An OIM Analysis on the Deformation Mechanism in Hot Compressed AZ31 Magnesium Alloy

2005 ◽  
Vol 488-489 ◽  
pp. 633-636 ◽  
Author(s):  
Li Meng ◽  
Ping Yang ◽  
Zude Zhao ◽  
Wei Min Mao
Keyword(s):  
Magnesium Alloy ◽  
Az31 Magnesium Alloy ◽  
Deformation Condition ◽  
Basal Texture ◽  
Slip Mechanism ◽  
Plastic Slip ◽  
Pyramidal Slip ◽  
Orientation Mapping ◽  
Ebsd Technique ◽  
Deformation Strain Rate

Orientation mapping based on EBSD technique was applied to analyze the rules of orientation evolution of grains in AZ31 magnesium alloy. Results show that not only under deformation strain rate of 1×10-2s-1, but under 4×10-4s-1(the superplastic deformation condition), grains in all samples with initial textures rotate gradually to near basal orientation ({0002} || compression plane) at different ways, and basal texture becomes stronger with increasing strain, which indicates plastic slip plays an important role during hot deformation. Otherwise, no evident non-basal pyramidal slip of <a+c> as some studies mentioned was observed in the sample with the initial basal texture, and the basal orientation is kept unchanged during the deformation process, which suggests that basal slip is the uppermost plastic slip mechanism in this sample. In addition, the phenomenon of viscous laminar flow was observed in the sample with initial basal texture.

Effects of Texture on the Fracture Mechanism of AZ31 Magnesium Alloy under Dynamic Impact

2014 ◽  
Vol 598 ◽  
pp. 98-101
Author(s):  
Gang Wan ◽  
Bao Lin Wu
Keyword(s):  
Magnesium Alloy ◽  
Basal Slip ◽  
Az31 Magnesium Alloy ◽  
Prismatic Slip ◽  
Shearing Stress ◽  
Basal Texture ◽  
Dynamic Impact ◽  
Pyramidal Slip ◽  
Schmid Factor ◽  
Deformation Modes

the hot extruded AZ31 magnesium alloy which has basal texture was impacted along different direction and different fracture mode appeared. Under different impacted direction, the basal slip, prismatic slip, pyramidal slip, compression twin and tension twin have different critical resolved shearing stress (CRSS) and Schmid factor. Then different deformation modes were activated and resulted to different fracture modes.

Orientational Analysis on Static Recrystallization at Tension Twins in AZ31 Magnesium Alloy

2011 ◽  
Vol 299-300 ◽  
pp. 778-784
Author(s):  
Xiao Li ◽  
Ping Yang ◽  
Li Meng
Keyword(s):  
Magnesium Alloy ◽  
Static Recrystallization ◽  
Volume Fraction ◽  
Early Stage ◽  
Nucleation Site ◽  
Az31 Magnesium Alloy ◽  
Basal Texture ◽  
Promotive Effect ◽  
Ebsd Technique ◽  
Evolution Of Microstructure

The deformation depends on twinning in Mg alloy, and twins will be the dominant recrystallization nucleation site. Tension twinning proceeds much more easily than compression twinning since its volume fraction is much higher than that of compression twins, which may have a promotive effect on the recrystallization to a certain degree. Based on the previous research on the static recrystallization at compression twins, the evolution of microstructure and texture in AZ31 magnesium alloy during its static recystallization at tension twins was further investigated; and the orientational characteristics of new grains formed at tension twins in the early stage of static recrystallization were analyzed by EBSD technique. The results showed that the strong basal texture was retained and weakened with no new texture component being detected during annealing. New grains were observed to nucleate preferentially at the intersections of tension twin variants or the intersection between tension twins and compression twins. Their orientations are relatively random and are strongly scattered from those of original tension twins or compression twins. A comparison of the recrystallization at tension twins and compression twins was further made.

scholarly journals ANALYSIS OF DEFORMATION PROCESSES OF MAGNESIUM ALLOY AT ELEVATED TEMPERATURES BY ORIENTATION MAPPING

2011 ◽  
Vol 23 (1) ◽  
pp. 53 ◽  
Author(s):  
Ping Yang ◽  
Li Meng ◽  
Yisong Hu ◽  
Zude Zhao ◽  
Xueping Ren
Keyword(s):  
Magnesium Alloy ◽  
Elevated Temperatures ◽  
Plastic Slip ◽  
Rotation Axes ◽  
Orientation Mapping ◽  
Back Scattering ◽  
Deformation Processes ◽  
Relationship Of ◽  
The Relationship

Orientation mapping based on electron back scattering diffraction technique was applied to reveal the distributions of disorientations and rotation axes of grains caused by plastic slip and twinning during channel die compression in magnesium alloy ZA31. In addition, the orientations of dynamically recrystallized grains and deformed grains were separated and compared with respect to their initial textures. The relationship of strain and {1012} twin amount was determined quantitatively by referring to twin orientations. The reasons leading to the observed phenomena are analyzed and discussed.

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.

Relative Activities of Deformation Modes in AZ31 Magnesium Alloy Predicted by Mesoscopic Crystalline Model

2011 ◽  
Vol 399-401 ◽  
pp. 21-25
Author(s):  
De Liang Yin ◽  
Jin Qiang Liu ◽  
Xin Chen
Keyword(s):  
Magnesium Alloy ◽  
Room Temperature ◽  
Az31 Magnesium Alloy ◽  
Plastic Response ◽  
Hardening Behavior ◽  
Pyramidal Slip ◽  
Proposed Model ◽  
Tension And Compression ◽  
Strain Hardening Behavior ◽  
Deformation Modes

A mesoscopic crystalline model was proposed to quantitatively analyze the relative activities of deformation modes involved in the plastic deformation of an AZ31 magnesium alloy at room temperature. The plastic response of a cast AZ31 magnesium alloy with random texture can be well predicted by this model. It is demonstrated that the remarkable difference of relative activities of <c+a> pyramidal slip should be attributed to the different strain hardening behavior in tension and compression. Further TEM micrographs shows the occurrence of <c+a> pyramidal slip in compression, which confirms the validity of the proposed model.

scholarly journals Fabrication of Strong and Ductile AZ31 Magnesium Alloy Using High Strain Rate Multiple Forging in a Wide Temperature Range

Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 729 ◽  
Author(s):  
Yuanzhi Wu ◽  
Bin Deng ◽  
Tuo Ye ◽  
Zhicheng Nie ◽  
Xiao Liu
Keyword(s):  
Magnesium Alloy ◽  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Az31 Alloy ◽  
Az31 Magnesium Alloy ◽  
Basal Texture ◽  
Texture Characteristic ◽  
Temperature Range ◽  
Grain Sizes

High strain rate multiple forging (HSRMF) was successfully carried out on AZ31 magnesium alloy at a temperature range of 250–400 °C, and the microstructure, texture and mechanical properties were examined. Full recrystallized structure developed at a relatively lower strain due to the twining induced dynamic recrystallization (TDRX) mechanism, which is also responsible for the feasibility of HSRMF deformation at relative low temperature. The average grain sizes of the alloys high strain rate multiple forged (HSRMFed) to the accumulated strain of ∑Δε = 1.32 increased from 7.07 to 9.99 μm as the temperature ranged from 250 to 400 °C, i.e., the grain sizes of the HSRMFed alloy were less sensitive to temperature. The weakened basal texture characteristic of titled or double peak achieved was ascribed to the alteration of forging direction. The HSRMFed alloys demonstrated both excellent strength (UTS > 300 MPa) and good ductility (δ > 20%), which resulted from the combined effects of grain refinement and weakened basal texture. Therefore, HSRMF was an efficient technique to produce strong and ductile wrought AZ31 alloy.

Anisotropy of Deformation Behavior of AZ31 Magnesium Alloy Sheets

2011 ◽  
Vol 314-316 ◽  
pp. 1121-1125 ◽  
Author(s):  
Yong Qi Cheng ◽  
Zhen Hua Chen
Keyword(s):  
Magnesium Alloy ◽  
Cleavage Fracture ◽  
Deformation Behavior ◽  
Rolling Direction ◽  
Alloy Sheet ◽  
Az31 Magnesium Alloy ◽  
Basal Texture ◽  
Az31 Magnesium Alloy Sheet ◽  
Shearing Deformation ◽  
Anisotropy Of Deformation

In order to develop magnesium alloy sheets with high formability at room temperature, the anisotropy of deformation behavior of AZ31 magnesium alloy sheets produced by equal channel angular rolling were examined, which were compared with that of the sheets produced by the unidirectional hot rolling. The differences in the deformation behavior of the sheets at the rolling direction (0°), 45° and the transverse direction (90°) were discussed in term of the texture and microstructure. Compared with the as-received specimens, the anisotropy of deformation behavior of AZ31 magnesium alloy sheet produced by equal channel angular rolling was enhanced, which was following with an improved ductility and a large work hardening phenomenon. These could be due to the non-basal texture, which was induced by the continuous shearing deformation during equal channel angular rolling procedure. The fracture mechanism transferred from the cleavage fracture for the unidirectional rolling to the quasi-cleavage fracture for the sheets produced by equal channel angular rolling, which proved that the non-basal texture was in favor of the ductility of magnesium alloy.

scholarly journals Effect of Pass Strain on the Microstructure, Texture and Mechanical Properties of AZ31 Magnesium Alloy Fabricated by High Strain Rate Multiple Forging

Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1000
Author(s):  
Yuanzhi Wu ◽  
Bin Deng ◽  
Tuo Ye ◽  
Wei Liu ◽  
Zhicheng Nie ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Strain Range ◽  
Az31 Magnesium Alloy ◽  
Lamellar Thickness ◽  
Basal Texture ◽  
Accumulated Strain

High strain rate multiple forging (HSRMF) with pass strain ranging from 0.1 to 0.35 was carried out on the AZ31 magnesium alloy, and the microstructure, texture and mechanical properties were examined. The initial grain can be refined through the formation of high density {102} and {101(-)1}-{101(-)2} twins and subsequently twining induced dynamic recrystallization (DRX). The grain refinement of the HSRMFed alloy was affected by the lamellar thickness of the twin. Lower pass strain (Δε = 0.1) during HSRMF leads to the thick twin lamellae and consequently results in coarse DRX grain, meanwhile, an incomplete DRX occurs. While the twin lamellae thickness decreases with increasing pass strain, and a saturate thickness can be achieved with higher pass strain (Δε = 0.16–0.35), which results in the finer DRX structure. Homogeneous DXR structure can be obtained only at a proper accumulated strain (∑Δε = 0.96–1.4) during HSRMF, under lower accumulated strain, the DRX is insufficient, while higher accumulated strain leads to abnormal grain growth. A double peak basal texture was achieved at lower pass strain (Δε = 0.1), which developed into titled basal texture, and the texture intensity increases with the pass strain. HSRMFed alloys with homogeneous fine DRX grain and relatively weak texture show high strength and excellent ductility, therefore, and it is inferred that the optimum pass strain and accumulated strain range are 0.16–0.35 and 0.96–1.4 respectively.

Microstructural Evolution and Mechanical Behavior of AZ31 Magnesium Alloy Sheets with Li Addition

2015 ◽  
Vol 816 ◽  
pp. 399-403
Author(s):  
Qing Shan Yang ◽  
Bin Jiang ◽  
Wei Jiang ◽  
Bo Song ◽  
Su Qing Luo ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Mechanical Behavior ◽  
Room Temperature ◽  
Mechanical Performance ◽  
Texture Evolution ◽  
Tensile Tests ◽  
Az31 Alloy ◽  
Az31 Magnesium Alloy ◽  
Basal Texture ◽  
X Ray Diffraction

AZ31 magnesium alloy and its alloy with 5% lithium were extruded to 1mm in thickness sheets at 380 oC with extrusion ratio of 101. Microstructure evolution and mechanical behavior of the extruded Mg alloy sheets were examined. The microstructure and texture evolution were investigate by electronic backscattered diffraction (EBSD) and X-ray diffraction (XRD). Mechanical performance was carried out by tensile tests at room temperature. In addition, the evolution of neutral layer and microstructure was also examined by V-bending. It was found that Li addition resulted in the strong divergence of the grain orientation. (0002) basal texture of AZ31 alloy sheets with 5% lithium has been weakened. The room temperature ductility of these textural sheets was enhanced owing to the tilted weak basal texture. Moreover, it exhibits superior ductility during V-bending process at room temperature.

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