Influences of Rolling Conditions on Texture and Formability of Magnesium Alloy Sheets

2010 ◽  
Vol 638-642 ◽  
pp. 1536-1540 ◽  
Author(s):  
Xin Sheng Huang ◽  
Kazutaka Suzuki ◽  
Akira Watazu ◽  
Ichinori Shigematsu ◽  
Naobumi Saito
Keyword(s):  
Magnesium Alloy ◽  
Rotation Speed ◽  
Rolling Direction ◽  
Rolling Temperature ◽  
Speed Ratio ◽  
Basal Texture ◽  
Homogeneous Microstructure ◽  
Texture Intensity ◽  
Differential Speed Rolling ◽  
Stretch Formability

The AZ61 magnesium alloy was subjected to the differential speed rolling at different rolling conditions including reduction per pass, rotation speed ratio and rolling temperature, and the influences of the rolling conditions on microstructure, texture, mechanical properties and formability of the as-rolled sheets were investigated. Increasing the reduction per pass results in a more homogeneous microstructure and a relatively weaker basal texture. With increasing the rotation speed ratio, the inclination angle of basal pole toward the rolling direction increases and the stretch formability enhances correspondingly. Increasing the rolling temperature has an effect on weakening the basal texture intensity and leads to the enhancement of stretch formability.

Influences of Rolling Conditions on Texture and Mechanical Properties of AZ31 Magnesium Alloy Processed by Differential Speed Rolling

2007 ◽  
Vol 561-565 ◽  
pp. 287-290
Author(s):  
Kazutaka Suzuki ◽  
Xin Sheng Huang ◽  
Akira Watazu ◽  
Ichinori Shigematsu ◽  
Naobumi Saito
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Rolling Direction ◽  
Rolling Temperature ◽  
Az31 Magnesium Alloy ◽  
Speed Ratio ◽  
Shear Direction ◽  
Differential Speed Rolling ◽  
Press Formability ◽  
Differential Speed

It was reported that the cold and warm press formability of the magnesium alloy was improved by the application of a differential speed rolling (DSR). However, it can be considered that the microstructure and the texture of the DSR processed sheets greatly change with the rolling conditions. In this study, commercial AZ31B magnesium alloy extrusions were processed by DSR at a differential speed ratio of 1.167 and a reduction per pass of 10% or less, and the effects of the rolling temperature, the number of rolling passes and reversal of the rolling direction on texture and mechanical properties were examined. As a result, it was found that the optimal rolling temperature in terms of the workability and formability of the material was 573 K. And the elongation and formability were maximal in sheets processed by 4–6 passes of DSR. Moreover, reversing the shear direction made the microstructure more homogeneous and finer than unidirectional shear, and improved the mechanical properties and formability. This improvement was greater in samples where the shear direction was reversed once in the middle than where it was reversed for each pass.

scholarly journals Critical Rolling Process Parameters for Dynamic Recrystallization Behavior of AZ31 Magnesium Alloy Sheets

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2019
Author(s):  
Wenke Wang ◽  
Qing Miao ◽  
Xuemin Chen ◽  
Yang Yu ◽  
Wencong Zhang ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Dynamic Recrystallization ◽  
Process Parameters ◽  
Rolling Direction ◽  
Rolling Process ◽  
Alloy Sheet ◽  
Rolling Temperature ◽  
Az31 Magnesium Alloy ◽  
Texture Intensity ◽  
C 30

In this work, the influence of various rolling temperatures and thickness reductions on the dynamic recrystallization (DRX) behavior of AZ31 magnesium alloy sheets was investigated. Meanwhile, the texture variation controlled by DRX behavior was analyzed. Results suggested that, with the help of DRX behavior, reasonable matching of rolling temperature and thickness reduction could effectively refine the grain size and improve the microstructure homogeneity. Using the grain refinement and microstructure homogeneity as the reference, the critical rolling process parameters were 400 °C—30%, 300 °C—30%, and 250 °C—40% in the present work. In terms of basal texture variation, the occurrence of twins produced the largest maximum texture intensity. However, for the sheets with DRX behavior, the maximum texture intensity decreased sharply, but would steadily increase with the growth of DRXed grain. Additionally, for DRXed grains, the <11-20>//RD (RD: rolling direction) grains would gradually annex the <10-10>//RD grains with the growth of DRXed grains, which finally made their texture component become the dominant texture state. However, when the deformation continued, the <10-10> in DRXed grains would rotate toward the RD again. Weighted by the fracture elongation of AZ31 magnesium alloy sheet, the critical thickness reductions were 30–40% under the rolling temperature of 400 °C.

scholarly journals Microstructure, Texture and Mechanical Properties of Mg-6Sn Alloy Processed by Differential Speed Rolling

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 83
Author(s):  
Kamil Majchrowicz ◽  
Paweł Jóźwik ◽  
Witold Chromiński ◽  
Bogusława Adamczyk-Cieślak ◽  
Zbigniew Pakieła
Keyword(s):  
Mechanical Properties ◽  
Mechanical Performance ◽  
Rolling Direction ◽  
Speed Ratio ◽  
Basal Texture ◽  
Electron Backscattered Diffraction ◽  
Normal Anisotropy ◽  
Average Grain Size ◽  
Differential Speed Rolling ◽  
Differential Speed

The effect of shear deformation introduced by differential speed rolling (DSR) on the microstructure, texture and mechanical properties of Mg-6Sn alloy was investigated. Mg-6Sn sheets were obtained by DSR at speed ratio between upper and lower rolls of R = 1, 1.25, 2 and 3 (R = 1 refers to symmetric rolling). The microstructural and textural changes were investigated by electron backscattered diffraction (EBSD) and XRD, while the mechanical performance was evaluated based on tensile tests and calculated Lankford parameters. DSR resulted in the pronounced grain refinement of Mg-6Sn sheets and spreading of basal texture as compared to conventionally rolled one. The average grain size and basal texture intensity gradually decreased with increasing speed ratio. The basal poles splitting to transverse direction (TD) or rolling direction (RD) was observed for all Mg-6Sn sheets. For the as-rolled sheets, YS and UTS increased with increasing speed ratio, but a significant anisotropy of strength and ductility between RD and TD has been observed. After annealing at 300 °C, Mg-6Sn sheets became more homogeneous, and the elongation to failure was increased with higher speed ratios. Moreover, the annealed Mg-6Sn sheets were characterized by a very low normal anisotropy (0.91–1.16), which is normally not achieved for the most common Mg-Al-Zn alloys.

Texture of AZ31 Magnesium Alloy Sheet Heavily Rolled by High Speed Warm Rolling

2007 ◽  
Vol 539-543 ◽  
pp. 3359-3364 ◽  
Author(s):  
Tetsuo Sakai ◽  
Hiroshi Utsunomiya ◽  
H. Koh ◽  
S. Minamiguchi
Keyword(s):  
Magnesium Alloy ◽  
High Speed ◽  
Room Temperature ◽  
Alloy Sheet ◽  
Rolling Temperature ◽  
Az31 Magnesium Alloy ◽  
Basal Texture ◽  
Double Peak ◽  
Magnesium Alloy Sheet ◽  
Az31 Magnesium Alloy Sheet

Magnesium alloy sheets had to be rolled at elevated temperature to avoid cracking. The poor workability of magnesium alloy is ascribed to its hcp crystallography and insufficient activation of independent slip systems. Present authors have succeeded in 1-pass heavy rolling of AZ31 magnesium alloy sheet below 473K by raising rolling speed above 1000m/min. Heavy reduction larger than 60% can be applied by 1-pass high speed rolling even at room temperature. The improvement of workability at lower rolling temperature is due to temperature rise by plastic working. The texture of heavily rolled AZ31 magnesium alloy sheet is investigated in the present study. The texture of sheets rolled 60% at room temperature was <0001>//ND basal texture. At the rolling temperature above 373K, the peak of (0001) pole tilted ±10-15 deg toward RD direction around TD axisto form a double peak texture. The texture varied through thickness. At the surface, the (0001) peak tilted ±10-15 deg toward TD direction around RD axis to form a TD-split double peak texture. The direction of (0001) peak splitting rotated 90 deg from the surface to the center of thickness. Heavily rolled magnesium alloy sheets have non-basal texture. The sheets having non-basal texture are expected to show better ductility than sheets with basal texture.

Effects of manganese addition on microstructure and press formability of hot-rolled Mg–Al–Zn alloy sheets

2008 ◽  
Vol 23 (11) ◽  
pp. 3029-3039 ◽  
Author(s):  
Xinsheng Huang ◽  
Kazutaka Suzuki ◽  
Akira Watazu ◽  
Ichinori Shigematsu ◽  
Naobumi Saito
Keyword(s):  
Az31 Alloy ◽  
Solubility Limit ◽  
Solid Solubility Limit ◽  
Homogeneous Microstructure ◽  
Texture Intensity ◽  
Differential Speed Rolling ◽  
Hot Rolled ◽  
Mn Additions ◽  
Zn Alloy ◽  
Differential Speed

Differential speed rolling (DSR) has been carried out on AZ31 alloys with Mn additions of 0 to 0.6 wt% for investigating the effects of Mn on microstructure, texture, mechanical properties, and formability. The Al–Mn compounds were formed in the sample with a Mn addition of only 0.2 wt% because of its low solid-solubility limit. There were tiny differences among the DSR-processed AZ31 alloys with different Mn contents, while the AZ31 alloy without Mn addition exhibited a more homogeneous microstructure, a weaker basal texture intensity, and a much superior formability together with a larger likelihood of grain growth during annealing. The Mn dissolving in αMg matrix exerted a far stronger influence on the resulting properties compared with those existing in form of the Al–Mn compounds. The Mn solute atoms induced an increase in c/a ratio, which may suppress activity of nonbasal slips and in turn degrade the deformation capability.

scholarly journals Effect of Cyclic Expansion-Extrusion Process on Microstructure, Deformation and Dynamic Recrystallization Mechanisms, and Texture Evolution of AZ80 Magnesium Alloy

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Yong Xue ◽  
Shuaishuai Chen ◽  
Haijun Liu ◽  
Zhimin Zhang ◽  
Luying Ren ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Dynamic Recrystallization ◽  
Grain Refinement ◽  
Texture Evolution ◽  
Extrusion Process ◽  
Basal Texture ◽  
Continuous Dynamic Recrystallization ◽  
Distributed Structure ◽  
Texture Intensity ◽  
Az80 Magnesium Alloy

The microstructure, deformation mechanisms, dynamic recrystallization (DRX) behavior, and texture evolution of AZ80 magnesium alloy were investigated by three-pass cyclic expansion-extrusion (CEE) tests. Optical microscopy (OM), electron back-scattered diffraction (EBSD), and X-ray diffraction (XRD) were employed to study microstructure, grain orientation, DRX mechanism, and texture evolution. The results show that the grain sizes decrease continuously with the increase of CEE pass. The grain refinement effect of the first pass is the most remarkable, and there appear a large number of twins. After three-pass CEE, a well-distributed structure with fine equiaxed grains is obtained. With the increase of CEE pass, the deformation mechanism changes from twinning to slipping and the DRX mechanism changes mainly from twinning-induced dynamic recrystallization (TDRX) to rotation dynamic recrystallization (RDRX) and then to continuous dynamic recrystallization (CDRX). The grain misorientation between the new grains and matrix grains deceases gradually, and a relatively small angle misorientation is obtained after three-pass CEE. Grain misorientations of the first two passes are attributed to TDRX and RDRX behaviors, respectively. The grain refinement changes the deformation and DRX mechanisms of CEE process, which leads the (0002) basal texture intensity first decrease and then increase suddenly. Eventually, the extremely strong basal texture is formed after three-pass CEE.

Rolling Temperature and Subsequent Annealing on Microstructure, Texture and Mechanical Properties of Consecutive Rolled Mg-2.0Zn-0.8Gd Alloy

2013 ◽  
Vol 747-748 ◽  
pp. 369-376 ◽  
Author(s):  
Hong Yan ◽  
Rong Shi Chen ◽  
En Hou Han
Keyword(s):  
Mechanical Properties ◽  
Dynamic Recrystallization ◽  
Transverse Direction ◽  
Rolling Direction ◽  
Annealing Process ◽  
Normal Direction ◽  
Rolling Temperature ◽  
Rolled Sheet ◽  
Basal Texture ◽  
Different Temperatures

Mg-2.0Zn-0.8Gd (wt. %) alloy was rolled consecutively at different temperatures. The influence of rolling temperature and annealing process on the microstructure, texture and mechanical properties of the sheet were investigated. A deformation microstructure consisting of many intersected twins and a few dynamic recrystallization grains, and a basal texture with basal poles tilting about ± 10-15° from the normal direction towards the rolling direction were observed in the as-rolled sheet after 4 consecutive rolling processes. Static recrystallizaiton took place in the sheet after annealed above 300 °C. The annealed sheet exhibited a uniform microstructure and a non-basal texture with basal poles tilting about ± 38-43° from the normal direction towards the transverse direction. The annealed sheets exhibited higher ductility about 32% along the rolling direction and 40% along the transverse direction comparing with the as-rolled sheets. The static recrystallization during annealing process was helpful to modify the texture as well as the dynamic recrystallization during rolling in the RE-containing alloys.

scholarly journals Statistical Analysis on Static Recrystallization Texture Evolution in Cold-Rolled AZ31 Magnesium Alloy Sheet

2013 ◽  
Vol 19 (S5) ◽  
pp. 21-24 ◽  
Author(s):  
Jun-Ho Park ◽  
Tae-Hong Ahn ◽  
Hyun-Sik Choi ◽  
Jung-Man Chung ◽  
Dong-Ik Kim ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Thermomechanical Processing ◽  
Texture Evolution ◽  
Rolling Direction ◽  
Alloy Sheet ◽  
Basal Texture ◽  
Rolled Sample ◽  
Az31 Magnesium Alloy Sheet ◽  
Cold Rolled ◽  
Grain Orientation Spread

AbstractCast AZ31B-H24 magnesium alloy, comprising Mg with 3.27 wt% Al and 0.96 wt% Zn, was cold rolled and subsequently annealed. Global texture evolutions in the specimens were observed by X-ray diffractometry after the thermomechanical processing. Image-based microstructure and texture for the deformed, recrystallized, and grown grains were observed by electron backscattered diffractometry. Recrystallized grains could be distinguished from deformed ones by analyzing grain orientation spread. Split basal texture of ca. ±10–15° in the rolling direction was observed in the cold-rolled sample. Recrystallized grains had widely spread basal poles at nucleation stage; strong {0001} basal texture developed with grain growth during annealing.

Microstructure and Texture Control of Al-Mg Alloy Sheets by Differential Speed Rolling

2005 ◽  
Vol 495-497 ◽  
pp. 597-602 ◽  
Author(s):  
Tetsuo Sakai ◽  
K. Yoneda ◽  
S. Osugi
Keyword(s):  
Shear Strain ◽  
Shear Deformation ◽  
Rolling Direction ◽  
Deformation Texture ◽  
Speed Ratio ◽  
Roll Speed ◽  
Shear Texture ◽  
Differential Speed Rolling ◽  
R Value ◽  
Differential Speed

Large shear deformation was successfully introduced in 5182 aluminum alloy sheets by 2-pass differential speed warm rolling under a high friction condition. The roll speed ratio was varied from 1.0 to 2.0. When the roll speed ratio was smaller than 1.4, shear strain increased near the surface, but the strain decreased to zero at the mid-thickness. At a roll speed ratio larger than 1.4, shear strain was introduced even at the mid-thickness, and it increased near the surface. Thus the shear strain increased with the roll speed ratio. After 2-pass differential speed rolling, a large shear strain prevailed throughout the thickness. The rolling direction of the second pass was so selected that the direction of shear deformation introduced in the second pass was similar to (unidirectional shear rolling) or opposite (reverse shear rolling) that in the first pass. A shear texture with main components of {111}<110>, {112}<110> and {001}<110> prevailed throughout the thickness, and conventional rolling textures such as {112}<111> or {123}<634> orientation were not detected in any part of thickness. The rolling direction of the second pass had little effect on the deformation texture. After recrystallization annealing, the shear texture components were retained. The intensity of the shear texture components after recrystallization was almost similar to the deformation texture. The r-value of the annealed sheet was slightly increased and the planar anisotropy of the r-value was decreased by differential speed rolling. Differential speed rolling, by which shear deformation can be introduced throughout the thickness, was thus shown to be a promising process for improving the physical and mechanical properties of rolled and annealed aluminum alloy sheets by texture control.

Effect of Pass Thickness Reduction on Microstructure and Formability in AZ31 Magnesium Produced by Differential Speed Rolling

2012 ◽  
Vol 152-154 ◽  
pp. 18-23
Author(s):  
Wei Jun Xia ◽  
Ling Liu ◽  
Fu Quan Zhang ◽  
Cong Chang Xu
Keyword(s):  
Thickness Reduction ◽  
Speed Ratio ◽  
Strain Hardening Exponent ◽  
Anisotropy Ratio ◽  
Basal Texture ◽  
Deformation Bands ◽  
Normal Anisotropy ◽  
Low Pass ◽  
Differential Speed Rolling ◽  
Differential Speed

AZ31 magnesium alloy sheets were prepared by multi-pass differential speed rolling (DSR) with small mismatch roll speed ratio. Effect of pass thickness reduction on microstructure, texture and formability at room temperature were investigated. The results showed that the low pass thickness reduction DSR is effective to improve the formability by refining the grain size and weakening the basal texture, which is characterized by the increasing of strain hardening exponent (n value) and elongation as soon as decreasing of yielding ratio and normal anisotropy ratio (r value). With the increasing of pass thickness reduction, more effective grain refinement is achieved due to the forming of deformation bands. While the ability of forming the title basal texture is weakened and the formability is reduced.

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