• Transactions of Materials Processing
• /
• v.9 no.2
• /
• pp.193-202
• /
• 2000

The influence of rolling draughts on the formation of through-thickness textures in aluminum 5000X sheet was investigated by X-ray texture measurements and microstructure observations. In order to intensify the deformation inhomogeneities, cold rolling was performed without lubrication. Applying a large draught gave rise to the formation of the shear texture at the surface, whereas a normal plane strain testure formed at the surface after deformation with a small draught. The orientation density along the $\beta$-fiber orientations which developed in the center layer of the rolled specimen was also dependent on the strain gradients in a roll gap. Upon annealing, the deformed substructure of sample surfaces was transformed into a fine grained recrystallized microsturcture through extended recovery reaction. However, coarse grains developed after the discontinuous recrystallization which gave rise to the development of the Cube-texture.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2007.10a
• /
• pp.87-90
• /
• 2007

The evolution of texture and microstructure was tracked for a number of differently cold rolled aluminum sheet and through-thickness layers which were differentiated by different strain states upon preceding deformation. The results substantiate a correlation of deformation texture with the amount of shear applied during cold rolling.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2003.05a
• /
• pp.92-95
• /
• 2003

Asymmetric rolling of AA1050 Al alloy sheets was performed to obtain the shear textures for improving the deep drawability and the grain refinement. The effect of roll velocity ratio on the texture and the grain refinement of 50％ asymmetrically rolled sheets was studied. The textures of the asymmetrically rolled sheets after annealing at 400$^{\circ}C$ for 1 h was also investigated.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 1997.10a
• /
• pp.198-201
• /
• 1997

Aluminum alloy sheets are considered as one of the high potential substitutes for steel sheets considering weight reduction of automobiles. However, aluminum alloy sheets have drawbacks in higher prices and inferior formability compared to steel sheets. In order to achieve good deep drawability, it is imperative to obtain well developed {111} texture which gives rise to higher plastic strain ratio. It is difficult to obtain this texture from conventional rolling and annealing processes. Therefore, an unconventional rolling process which enhances shear deformation has been experimentally studied to obtain the well developed {111} texture, which in turn gives rise to a substantial increase in plastic strain ratio.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 1997.10a
• /
• pp.210-215
• /
• 1997

The development of rolling texture is dependent on the various rolling condition. And the geometry of rolling gab and the friction between rolls and rolled material mainly affect the type and sharpness of texture inhomogeneity through thickness. In order to follow the effect of geometry and friction various strain/pass and lubrication condition were applied during cold rolling. In this investigation various strain/pass and lubrication were applied during cold rolling in order to follow the effect rolling gap geometry and friction. More high 1/h was, more weak the ${\beta}$-fiber was and in the condition of l/h > 5 {001}<110> shear texture developed. In adition, rolling without lubrication enhanced the shear texture.

• Geomechanics and Engineering
• /
• v.12 no.2
• /
• pp.211-221
• /
• 2017

A laboratory investigation into crude oil contaminated sand-concrete interface behavior is performed. The interface tests were carried out through a direct shear apparatus. Pure sand and sand-bentonite mixture with different crude oil contents and three concrete surfaces of different textures (smooth, semi-rough, and rough) were examined. The experimental results showed that the concrete surface texture is an effective factor in soil-concrete interface shear strength. The interface shear strength of the rough concrete surface was found higher than smooth and semi-rough concrete surfaces. In addition to the texture, the normal stress and the crude oil content also play important roles in interface shear strength. Moreover, the friction angle decreases with increasing crude oil content due to increase of oil concentration in soil and it increases with increasing interface roughness.

• Korean Journal of Metals and Materials
• /
• v.56 no.12
• /
• pp.861-869
• /
• 2018

To determine the origin of the inhomogeneous microstructure and texture observed in drawn and annealed high purity copper wires, two kinds of drawing process conditions and their influence was investigated. The regular condition, based on a symmetric die, and a condition designed intentionally to produce an inhomogeneous shear deformation using an asymmetric die were employed. The difference in intensity of <111>-<100> distributed texture between the two wires confirmed that the wire drawn under the asymmetric die condition experienced a higher amount of shear deformation. The extensive shear strain in the wire drawn under the asymmetric die condition gave rise to inhomogeneous primary and secondary recrystallization behavior. After annealing at $200^{\circ}C$, grains with <100> texture, which were larger than the surrounding recrystallized grains, were extensively present on one half circle of the wire drawn under the asymmetric die condition, while larger grains with <100> were sparsely observed around the middle region of the wire drawn under the regular condition. Interestingly, the area where the larger grains with <100> texture existed was identical to the area where the high shear strain occurred during drawing in both wires. During annealing at $400^{\circ}C$, grains with <112> texture started to grow abnormally at the center of both wires as a result of secondary recrystallization. After annealing at $900^{\circ}C$ grains with <112> due to secondary recrystallization occupied the entire region of the wire drawn under the regular condition. On the other hand, in the wire drawn under the asymmetric die condition and then annealed at $900^{\circ}C$, the <100> oriented grains as a result of the normal grain growth of the larger <100> grains which were observed after annealing at $200^{\circ}C$, coexisted with the abnormally grown <112> grains. These results indicate that dynamic recrystallization induced by the shear strain during drawing plays an important role in the inhomogeneity of the microstructure and texture of wires after annealing.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2003.10a
• /
• pp.176-178
• /
• 2003

Strip samples of AA 3103 were deformed by Continuous confined strip shearing (CCSS). The CCSS process was designed to provide a repeated shear deformation in metallic sheet materials. CCSS led to the formation of characteristic shear textures comprising a pronounced｛111｝＜uvw＞ orientations. The intensity of the deformation texture hardly increased with increasing number of CCSS passes. EBSD equipped in a FESEM with a high beam current revealed the formation of fine grains even after annealing for the recrystallization.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2003.10a
• /
• pp.132-135
• /
• 2003

Asymmetric rolling, in which the ratio of the rotation rates of the upper and lower rolls was 2, has been used to introduce an intense plastic shear strain for the purpose of grain refinement and developing shear deformation textures through the sheet thickness to improve the strength and plastic strain ratio of AA1050 aluminum alloy sheets. The alloy sheets were rolled at room temperature without lubrication. The textures and microstructures of the sheets were investigated by x-ray diffraction and electron back-scattered diffraction (EBSD) analyses with emphasis on effects of combinations of rot ling directions.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 1997.03a
• /
• pp.294-297
• /
• 1997

Two kinds of thermo-mechanical treatments(TMT) were applied to two AA3104 alloys. Tensile test, cupping and mesurement were conducted. Height and angular positions of earings in the drawn cups were explained by ODF on the contents of alloying elements. The tensile strengths measured in RD+45$^{\circ}$direction were generally lower than those measured in RD and TD directions. The textures of the experimental alloys were determined as shear texture {100}<011> and Cube texture {100}<001> by ODF's. Some optimum ratio of shear texture {100}<011> and Cube texture {100}<001> for reducing earings was found.