• Title/Summary/Keyword: Shear Texture

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Formation of Shear Texture and Microstructure in AA3004 Sheet (AA3004에서 전단변형 미세조직 및 집합조직의 형성)

  • 이강노;김종국;김훈동;황병복;허무영
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2002.05a
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    • pp.184-186
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    • 2002
  • The evolution of texture and microstructure during warm rolling and subsequent annealing in aluminium 3004 alloy sheet was investigated by X-ray texture measurements and microstructure observations. Warm rolling at 250$^{\circ}C$ led to the development of strong through thickness texture gradients with shear textures at the surface layer and a regular rolling texture in the center of the sheets. FEM simulations indicated that these texture gradients are caused by pronounced strain gradients throughout the sheet thickness. Upon recrystallization annealing, in the sheet center the characteristic cube-recrystallization texture developed, while in the surface layers with a pronounced shear texture continuous recrystallization took place which led to the formation of a very fine grained microstructure. It is concluded that the very complex strain history in the near-surface layers together with the resulting high work-hardening rate gave rise to the formation of the ultra-fine grains with an average size smaller than 2$\mu\textrm{m}$.

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Effect of Initial Texture on the Evolution of Warm Rolling Texture and Microstructure in Aluminum Alloy Sheet (알루미늄 판재의 온간압연 집합조직과 미세조직에 미치는 초기 집합조직의 영향)

  • Kim H. D.;Huh M. Y.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2001.10a
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    • pp.138-141
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    • 2001
  • The evolution of lectures and microstructure during the warm-rolling and subsequent annealing in aluminum 3004 alloy sheets was investigated by employing X-ray texture measurements and microstructure observations. Whereas the typical $\beta$-fiber orientations with the strong Bs-orientation $\{112\}<110>$ formed in the normally cold-rolled specimen, the warm-rolling at $250^{\circ}C$ led to the development of a strong through thickness texture gradient which was characterized by shear texture at the surface layer and rolling textures at the center layer After warm rolling, ultra-fine grains formed in the thickness layer with shear texture components. Upon recrystallization annealing, the $\{001\}<100>$ Cube-texture developed at the expense of normal rolling texture components the rise to the formation of corase recrystallized grains. However, in the layer with shear texture components the continuous recrystallization took place and the fine grain size persisted even after recrystallization annealing.

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Changes of Salmon Meat Texture During Semi-Drying Process (조미 반건조 제품 가공 공정에 따른 연어육 Texture의 변화)

  • You Byeong-Jin
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.30 no.2
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    • pp.264-270
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    • 1997
  • To obtain basic data for processing semi-dried salmon meat product, the results that were measured the textural properties of salmon meat during salting, sugaring and drying process followed. Drying time and temperature were longer, the moisture amount of salmon meat were reduced. Hardness of salmon meat was direct proportion to shear stress, but hardness was inverse proportion to cohesiveness during drying process. After sugaring and salting salmon meat, drying time was longer, hardness and shear stress of salmon meat were increased. The sensory evaluation of the textures of sugaring salmon meat dried for 3 hrs showed slightly good. In the changes of texture of salmon meat during steaming hardness and shear stress of salmon meat dried for 4 hrs were higher than that dried for 10 hrs. And steaming time was longer, hardness of salmon meat dried for 4 hrs was decreased and cohesiveness was not changed.

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Effects of Blanching, Chemical Dipping, Freezing Methods and Storage Period on Quality of Frozen Mushrooms (Blanching, Chemical Dipping, 냉동방법 및 저장기간이 냉동 양송이의 품질에 미치는 영향)

  • Lee, Young-Chun;Lee, Kyung-Hae
    • Korean Journal of Food Science and Technology
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    • v.20 no.4
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    • pp.536-540
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    • 1988
  • Effects of blanching time, chemical dipping, freezing method and storage period on texture, color and yield of frozen whole and sliced mushrooms were investigated, and the results are summarized as follows; Frozen whole mushrooms blanched for 5min. had markedly tougher texture than mushrooms blanched for 1 or 2 minutes. As the storage time of frozen mushrooms increased from 3 to 6 months, shear press values increased very significantly. The texture of Freon frozen and plate frozen mushrooms was similar after 3 months storage. Blanching time did not affect texture of frozen sliced mushrooms significantly, but storage time did. The results of sensory evaluation for texture were in good agreement with shear press values. Chemical dipping methods were effective in maintaining desirable color of frozen whole and sliced mushrooms stored for 3 months. The yield of frozen whole mushrooms was significantly increased by shortening blanching time in combination with chemical dipping. Sliced mushrooms required at least 2 min. blanching, to avoid excessive breakage in mechanical slicing operation, for better yield.

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Texture and Microstructure in AA3004 after Continuous Confined Strip Shearing (CCSS 변형된 AA 3004 판재의 집합조직과 미세조직)

  • 김훈동;정영훈;황병복;최호준;허무영
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2002.05a
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    • pp.181-183
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    • 2002
  • A new deformation process termed "continuouis confined sup shearing" (CCSS) has been developed for shear deformation of metallic sheets. The tools of CCSS were designed to provide a constant shear deformation of the order of 0.5 per pass while preserving the original sheet shape. In order to clarify the evolution of texture and microstructure during CCSS, strips of the aluminum alloy AA3004 were deformed by CCSS in up to three passes. FEM results indicated that CCSS provides a quite uniform shear deformation at thickness layers close to the strip center, although the deformation is not homogeneous in the die channel, in particular at the surface layers. The rolling texture of the initial sheet decreased during CCSS, and preferred orientations along two fibers developed. However, with an increasing number of CCSS passes the deformation texture did not develop futher. The evolution of annealing textures depended on the number of CCSS passes. A strong {112}<110> component in the deformation texture led to the formation of a strong {111}<112) orientation in the annealing texture. Observations by TEM and EBSD revealed the formation of very fine grains of ∼1.0$\mu\textrm{m}$ after CCSS.

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Evolution of shear texture during hot rolling of AA1050 aluminum sheet. (AA1050 알루미늄 합금의 열간 압연 시 전단집합조직의 형성)

  • Hang, G.C.;Kim, H.C.;Huh, M.Y.;Lee, J.S.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2006.05a
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    • pp.222-225
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    • 2006
  • The effect of lubrication on the development of textures and Microstructure was studied by different lubricating condition during hot rolling of AA1050 aluminum alloy. Hot rolling without lubrication led to the evolution of the pronounced through-thickness texture gradients, whereas hot rolling with lubrication gave rise to the formation of uniform rolling texture in the whole thickness layer. The variation of texture and microstructure according to hot rolling condition are investigated by X-ray diffractometer (XRD) and Electron Back-Scattered Diffraction (EBSD). The experimental results were discussed base on the finite element method (FEM) simulation. FEM calculation reveals that a larger friction between roll and sheet causes the deviated strain state from a plane strain leading to the formation of shear textures in the thickness layers close to the surface.

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Evolution of Strain States and Textures During Rolling with Various Conditions (압연조건에 따른 변형률 상태의 변화와 집합조직의 형성)

  • Kang, H.G;Huh, M.Y
    • Transactions of Materials Processing
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    • v.15 no.7 s.88
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    • pp.479-484
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    • 2006
  • The evolution of strain states and textures during rolling with various conditions was investigated by finite element method (FEM) simulations and measurements of rolling textures. Symmetrical rolling with a high friction gives rise to a strong variation of shear strains in rolled sample leading to the formation of texture gradients throughout the thickness layers. A small variation of shear strains during rolling with a well lubrication condition leads to the formation of a fairly homogeneous rolling texture throughout the sheet thickness. During asymmetrical rolling, a proper control of rolling parameters provides the evolution of a fairly homogeneous shear texture throughout the whole sheet thickness.

Effect of Groove Pressing on Deformation Texture in Aluminum (그루브 압축이 알루미늄 집합조직에 미치는 영향)

  • 김영석;박종진
    • Transactions of Materials Processing
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    • v.9 no.4
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    • pp.421-427
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    • 2000
  • The present study has focused on the development of shear textures during groove pressing in an aluminum alloy sheet. The shear components 23 and 13 developed during the groove pressing process. The process consisting of two steps of grooving and flattening each effectively gave rise to a high shear deformation In the sheet without reduction in thickness. The main texture component obtained from the process was the rotated Bs-orientation. The evolution of shear components during the groove pressing caused an increase in R-value of aluminum sheet comparing to a normally processed rolled sheet.

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Improvement of shear deformation by controlling reduction per a rolling pass during asymmetrical cold rolling in AA 5052 (AA5052 판재의 비대칭 냉간압연 시 압연 패스당 압하율 제어에 의한 전단 변형 향상)

  • Kang, H.G.;Han, Y.H.;Huh, M.Y.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2007.05a
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    • pp.226-228
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    • 2007
  • During asymmetrical cold rolling in AA 5052 sheet a reduction per a rolling pass was varied to investigate the effect of the ratio of the contact length between the roll and sample ($l_c$) to the sheet thickness (d) on the formation of shear textures. In order to intensify the shear deformation during asymmetrical rolling, AA 5052 sheet was asymmetrically cold rolled without lubrication by using different roll velocities of upper and lower rolls. Asymmetrical rolling with $l_c$/d=1.8 led to the formation of texture gradients throughout the sheet thickness in which the outer thickness layers depicted shear textures and the center thickness layers displayed a rolling texture. Asymmetrical rolling with $l_c$/d=3.1 gave rise to the formation of shear textures in the whole through-thickness layer. The strain states associated with asymmetrical rolling were investigated by the finite element method (FEM) simulation. FEM results indicated that the evolution of deformation texture in a thickness layer is strongly governed by integrated values of strain rates and along the streamline in the roll gap.

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