites for the as-cast specimens. Good mechanical properties could be obtained by heat-treatment of as-cast specimens with pearlitic matrix. Normalizing the specimens with RE caused the reduction in mechanical properties.

Pb(Zr0.54Ti0.46)O3 + 0.2 wt% Cr2O3 + 1.0 wt% Nb2O5 조성의 압전 후막을 이용한 유니몰프형 캔틸레버 발전기(UCG)의 최적화 (Optimization of the Unimorph Cantilever Generator (UCG) Using Pb(Zr0.54Ti0.46)O3 + 0.2 wt% Cr2O3 + 1.0 wt% Nb2O5 thick films)

  • 김경범;김창일;윤지선;정영훈;남중희;조정호;백종후;남산;성태현
    • 한국전기전자재료학회논문지
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    • 제25권12호
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    • pp.955-960
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    • 2012
  • We fabricated piezoelectric unimorph cantilever generators (UCG) using $Pb(Zr_{0.54}Ti_{0.46})O_3$ + 0.2 wt% $Cr_2O_3$ + 1.0 wt% $Nb_2O_5$ (PZCN) piezoelectric thick films, which were produced by a tape casting method. The PZCN thick films were tailored with same width and thickness but different lengths from 7.7 to 57.7 mm in order to evaluate optimized UCG for energy harvesting device applications. When the length of PZCN film was increased, the resonance frequency of UCG was slightly increased from 7 Hz to 8 Hz, which could be due to enlarged area of the highly stiff piezo-ceramic film. However, the output power was proportionally increased with the length of PZCT film and it reached 4.68 mW (1.221 $mW/cm^3$) when the film's length was 57.7 mm under 25 g of tip mass at 8 Hz, which is sufficient for micro-scale device applications.

Future Outlook of Refractories for Iron and Steelmaking

  • Emi, Toshihiko
    • 한국세라믹학회지
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    • 제40권12호
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    • pp.1141-1149
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    • 2003
  • Refractory industry in technologically advanced countries has long been on gradual decline due to leveled-off steel production and decreasing unit consumption of refractories for steel. Notable technological achievements by refractory industry that contributed significantly to steel production are briefly reviewed covering from blast furnace, basic oxygen furnace to continuous casting. Future possibility to revitalize the refractory industry is discussed on the basis of the review, taking into account opportunities available in environment and energy related sector of industries.

테잎캐스팅을 이용한 전고체전해질 Li7La3Zr2O12 후막 제조 (Fabrication of Solid State Electrolyte Li7La3Zr2O12 thick Film by Tape Casting)

  • 신란희;손삼익;류성수;김형태;한윤수
    • 한국분말재료학회지
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    • 제23권5호
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    • pp.379-383
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    • 2016
  • A thick film of $Li_7La_3Zr_2O_{12}$ (LLZO) solid-state electrolyte is fabricated using the tape casting process and is compared to a bulk specimen in terms of the density, microstructure, and ion conductivity. The final thickness of LLZO film after sintering is $240{\mu}m$ which is stacked up with four sheets of LLZO green films including polymeric binders. The relative density of the LLZO film is 83%, which is almost the same as that of the bulk specimen. The ion conductivity of a LLZO thick film is $2.81{\times}10^{-4}S/cm$, which is also similar to that of the bulk specimen, $2.54{\times}10^{-4}S/cm$. However, the microstructure shows a large difference in the grain size between the thick film and the bulk specimen. Although the grain boundary area is different between the thick film and the bulk specimen, the fact that both the ion conductivities are very similar means that no secondary phase exists at the grain boundary, which is thought to originate from nonstoichiometry or contamination.

$Al-Ag_2Al$ 공정계 합금의 조성 및 냉각 속도에 따른 미세조직 고찰 (Influence of Cooling Rate and Alloy Composition on The Microstructural Evolution of Al-Ag Eutectic System)

  • 손성우;박진만;김태응;임가람;김원태;김도향
    • 한국주조공학회지
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    • 제29권2호
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    • pp.64-69
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    • 2009
  • In the present study the effect of cooling rate during solidification on the microstructural characteristics of Al-xAg (x = 31, 33, 35 at.%) in-situ binary eutectic composites has been investigated. To provide a wide range of cooling rate three different casting techniques, i.e. conventional casting, injection casting, and melt spinning have been used. The observed microstructure is very much dependent on the cooling rate. The fcc ${\alpha}$-Al and hcp $Ag_2Al$ phases exhibits an orientation of (111)Al//(0001)$Ag_2Al$, [1-10]Al//[11- 20]$Ag_2Al$. The microstructure of the melt-spun samples contains Widmanstatten structure resulting from solid-state transformation and nano scale two-phase structure resulting from solid-state phase separation. The microstructure of injection-cast samples contains eutectic structure and solid state phase-separated structure. On the other hand, conventional-cast samples exhibit a microstructure consisted of plate-type eutectic structure.

한국전통가구의 금속 손잡이 영문표기 연구 - 한국 및 서구를 중심으로 - (A Study on Terminology of Metal Handles in Traditional Korean Furniture - Focusing on Korean and Western Furniture -)

  • 문선옥
    • 한국가구학회지
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    • 제23권4호
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    • pp.449-459
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    • 2012
  • The article aims to making a comparison between traditional Korean and Western furniture metal handles to give the detail information of the handle terms by analyzing the related literature including internet and interviews. In terms of that, the Korean and Western metal handles are compared in the types, components, materials, methods, and terms affecting the development made by the craftsmen before the Industrial Revolution about the mid or late 18th century. As a result, first, ring and drop pull handles were mostly and wooden knobs were a little used to open the furniture doors and drawers. The Korean drop pulls, Deulswae, came out after the ring pulls, Gori, while the Western drops called loop or bail handles as well, came out before the ring pulls. Second, the components were composed by ring, Gori, loop or bail, Deulswae, Post, Baemok, washer, Baemokbatchim, and backplate, Deulswaebatchim. Most of the Western handles were fastened by the bolt and nut, while the post of two strips, Baemok, fastened the Korean metal handles. Third, the metal handles were created of brass and iron mostly, gilded gold and silver. Forth, the method were largely used by casting, engraving, forging, plating, and hammering in the Korean handles, and by casting, molding, engraving, and stamped in the Western handles. Finally, the terms such as "knobs, pulls, drops, ring and drop pulls, loop or bail handles, posts, washers, backplate, casting, molding, engraving, forging, plating, and stamped" were clarified by the two comparison in Korean and English.

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분사주조한 과공정 Al-Si-Fe 합금의 기계적 및 열적 특성에 관한 고찰 (A Study on the Mechanical and Thermal Properties of Spray-cast Hypereutectic Al-Si-Fe Alloys)

  • 박재성;류민;윤의박;윤우영;김권희;김명호
    • 한국주조공학회지
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    • 제26권3호
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    • pp.123-128
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    • 2006
  • Mechanical and thermal properties of spray-cast hypereutectic Al-20wt.%Si-xwt.%Fe alloys (x=0, 1, 3, 5) were investigated. After the spray-casting, hot extrusion was performed at $400^{\circ}C$. Intermetallic compound (${\beta}-Al_5FeSi$) and primary Si are observed in the spray-cast aluminum alloys. The size of primary Si and intermetallic compound of the spray-aluminum alloys became finer and more uniformly distributed than that of the permanent mold cast ones. Ultimate tensile strength of the spray-cast aluminum alloys increased by increasing Fe contents, but that of the permanent mold cast aluminum alloys decreased by increasing Fe contents possibly due to increased amount of coarse intermatallic compound. The coefficient of thermal expansion (CTEs) of the aluminum alloys became lower with finer primary Si and intermetallic compound, and this is attributed to the increased amount of interfacial area between the aluminum matrix and the phases of finer Si and intermetallic compound.

Electron Beam-induced Crosslinking and Characterization of Polycaprolactone Films in the Presence of Various Crosslinking Agents

  • Kang, Dong-Woo;Jung, Chan-Hee;Hwang, In-Tae;Choi, Jae-Hak;Nho, Young-Chang
    • 방사선산업학회지
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    • 제5권2호
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    • pp.107-112
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    • 2011
  • Electron beam-induced crosslinking of polycaprolactone (PCL) films containing various crosslinking agents (CAs) was investigated in this study. PCL films containing various CAs prepared by a solution casting method were irradiated by electron beams at various absorption doses and the irradiated PCL films were investigated in terms of their crosslinking degree, thermal and mechanical properties, and biodegradability. Based on the results of the crosslinking degree measurement, triallyl isocyanurate was found to be most effective for the electron-beam induced crosslinking of PCL films. The results of the UTM, DMA, and TMA revealed that the thermal and mechanical properties of the crosslinked PCL films were greatly improved in comparison to those of the pure PCL. The results of the enzymatic degradation test revealed that the biodegradability of the crosslinked PCL films was reduced in comparison to that of the pure PCL.