Effect of Initial Texture on Rollability of Mg-3Al-1Zn Alloy Sheet

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Q. Dai ◽  
W. Lan ◽  
X. Chen
Keyword(s):  
Microstructural Analysis ◽  
Alloy Sheet ◽  
Grain Structure ◽  
Basal Texture ◽  
Hexagonal Close Packed ◽  
Uniform Microstructure ◽  
Az31 Mg Alloy ◽  
Edge Cracks ◽  
Initial Texture ◽  
Anisotropic Deformation

The influence of initial texture on rollability is investigated using cuneal AZ31 Mg alloy sheets. Upon large thickness reduction, the sheet with initial basal texture has many edge cracks, whereas the sheet is crack-free if its normal direction is orthogonal to c-axis of hexagonal close packed (HCP) lattice. Microstructural analysis shows that the former one has heterogeneous grain structure owing to grain-boundary-related recrystallization, and by contrast the later one has a more uniform microstructure for the twin-related recrystallization. The initial nonbasal texture can lead to excellent rollability and anisotropic deformation, based on which a new iterative approach of rolling is proposed, which may achieve large reduction in few passes.

Effect of Clock Rolling on Microstructures and Properties of AZ31 Magnesium Alloy Sheets

2011 ◽  
Vol 686 ◽  
pp. 40-45 ◽  
Author(s):  
Xin Huang ◽  
Guang Jie Huang ◽  
Dong Ping Xiao ◽  
Qing Liu
Keyword(s):  
Mechanical Properties ◽  
Az31 Alloy ◽  
Annealed Sample ◽  
Alloy Sheet ◽  
Basal Texture ◽  
Texture Measurement ◽  
Grain Sizes ◽  
Uniform Microstructure ◽  
Similar Texture ◽  
Anisotropy Of Mechanical Properties

In this paper, the influence of clock rolling（CR）on microstructure and texture as well as the anisotropic properties of AZ31 alloy sheet was systematically studied. Compared to unidirectional rolling（UR）, clock rolling leads to more uniform microstructure in annealed sample. The average grain sizes of the two kinds of sheet are similar. Texture measurement reveals that clock rolling can effectively weaken the intensity of basal texture and generate more symmetrical basal texture. Clock rolled samples exhibit weaker anisotropy of mechanical properties due to its lower basal texture intensities and more symmetrical basal texture in tensile test.

scholarly journals Effect of Multi-Pass Caliber Rolling on Dilute Extruded Mg-Bi-Ca Alloy

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 332
Author(s):  
Shuaiju Meng ◽  
Hui Yu ◽  
Haisheng Han ◽  
Jianhang Feng ◽  
Lixin Huang ◽  
...  
Keyword(s):  
Grain Structure ◽  
High Yield ◽  
Processing Route ◽  
Basal Texture ◽  
High Yield Strength ◽  
Uniform Microstructure ◽  
Significant Strength ◽  
Elongation To Failure ◽  
Novel Processing ◽  
Strength Improvement

A Mg-1.32Bi-0.72Ca (BX11) alloy having bimodal grain structure was successfully prepared by a novel processing route of combining extrusion and three-pass caliber rolling. The first extruded and then caliber-rolled (E-CRed) alloy demonstrates a necklace-like grain structure with ultrafine grains formed around the microscale deformed grains, which is remarkably different from the uniform microstructure of the as-extruded alloy. In addition, the E-CRed BX11 alloy exhibits strong basal texture which is mainly original from the microscale deformed grains. Furthermore, the E-CRed BX11 alloy demonstrates excellent comprehensive mechanical properties, with an ultra-high yield strength of 351 MPa and a good elongation to failure of 13.2%. The significant strength improvement can be mainly attributed to the significant grain refinement and much stronger basal texture compared with the as-extruded sample.

scholarly journals Enhancing the Mechanical Properties of AZ80 Alloy by Combining Extrusion and Three Pass Calibre Rolling

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 249 ◽  
Author(s):  
Shuaiju Meng ◽  
Hui Yu ◽  
Jun Zhou ◽  
Haisheng Han ◽  
Yongyan Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Strength ◽  
Grain Structure ◽  
Processing Route ◽  
Bimodal Microstructure ◽  
Basal Texture ◽  
Micro Scale ◽  
Uniform Microstructure ◽  
Novel Processing ◽  
Az80 Alloy

An AZ80 alloy with ultra-high strength and good ductility has been successfully prepared by a novel processing route of combining extrusion and caliber rolling. The caliber rolled (CRed) AZ80 alloy has a necklace grain structure with ultrafine dynamic recrystallized (DRXed) grains formed around the micro-scale deformed grains, which is remarkably different from the uniform microstructure of as-extruded sample free from caliber rolling. In addition, both the deformed region and the DRXed part in CRed AZ80 alloy exhibit more random basal texture than that of the as-extruded sample. Furthermore, the CRed AZ80 alloy demonstrates an excellent comprehensive mechanical property with the ultimate tensile strength of 446MPa and elongation of 13%, respectively. These good mechanical properties of CRed AZ80 alloy can be attributed to the synthetic effects of necklace bimodal microstructure containing ultra-fine grains, profuse Mg17Al12 precipitates, and the modified texture.

scholarly journals Laser Powder Bed Fusion Processing of Fe-Mn-Al-Ni Shape Memory Alloy—On the Effect of Elevated Platform Temperatures

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 185
Author(s):  
Felix Clemens Ewald ◽  
Florian Brenne ◽  
Tobias Gustmann ◽  
Malte Vollmer ◽  
Philipp Krooß ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Crack Formation ◽  
Microstructural Analysis ◽  
Tensile Load ◽  
Grain Structure ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Cyclic Heat Treatment ◽  
Powder Bed ◽  
Cyclic Heat

In order to overcome constraints related to crack formation during additive processing (laser powder bed fusion, L-BPF) of Fe-Mn-Al-Ni, the potential of high-temperature L-PBF processing was investigated in the present study. The effect of the process parameters on crack formation, grain structure, and phase distribution in the as-built condition, as well as in the course of cyclic heat treatment was examined by microstructural analysis. Optimized processing parameters were applied to fabricate cylindrical samples featuring a crack-free and columnar grained microstructure. In the course of cyclic heat treatment, abnormal grain growth (AGG) sets in, eventually promoting the evolution of a bamboo like microstructure. Testing under tensile load revealed a well-defined stress plateau and reversible strains of up to 4%.

Morphology of Edge Cracks of Rolled Magnesium Alloy Sheet

2014 ◽  
Vol 922 ◽  
pp. 469-474 ◽  
Author(s):  
Sho Manabe ◽  
Hiroshi Utsunomiya ◽  
Tetsuo Sakai ◽  
Ryo Matsumoto
Keyword(s):  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
High Speed ◽  
Heating Temperature ◽  
Thin Sheet ◽  
Contact Length ◽  
Alloy Sheet ◽  
Different Temperatures ◽  
Edge Cracks ◽  
Critical Reduction

Magnesium alloys show low deformability at low temperature because of hcp structure and inactiveness of basal slip. Manufacturing of thin sheet is difficult in industries. Some approaches, such as small-draft multi-pass rolling, intermediate annealing, isothermal rolling and high-speed rolling were proposed to overcome the deformability. However, small edge cracks are still formed on the sheet. In this study, rolling speed of 1000m/min was employed to warm-roll AZ31B magnesium alloy in a single pass at different temperatures. The edge cracks formed after the rolling were classified into three main groups: minor, regular and zigzag edge cracks. ‘Crack contact length’ are introduced to explain the morphology of edge cracks. The results show that the critical reduction for crack initiation depends on the pre-heating temperature. The spacing between edge cracks increases linearly with the crack contact length regardless of roll diameter, speed and reduction. It is suggested that this approach is useful to understand the formation mechanism of edge cracks and to evaluate the rollability of magnesium 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.

Numerical Investigation of the Origin of Anomalous Tensile Twinning in Magnesium Alloys

2019 ◽  
Vol 141 (3) ◽  
Author(s):  
K. V. Vaishakh ◽  
N. Subrahmanya Prasad ◽  
R. Narasimhan
Keyword(s):  
Magnesium Alloys ◽  
Basal Slip ◽  
Rolling Direction ◽  
Local Stress ◽  
Tensile Loading ◽  
Normal Direction ◽  
Basal Texture ◽  
Loading Direction ◽  
Az31 Mg Alloy ◽  
Catalytic Role

It has been observed that tension twins (TTs) are triggered in rolled polycrystalline magnesium alloys under tensile loading applied along the rolling direction (RD) or the transverse direction. This is surprising because these alloys have a near-basal texture, and TTs would therefore cause extension (instead of contraction) along the normal direction. In this work, the origin of these anomalous TTs is first examined by performing crystal plasticity-based finite element simulations using model textures, wherein the c-axis in one grain is systematically tilted toward the loading direction (RD), with the other grains maintained in ideal basal orientation. It is shown that strong basal slip is triggered in the former, which through its effect on the local stress distribution plays a catalytic role in activating TTs. The above behavior is also observed in a simulation performed with an actual texture pertaining to a rolled AZ31 Mg alloy. Most importantly, when basal slip is suppressed, evolution of TTs is found to be very much retarded. The present results corroborate well with experimental observations.

High Temperature Deformation Behavior of Strip-Cast AZ31 Mg Alloy

2006 ◽  
Vol 15-17 ◽  
pp. 461-466
Author(s):  
B.H. Lee ◽  
Won Kyu Bang ◽  
Sang Ho Ahn ◽  
Chong Soo Lee
Keyword(s):  
High Temperature ◽  
Processing Map ◽  
Microstructural Analysis ◽  
Processing Condition ◽  
Mg Alloy ◽  
Temperature Deformation ◽  
Maximum Efficiency ◽  
Optimum Processing ◽  
Az31 Mg Alloy ◽  
Strip Cast

In this study, optimum processing conditions for strip-cast AZ31 Mg alloy was investigated on the basis of processing map and microstructural analysis. To obtain the processing map, isothermal compression tests were carried out to a strain of 0.5 at temperatures of 200 ∼ 400°C with the strain rates of 0.01 ∼ 10s-1. It was found that maximum efficiency indicating the optimum processing condition occurred at 300°C and 10s-1. The possible deformation mechanisms operating at high temperature was also discussed.

Prediction of edge cracks and plastic-damage analysis of Mg alloy sheet in rolling

2011 ◽  
Vol 21 (5) ◽  
pp. 1112-1117 ◽  
Author(s):  
Ding-fei ZHANG ◽  
Qing-wei DAI ◽  
Lin FANG ◽  
Xing-xing XU
Keyword(s):  
Alloy Sheet ◽  
Mg Alloy ◽  
Damage Analysis ◽  
Plastic Damage ◽  
Edge Cracks
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