• Korean Journal of Materials Research
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• v.23 no.1
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• pp.41-46
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• 2013

The microstructural evolution of AA1050/AA6061 complex aluminum alloy, which is fabricated using an accumulative roll-bonding (ARB) process, with the proceeding of ARB, was investigated by electron back scatter diffraction (EBSD) analysis. The specimen after one cycle exhibited a deformed structure in which the grains were elongated to the rolling direction for all regions in the thickness direction. With the proceeding of the ARB, the grain became finer; the average grain size of the as received material was $45{\mu}m$; however, it became $6.3{\mu}m$ after one cycle, $1.5{\mu}m$ after three cycles, and $0.95{\mu}m$ after five cycles. The deviation of the grain size distribution of the ARB processed specimens decreased with increasing number of ARB cycles. The volume fraction of the high angle grain boundary also increased with the number of ARB cycles; it was 43.7% after one cycle, 62.7% after three cycles, and 65.6% after five cycles. On the other hand, the texture development was different depending on the regions and the materials. A shear texture component {001}<110> mainly developed in the surface region, while the rolling texture components {011}<211> and {112}<111> developed in the other regions. The difference of the texture between AA1050 and AA6061 was most obvious in the surface region; {001}<110> component mainly developed in AA1050 and {111}<110> component in AA6061.

• Proceedings of the Materials Research Society of Korea Conference
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• 1999.11a
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• pp.111-111
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• 1999

• Proceedings of the Korean Vacuum Society Conference
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• 2009.08a
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• pp.146-146
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• 2009

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.10a
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• pp.374-377
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• 2008

High temperature deformation behavior and texture evolution during ECAP(equal channel angular pressing) of Zn-0.3Al alloy were investigated in this study. ECAP was conducted at temperatures from $40^{\circ}C$ to $160^{\circ}C$ on the plate type specimen of 5mm thickness and 20mm width. The specimens obtained by ECAP showed typical texture with basal poles tilted away from the ND toward ED. A series of compression tests was carried out at temperatures from RT to $200^{\circ}C$ under the strain rate from 0.03 to 10/s. With the strain rate increased, serration behavior was observed to be prominent.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.05a
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• pp.105-108
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• 2003

Sheets of aluminum alloy 1100 were asymmetrically cold rolled in a rolling mill with different roll speeds. In order to promote the shear deformation during asymmetrical rolling, cold rolling without lubrication was performed. The evolution of texture components during asymmetrical rolling was investigated by the calculation of the orientation distribution function (ODF) using the monoclinic sample symmetry. The strain state during asymmetrical rolling was tackled by means of FEM calculations. Asymmetrical rolling gave rise to the development of pronounced strain gradients throughout the thickness layers which resulted in the formation of strong texture gradients in the aluminum sheet.

• Transactions of Materials Processing
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• v.12 no.3
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• pp.244-250
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• 2003

Sheets of aluminum alloy 1100 were asymmetrically cold rolled in a rolling mill with different roll speeds. In order to promote the shear deformation during asymmetrical rolling, cold rolling without lubrication was performed with a roll speed ratio of 1.5/l.0. The evolution of texture components during asymmetrical rolling was investigated by the calculation of the orientation distribution function (ODF) using the monoclinic sample symmetry. The strain state during asymmetrical rolling was tackled by means of FEM calculations. Asymmetrical rolling gave rise to the development of pronounced strain gradients throughout the thickness layers which resulted in the formation of strong texture gradients in the aluminum sheet.

• Transactions of Materials Processing
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• v.18 no.6
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• pp.448-452
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• 2009

Superplastic deformation behavior and texture evolution after equal channel angular pressing (ECAP) of Zn-0.3Wt%Al alloy were investigated in this study. ECAP was conducted at temperatures from $60^{\circ}C$ to $160^{\circ}C$ on the plate type specimens of 5 mm thickness and 20 mm width. The specimens obtained by ECAP showed typical texture with basal poles tilted away from the ND toward ED, which is called shear texture. Tensile tests were carried out at $100^{\circ}C$ for ECAPed specimens under the strain rate of 0.0002/s. After ECAP of the Zn-0.3Wt%Al alloy, elongation was dramatically increased up to 500% at $100^{\circ}C$. The effect of ECAP on the anisotropy in the superplastic deformation behavior was negligible.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.10a
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• pp.309-312
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• 2001

FEM simulating system of the cross-rolling texture formation offers a systematic and efficient way of exploring the relationship between the process variables and the state of plastic anisotropy of sheet product. Cross-rolled sheets possess higher average plastic strain ratios and lower planer anisotropy than those of the straight-rolled sheets. The employed model is a finite-element polycrystal model which each element used in FEM is assumed to be a crystal having different orientation by Takahashi. Texture development, deformation textures due to cross-rolling are predicted for face-centered cubic sheet metal. Crystal orientations are assigned on the basis of the pole figures obtained by X-ray diffraction. Development of anisotropy during cross rolling of an fcc sheet material is predicted theoretically with respected to flow stress and R-value in tensile test.

• 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.

• Animal Systematics, Evolution and Diversity
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• v.24 no.2
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• pp.215-218
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• 2008

Two new marine sponges in genus Suberites, S. hataedoensis n. sp and S. waedoensis n. sp have been collected from Hataedo Island and Waedo Island, Korea during 2005-2006. S. hataedoensis n. sp. is similar to S. durissimus in the spicule composition and texture. However, they differ in growth form, skeleton and surface. S. waedoensis n. sp. is similar to S. japonicus in spicule composition and skeleton. However, they differ in growth form, surface and texture.