• Title/Summary/Keyword: crystal texture

검색결과 144건 처리시간 0.027초

판재의 초기집합조직이 평면변형률 스트레칭 변형에 미치는 영향 (Effect of Initial Textures on the Plane Strain Stretching)

  • 배석용;이용신
    • 소성∙가공
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    • 제7권5호
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    • pp.459-464
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    • 1998
  • Effect of the several initial textures such as random texture, rolling texture and cube texture, on the plane strain stretching was studied by interpretation of the finite element method. The calculation of yield locus indicated that the sheet oriented in the cube texture exhibits easy yielding on uniaxial stress state whereas the sheet having either a random or the rolling texture exhibits easy yielding on shear deformation. Upon stretching tests, the thickness strain at the center region contacting the punch was identical regardless of the initial textures while the dependence of the thickness strain on the initial texture was found in the other regions. In general punch loads required or the sheet with an initial cube texture was as expected from calculated yield locus, lower than those for the others.

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Wide viewing angle of reflective cholesteric liquid crystal display

  • Kwon, Jang-Un;Kang, Dae-Seung
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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    • pp.608-610
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    • 2003
  • In the paper, we have investigated the reflective cholesteric display based on the polymer stabilization. The bistability in the polymer stabilized cholesteric texture(PSCT) films was observed and wider viewing angle was achieved due to imperfect planar texture.

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B첨가에 의한 강 및 주철의 기계적 성질에 미치는 효과 (A Study of Effects Exerted on the Mechanical Properties of the Steel and Cast Iron by the Adding B)

  • 황용연;권오헌
    • 대한기계학회논문집
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    • 제18권9호
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    • pp.2368-2373
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    • 1994
  • The advancement of the mechanical properties of metal materials caused by a recent high technology contributes to the stability and productivity of mechanical structures. However, the advanced mechanical properties depends on the conditions of crystal boundaries and the improvement of the texture. Although the tensile strength and a hardness of a steel would be increased by the adding B, it seems to be a marked decreases of the toughness which caused in the weaken workability. This study is concerned with a characteristics of the B compound which will be mixed with $H_3BO_3$ and the metallic magnesium. What affected in the mechanical property and texture is checked by the strength and the texture test. As a result, it is shown that the improvement of the mechanical property and the texture homogeneity. In addition, it seems that a molten metal which is added by the B compound is deoxized and cleansed.

FCC 다결정재의 집합조직 발전에 따른 이방성의 변화 (Anisotropy due to Texture Development in FCC Polycrystals)

  • 김응주;이용신
    • 대한기계학회논문집A
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    • 제20권5호
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    • pp.1516-1523
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    • 1996
  • The present study is concerned with the development of anisotropy and deformation texture in polycrystals. The individual grain in an aggregate is assumed to experience the viscoplastic dedformation with crystallographic slip that unsure uniquenessof the active slip systems and shearing rate onthese systems. Two different methods for updating the grain orientation are examined. Texture development for some deformation modes such as plane strain compression, uniaxial tension and simple shear are found. Changes in anisotropic flow potential due to texture development during large deformation are also given. Anisotropic behavior of polycrystals with defferent textures are examined.

Texture Characteristics of TiN Film by Electron Backscatter Diffraction

  • Jeong, Bong-Yong
    • 대한금속재료학회지
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    • 제50권12호
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    • pp.867-871
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    • 2012
  • The microstructure and texture of TiN coatings on a Ni-based super-alloy were characterized by the automated version of electron backscatter diffraction (EBSD), EBSD techniques were used to investigate the very fine TiN grain shape and crystal orientation. This study confirmed that EBSD techniques provide a very useful tool for characterization of coating materials. The TiN grains had a special texture, a {001}-fiber texture in the coating layer. It was also found that, in severe environments, the coating performance of equiaxial and randomly oriented TiN is superior to that with columnar structures.

단결정 밀리 부품의 입체성형 해석에 관한 연구 (A Study on Analysis for Bulk Forming of a Single Crystal Milli-Product)

  • 이용신;김용일
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2001년도 춘계학술대회 논문집
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    • pp.245-249
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    • 2001
  • This paper is concerned with numerical analyses for bulk forming of a single crystal milli-product, whose typical size ranges from a few hundreds ${\mu}m$ to a few mm. The numerical formulation invoked in this paper combines the crystal plasticity theory considering texture development and the ductile damage mechanics for growth of micro voids, since orientation development and growth of micro voids become the primary factors for bulk forming of milli-size products. As applications, milli-extrusion of a single crystal round bar and milli-rolling of a single crystal plate are simulated and the results are discussed in detail.

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CRYSTAL ORIENTATION OF ELECTROLESS COPPER AND ELECTRODEPOSITED NICKEL FILMS ON THE MAGNETS

  • Chiba, Atsushi;Kobayashi, Katsuyoshi;Miyazaki, Hiroki.;Yoshihara, Sachio;Wu, Wen-Chang
    • 한국표면공학회지
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    • 제32권3호
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    • pp.372-376
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    • 1999
  • The deposited Cu film on the ferrite magnet was more deposited comparing with that on the plastic magnet. The Cu film became thicker on the S pole comparing with that on the N pole in the both of magnets. The thickness and texture coefficient of deposited copper film affected with direction of line of magnetic force. The difference of pole had little or no effect to the texture coefficient of deposited nickel film. The reaction rate on ferrite magnet and S pole was faster comparing with that on plastic magnet and N pole.

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Yield function of the orthotropic material considering the crystallographic texture

  • Erisov, Yaroslav A.;Grechnikov, Fedor V.;Surudin, Sergei V.
    • Structural Engineering and Mechanics
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    • 제58권4호
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    • pp.677-687
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    • 2016
  • On the basis of the energy approach it is reported a development of the yield function and the constitutive equations for the orthotropic material with consideration of the crystal lattice constants and parameters of the crystallographic texture for the general stress state. For practical use in sheet metal forming analysis it is considered different loading scenarios: plane stress and plane strain states. Using the proposed yield function, the influence of single ideal components on the shape of yield surface was analyzed. The six texture components investigated here were cube, Goss, copper, brass, S and rotated cube, as these components are typically observed in rolled sheets from FCC alloys.

CONTROL OF HARDNESS OF OIL-WAX GELS BY A NOVEL BRANCHED WAX AND APPLICATION TO LIPSTICKS

  • Yoshida, K.;Shibata, M.;Ito, Y.;Nakamura, G.;Hosokawa, H.
    • 대한화장품학회:학술대회논문집
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    • 대한화장품학회 2003년도 IFSCC Conference Proceeding Book I
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    • pp.469-479
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    • 2003
  • A novel branched wax has been developed for the control of the hardness of oil-wax gels. Using this wax, glossier application and smoother texture but tough lipstick can be obtained. Oil-wax gels are oily solids composed of liquid and crystalline solid oils (waxes). They are widely used in various cosmetic products, especially lipsticks. The control of gel hardness is one of the most important techniques in improvement of the lipstick quality. Addition of small amounts of commercial branched paraffin wax (e.g. microcrystalline wax, b-PW) to n-paraffin wax (n-PW) has been commonly used to increase gel hardness. However, gel hardness is very sensitive to the quantity of b-PW and the gel obtained is not always hard enough for practical use. In this study we examined the relationship between the gel hardness and the properties of the wax crystal in the gel. We have found that, when b-PW is added to n-PW, the wax crystal size becomes smaller (hardening the gels) and its crystallinity is decreased (softening the gels) simultaneously. Considering this result, we have developed a novel branched wax, Bis(polyethylenyl)- tetramethyldisiloxane (named ESE). ESE molecules are composed of a central tetramethyldisiloxane unit (branch unit) with polyethylene units at both ends. The central unit may suppress crystal growth while the ends are expected to prevent a decrease in wax crystallinity during crystallization. When ESE is added to n-PW, the wax crystal obtained becomes smaller without decreasing in crystallinity; consequently, the gel hardness is dramatically increased. By using ESE, the total amount of wax in a lipstick can be decreased by 30% without spoiling the stick toughness, thereby achieving glossy application and smooth texture.

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