Microstructure and Texture Dependence of Asymmetric Rolled AZ31 Mg Alloy

2007 ◽  
Vol 345-346 ◽  
pp. 77-80
Author(s):  
Jae Seol Lee ◽  
Hyeon Taek Son ◽  
Young Kyun Kim ◽  
Ki Yong Lee ◽  
Hyoung Mo Kim ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Transverse Direction ◽  
Rolling Direction ◽  
Rolling Process ◽  
Fiber Texture ◽  
The Other ◽  
Asymmetric Rolling ◽  
Rolled Sample ◽  
Deformation Twins ◽  
Az31 Mg Alloy

In this study, we try to investigate the asymmetric rolling process affects microstructure, texture and formability of AZ31 Mg sheet. The deformation twins are clearly apparent, small and recrystallized grains are visible along some grain boundary and twinned regions in the as-rolled both samples. The symmetrically rolled sample tended to show peak inclined to the rolling direction. On the other hand, the asymmetrically rolled sample tended to show peak slightly inclined to the transverse direction. From the pole figure observation by EBSD, the intensity decrease of basal fiber texture after asymmetric rolling should be attributed to the severe shear strain induced during asymmetric process. The Erichsen value was measured to be 6.5 for asymmetrically rolled sample and 5.2 for symmetrically rolled sample.

Texture Control of Aluminum and Magnesium Alloys by the Symmetric/Asymmetric Combination Rolling Process

2011 ◽  
Vol 702-703 ◽  
pp. 68-75 ◽  
Author(s):  
Hirofumi Inoue
Keyword(s):  
Rolling Direction ◽  
Solution Treatment ◽  
Rolling Process ◽  
Warm Rolling ◽  
Fiber Texture ◽  
Drawing Ratio ◽  
Asymmetric Rolling ◽  
Automotive Body ◽  
Solution Treated ◽  
Aluminum And Magnesium Alloys

In order to develop favorable textures for deep drawing of Al-Mg-Si and Mg-Al-Zn alloys that are promising as automotive body panels, we have adopted the symmetric/asymmetric combination rolling (SACR) process consisting of conventional symmetric rolling and subsequent asymmetric rolling at relatively low reduction. The combination of symmetric cold rolling and asymmetric warm rolling for AA6022 sheets leads to the formation of “TD-rotated β-fiber texture”, resulting in the evolution of {111} recrystallization texture after solution treatment at a high temperature. The SACR processed and solution-treated sheets show a high average r-value with small in-plane anisotropy, and consequently the limiting drawing ratio increases significantly, compared to that of the cold-rolled and solution-treated sheets. In the case of AZ31 magnesium alloy, the SACR process by hot rolling causes the formation of a unique texture, which shows two (0001) poles with tilt angles of 0 and −40 degrees from the normal direction (ND) toward the rolling direction (RD). In addition, subsequent annealing weakens intensity of the double-peak texture, so that the drawability is greatly improved in comparison with that of the conventional warm-rolled sheets with a strong basal texture. At the same time, yield strength decreases to some extent, but the SACR processed and annealed sheets exhibit a good balance of strength and formability due to a mixed texture with basal and tilt components.

scholarly journals Microstructure Characterization and Mechanical Property of Mg/Al Laminated Composite Prepared by the Novel Approach: Corrugated + Flat Rolling (CFR)

Metals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 690 ◽  
Author(s):  
Tao Wang ◽  
Sha Li ◽  
Zhongkai Ren ◽  
Yi Jia ◽  
Wenshi Fu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Rolling Direction ◽  
Laminated Composite ◽  
Rolling Process ◽  
Interfacial Microstructure ◽  
Rolled Sample ◽  
Novel Approach ◽  
Flat Rolling ◽  
Interfacial Intermetallic Compounds

In this paper, Mg/Al laminated composites were successfully prepared at 400 °C by corrugated + flat rolling (CFR) with reduction ratios of 35% and 25% and subsequent annealing treatments were conducted at 200–350 °C for 30 min. A two-dimensional model was established to analyze the strain distribution during the first corrugated rolling process. Simulation results indicated that severe plastic deformation was formed at trough positions, which included more numerous refined grains than in the peak positions. The interfacial microstructure and mechanical property of the flattened composites along the rolling direction (RD) and the transverse direction (TD) were investigated. The results revealed that longitudinal discontinuous and transverse continuous interfacial intermetallic compounds (IMCs) were observed of the flattened as-rolled sample. Spatial distribution was provided for the grain microstructure along the thickness and rolling direction for AZ31B magnesium alloys of the CFR as-rolled composite. Mechanical property results showed that the longitudinal ultimate tensile strength (UTS) and elongation (EL) of the as-rolled sample reached 255 MPa and 4.14%, respectively. The as-rolled UTS along TD reached 325 MPa, about 30% higher than that along the RD. After heat treatment, the anisotropy of mechanical properties remained. The microstructure evolution and mechanical properties were discussed in detail.

Boron and Phosphorus Segregation Behavior at Grain Boundary in a Ti-If Steel after Annealing

2010 ◽  
Vol 152-153 ◽  
pp. 320-325 ◽  
Author(s):  
Xin Li Song ◽  
Ze Xi Yuan ◽  
Juan Jia ◽  
Ping He Li ◽  
Di Wang ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Rolling Direction ◽  
Optical Microscope ◽  
If Steel ◽  
Microstructure Development ◽  
Rolled Sample ◽  
Phosphorus Segregation ◽  
Segregation Behavior ◽  
Cold Roll ◽  
Cold Rolled

The cold roll B-added Ti-IF steel is annealed for different times at 810 oC. The microstructure development is studied by Optical Microscope（OM） and the concentration of boron and phosphorus segregation at grain boundary is measured by Auger electron spectroscopy（AES）. The result shows that the grain of the cold- rolled sample is elongated along the rolling direction and the elongated grains become into equi-axis shape after annealing 60 to 180sec. Boron and phosphorus segregated at gain boundaries. But boron’s concentration at grain boundary is higher than that of phosphorus and increase from 5at.% or so to about 10at% after annealing 150sec, Then boron’s concentration decrease slowly to 8at.% at 240sec. While phosphorus’s concentration increase to the max of 2.5at.% or so at 120sec, then its concentration decrease to 1at.% or so after annealing 240sec.

Effect of Rolling Temperature on the Evolution of Microstructure, Texture, and Mechanical Properties of AZ31 Mg Alloy

2011 ◽  
Vol 702-703 ◽  
pp. 76-79
Author(s):  
No Jin Park ◽  
Sun Hea Hwang
Keyword(s):  
Room Temperature ◽  
Radial Direction ◽  
Rolling Direction ◽  
Fiber Texture ◽  
Slip Systems ◽  
Practical Application ◽  
Az31 Mg Alloy ◽  
Promising Solution ◽  
Full Annealing ◽  
Evolution Of Microstructure

Magnesium alloys have attracted a great deal of attention and have been extensively studied, but there is still a major obstacle to their practical application, namely, their poor formability at room temperature, which basically originates from their insufficient number of slip systems. The development of a microstructure and/or texture that is more conducive to formability is one promising solution that could improve their formability. In the present work, the microstructures, textures, and tensile properties of AZ31 Mg alloys are studied following extrusion and full annealing and rolling at 100 and 300°C. After full annealing, a strong ∥ED fiber texture and a weak + ∥ED fiber texture (c-axes in the radial direction) were developed. After 40% rolling at 100°C, many deformed twins were observed and a relatively weak texture was developed. The basal poles were split and rotated about 20° to the rolling direction (RD). During 60% rolling at 300°C, dynamic recrystallization (DRX) took place and a strong ∥ND fiber texture was developed, and this had an influence on the alloys’ poor formability at room temperature.

Effects of Cross-Rolling on Deformation Texture Evolution in Unalloyed Titanium

2016 ◽  
Vol 879 ◽  
pp. 2014-2019
Author(s):  
Osamu Umezawa ◽  
Norimitsu Koga
Keyword(s):  
Rolling Mill ◽  
Transverse Direction ◽  
Texture Evolution ◽  
True Strain ◽  
Rolling Direction ◽  
Deformation Texture ◽  
Fiber Texture ◽  
Cross Rolling ◽  
Flat Rolling ◽  
The Cross

Unalloyed titanium was rolled with 20% reduction in each pass at 293 K using a cross rolling mill, where the upper and lower rolling axes were skewed each other at an angle of 0, 5 or 10 degree with parallel position. Multi-pass flat-rolling was carried out without any lubricants up to the true strain of 1, where two kinds of rolling directions such as tandem (uni-direction for all passes) and reverse (opposite direction in every passes) were adopted. The strain of specimens was increased proportionally as higher passes regardless of the rolling conditions. The transverse direction (TD) split deformation texture in titanium was generally developed under the cross angle of 0 degree. In the present strips of tandem, a main orientation was identified as (-12-18)[10-10]. In the case of tandem with the cross angle of 5 degree, a fiber texture was developed along (-12-18). That is the reason why a rotation in the rolling direction (RD) was overlapped. In the case of reverse with the cross angle of 5 degree, the main orientation was separated into [10-10] and [2-311] that were corresponded to TD and RD splits, respectively.

Post Creep Microstructures of Ti-6A12Sn4Zrf3Mo Alloy

1977 ◽  
Vol 35 ◽  
pp. 274-275
Author(s):  
S. Fujishiro ◽  
A. W. Sommer
Keyword(s):  
Creep Rate ◽  
Transverse Direction ◽  
Elevated Temperatures ◽  
Rolling Direction ◽  
The Other ◽  
Secondary Creep ◽  
Slip Systems ◽  
Alloy Plate ◽  
Schmid Factor ◽  
Secondary Creep Rate

It has been reported (1,2) that in highly textured titanium alloys the secondary creep rate in the direction normal to major concentration of basal poles at elevated temperatures is much greater than that of the c-direction. This phenomenon can be attributed to two major reasons: the first is that Youngs Modulus in the c-direction is approximately 25% higher than in the a-direc- tion; the second is that if an alpha grain is oriented in the c-direction with respect to the applied stress, the Schmid factor for prismatic planes is zero, and thus the slip on the major slip systems is extremely restricted. In the present study, two sets of creep specimens have been prepared from a highly textured Ti-6A12Sn4Zr6Mo alloy plate; one set is parallel to the rolling direction and the other set is parallel to the long transverse direction (major concentration of c-poles).

Magnetostriction and Crystallographic Texture in Rolled and Annealed Fe-Ga Based Alloys

2005 ◽  
Vol 888 ◽  
Author(s):  
Suok-Min Na ◽  
Alison B. Flatau
Keyword(s):  
Surface Energy ◽  
Grain Boundary ◽  
Crystallographic Texture ◽  
Rolling Direction ◽  
Fiber Texture ◽  
Selective Growth ◽  
Conventional Rolling ◽  
The Ideal

ABSTRACTResults that demonstrate the selective development of {100}<001> preferred texture in polycrystalline Fe81.3Ga18.7 plus B (0.5∼1.0 at.%) and S (∼0.05 at.%) alloys using a conventional rolling and annealing processes are presented in this work. We found that boron improved ductility by enhancing grain boundary cohesion during rolling and sulfur played an important role in controlling the surface energy and formation of the selective growth of {100} grains during annealing. The as-rolled (Fe81.3Ga18.7)+0.5 at.%B+0.005 at.%S sheet had some {100}<011> and near {111}<011> texture corresponding to α-fiber texture parallel to the rolling direction. The near {100}<001> sheet texture was formed in sheet that was annealed at 1200°C for 2h (198 ppm), while the texture of sheet annealed at 1100°C for 4h (165 ppm) was closer to {110}<001>. The maximum observed magnetostriction of 220 ppm was obtained as a result of a double annealed, first at 1000°C for 6h and then at 1200°C for 1h, with the resultant texture closer to the ideal {100}<001> than the less desirable {100}<011>.

{111} Recrystallization Texture Evolution in Al-Mg-Si Alloy Sheets Fabricated by Symmetric/Asymmetric Combined Rolling Process

2014 ◽  
Vol 783-786 ◽  
pp. 33-38 ◽  
Author(s):  
Hirofumi Inoue
Keyword(s):  
Recrystallization Texture ◽  
Texture Evolution ◽  
Solution Treatment ◽  
Rolling Process ◽  
Warm Rolling ◽  
Fiber Texture ◽  
Asymmetric Rolling ◽  
Automotive Body ◽  
High Fraction ◽  
High Reduction

A new rolling process, which combined asymmetric rolling with symmetric rolling, was adopted in age-hardenable 6xxx series Al-Mg-Si alloy promising as automotive body panels in order to develop favorable textures for the deep drawability after solution treatment. Symmetric cold rolling at high reduction and subsequent asymmetric warm rolling at low reduction for AA6022 sheets led to the formation of “TD-rotated β-fiber texture” including moderate {111}<uvw>-oriented components, resulting in noticeable evolution of {111}<110> recrystallization texture during the solution treatment at a high temperature. The results of texture analysis and microstructural observation suggested that the low stored energy after asymmetric warm rolling, the high fraction of high angle boundaries with neighboring deformed matrices and the approximate 40° <111> orientation relationship with deformed matrices would strongly affect the evolution of {111}<110> recrystallization texture.

Microstructure and Mechanical Properties of Al-Li Alloy 2397-T87 Rolled Plate

2014 ◽  
Vol 788 ◽  
pp. 249-257
Author(s):  
Chun Ping Fan ◽  
Zi Qiao Zheng ◽  
Min Jia ◽  
Ji Fa Zhong ◽  
Bin Cheng
Keyword(s):  
Electron Microscopy ◽  
Fracture Toughness ◽  
Transverse Direction ◽  
Subsurface Layer ◽  
Rolling Direction ◽  
Cube Texture ◽  
Fiber Texture ◽  
Rolled Plate ◽  
Short Transverse ◽  
Short Transverse Direction

The microstructure, tensile property and fracture toughness of Al-Li alloy 2397-T87 rolled plate were investigated by optical microscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, tensile and plane-strain fracture toughness tests. The results show that a pronounced texture variation through the plate thickness was found. Near the surface, Goss texture dominated. While in the center of the plate, typical β fiber texture and a scattering of cube texture were observed. And the subsurface layer exhibited a very weak texture. From the center to the subsurface, the fraction of β fiber texture and cube texture decreased. In contrast, the fraction of shear type texture reaching the maximum in subsurface layer increased. The tensile properties in different layers along the thickness direction were inhomogeneous. The strengths near the surface were lower than those in the center. And the through-thickness strength properties variation in the rolling direction was more remarkable than that in the long transverse direction. In the same thickness layer, the fracture toughness and the strengths were anisotropic. The strengths in the rolling direction were higher than those in the long transverse direction and the short transverse direction, and the strengths in the short transverse direction were the lowest. The fracture toughness in L-T orientation was the highest, followed by that in T-L orientation, and the fracture toughness in S-L orientation was the lowest.

Twinning and Twinned Bands Turning During Plastic Deformation in Rolled Mg Alloy AZ31

2007 ◽  
Vol 345-346 ◽  
pp. 717-720 ◽  
Author(s):  
Gao Feng Quan
Keyword(s):  
Plastic Deformation ◽  
Deformation Process ◽  
Transverse Direction ◽  
Rolling Direction ◽  
Rolling Process ◽  
Mg Alloy ◽  
Alloy Az31 ◽  
Az31 Sheet ◽  
Secondary Twinning

It is studied the deformation process by IN SITU surface morphology observation for Mg alloy AZ31 sheet in an SEM. It is found that the deformation starts phenomenologically from twinning process, making out of the first twinning in both intact crystallite grains and existing twinned bands by rolling process, and the secondary twinning in original twinned bands. As the plastic strain increases the twinned bands turn to transverse direction (TD) of the sheet in all three tensile directions: rolling direction (RD), TD and 45° to rolling direction (45). The turning characteristic of grain boundaries were dealt with as well.

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