• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.08a
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• pp.19-24
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• 2004

Symmetrical and asymmetrical rolling was performed in AA 1050 sheets. Asymmetrical rolling was carried out by using different roll velocities of upper and lower rolls. The effect of the reduction per rolling pass on the formation of textures and microstructures during symmetrical and asymmetrical rolling was studied. In order to intensify the shear deformation, symmetrical and asymmetrical rolling was carried out without lubrication. The strain states associated with rolling were investigated by simulations with the finite element method (FEM). A fairly homogeneous residual shear strain throughout the sheet thickness was observed after asymmetrical rolling. Symmetrical rolling with a high friction gave rise to a strong net shear strain gradient in the sheet thickness.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.219-221
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• 2006

Asymmetrical rolling was performed by rolling AA 1050 sheets with different velocities of upper and lower rolls. In order to study the effect of roll gap geometry on the evolution of strain states and textures during asymmetrical rolling, the reduction per rolling pass was varied. After asymmetrical rolling, the outer thickness layers depicted shear textures and the center thickness layers displayed a random texture. With decreasing reduction per an asymmetrical rolling pass, the thickness layers depicting shear textures increases. The strain states associated with asymmetrical rolling were investigated by simulations with the finite element method (FEM).

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10a
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• pp.156-158
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• 2003

Sheets of aluminum alloy 1050 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 variation of the shear strain state during asymmetrical rolling was tackled by means of FEM calculations. Asymmetrical rolling gave rise to the development of pronounced residual shear strain gradients throughout the thickness layers.

• 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.

• 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.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.460-462
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• 2005

Asymmetrical rolling was performed with different working roll speeds of upper and lower rolls. In order to promote the shear deformation during asymmetrical rolling, various deformation parameters of initial sheet thickness, rolling reduction, roll speed ratio and roll radius are considered. The evolution of texture during asymmetrical rolling was shown by the calculation of orientation distribution function (ODF). The effect of deformation parameters on shea. deformation were investigated by simulations with the finite element method (FEM). 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 sheet.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.10a
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• pp.84-86
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• 2007

Aluminum sheets were asymmetrically cold rolled without lubrication by using different roll velocities of upper and lower rolls in order to intensify the shear deformation. During asymmetrical cold rolling of aluminum sheets, a reduction per a rolling pass, initial sheet thickness, roll diameter, roll velocity ratio were varied to investigate the effect of rolling parameters. The formation of through thickness shear texture was related to the ratio of the contact length between the roll and sample($l_c$) to the sheet thickness(d). 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 $\dot{\varepsilon}_{13}$ and $\dot{\varepsilon}_{11}$ along the streamline in the roll gap.

• 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.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.10a
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• pp.64-66
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• 2007

Asymmetric rolling, where circumferential velocities of the upper and lower rolls differ, can be one method to change texture of magnesium alloy sheet by introducing shear deformation throughout the thickness of a sheet. In this study, the texture, microstructure and mechanical properties of AZ31 Mg sheets has been investigated during the symmetrical rolling procedure and the asymmetric rolling procedures of different roll speeds with different roll diameters. Texture of Mg alloy sheets were evaluated by using X-ray diffraction and ODFs were calculated using ADC method. The major texture of rolled specimens can be expressed by ND//(0001) fiber texture. The major fiber texture changed according to the rolling processes and such a slight difference of texture changes the formability of sheets. The mechanical properties were enhanced during asymmetrical rolling.