scholarly journals A Further Improvement in the Room-Temperature Formability of Magnesium Alloy Sheets by Pre-Stretching

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2633 ◽  
Author(s):  
Umer Masood Chaudry ◽  
Kotiba Hamad ◽  
Jung-Gu Kim
Keyword(s):  
Magnesium Alloy ◽  
Strain Hardening ◽  
Basal Slip ◽  
Room Temperature ◽  
Slip Systems ◽  
Basal Texture ◽  
Homogeneous Microstructure ◽  
Enhanced Strain ◽  
Grain Misorientation

Pre-stretching experiments were carried out on AZ31–0.5Ca magnesium alloy to alter the microstructure and texture for enhancing room-temperature formability. Compared to as-received alloy, the formability of a 5%-stretched sample was improved by 15%. This was attributed to enhanced strain hardening capability related to the weakening of basal texture and less homogeneous microstructure. In addition, in-grain misorientation axis analysis performed on the samples (as-received and stretched) also confirmed the higher activity of the non-basal slip systems in the 5%-stretched sample.

scholarly journals Ca-induced Plasticity in Magnesium Alloy: EBSD Measurements and VPSC Calculations

Crystals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 67 ◽  
Author(s):  
Umer Masood Chaudry ◽  
Kotiba Hamad ◽  
Jung-Gu Kim
Keyword(s):  
Shear Stress ◽  
Magnesium Alloy ◽  
Slip System ◽  
Basal Slip ◽  
Room Temperature ◽  
Prismatic Slip ◽  
Slip Systems ◽  
Electron Backscattered Diffraction ◽  
Self Consistent ◽  
Critical Resolved Shear Stress

In the present work, Ca-induced plasticity of AZ31 magnesium alloy was studied using electron backscattered diffraction (EBSD) measurements supported by viscoplastic self-consistent (VPSC) calculations. For this purpose, alloy samples were stretched to various strains (5%, 10%, and 15%) at room temperature and a strain rate of 10−3 s−1. The EBSD measurements showed a higher activity of non-basal slip system (prismatic slip) as compared to that of tension twins. The VPSC confirmed the EBSD results, where it was found that the critical resolved shear stress of the various slip systems and their corresponding activities changed during the stretching of the alloy samples.

Plastic Deformation of Mo(Si,Al)2 Single Crystals with the C40 Structure

1996 ◽  
Vol 460 ◽  
Author(s):  
M. Moriwaki ◽  
K. Ito ◽  
H. Inui ◽  
M. Yamaguchi
Keyword(s):  
Single Crystals ◽  
Deformation Behavior ◽  
Basal Slip ◽  
Room Temperature ◽  
Slip Systems ◽  
Temperature Range ◽  
Al Content ◽  
Partial Dislocations ◽  
Increasing Temperature ◽  
Critical Resolved Shear Stress

ABSTRACTThe deformation behavior of single crystals of Mo(Si,Al)2 with the C40 structure has been studied as a function of crystal orientation and Al content in the temperature range from room temperature to 1500°C in compression. Plastic flow is possible only above 1100°C for orientations where slip along <1120> on (0001) is operative and no other slip systems are observed over whole temperature range investigated. The critical resolved shear stress for basal slip decreases rapidly with increasing temperature and the Schmid law is valid. Basal slip appears to occur through a synchroshear mechanism, in which a-dislocations (b=1/3<1120>) dissociate into two synchro-partial dislocations with the identical Burgers vector(b*1/6<1120>) and each synchro-partial further dissociates into two partials on two adjacent planes.

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.

Study on Compression Behaviour of AZ31 Magnesium Alloy at Room-Temperature

2012 ◽  
Vol 476-478 ◽  
pp. 1960-1964
Author(s):  
Jia Le Sun ◽  
Rui Chun Li ◽  
Gao Feng Quan ◽  
Zhao Ming Liu
Keyword(s):  
Magnesium Alloy ◽  
Strain Hardening ◽  
Room Temperature ◽  
Deformation Behaviour ◽  
Az31 Alloy ◽  
Strain Hardening Exponent ◽  
Surface Cracks ◽  
Compression Properties ◽  
Compression Behaviour ◽  
Az31 Mg Alloy

The microstructure, surface morphology, compression properties, deformation behaviour and strain hardening exponent of as-cast and as-extruded AZ31 Mg alloy after different annealing treatments were investigated. The results show that the compression properties are great different between cast AZ31 alloy and extruded AZ31 alloy. Extruded AZ31 alloy is discontinuous yield and on the surface no signs of damage have been observed; on the contrast, cast AZ31 alloy is continuous yield and shows wavy patterns, and the surface cracks can be easily found. In addition, there is a linear relationship between the strain hardening exponent in first deformation stage and the yield ratio. Further more, the twinning mechanism plays very different role in cast AZ31 alloy and extruded AZ31 alloy.

Microstructure and Mechanical Responses of Extruded Magnesium Alloy Sheets with Lithium Addition

2015 ◽  
Vol 816 ◽  
pp. 504-509 ◽  
Author(s):  
Qing Shan Yang ◽  
Bin Jiang ◽  
Jun Jie He ◽  
Zheng Yuan Gao ◽  
Jia Hong Dai ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Room Temperature ◽  
Texture Evolution ◽  
Tensile Tests ◽  
Extrusion Ratio ◽  
Basal Texture ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mechanical Responses ◽  
Room Temperature Ductility

After 5% lithium was added to AZ31 magnesium alloy, the alloy was extruded at 380oC with the extrusion ratio of 101. Mechanical responses and microstructure evolution were investigated. The microstructure and texture evolution were examined by electronic backscattered diffraction (EBSD) and X-ray diffraction (XRD). Tensile tests in the tensile directions of 0o, 45oand 90owere carried out at room temperature. Lithium addition brought about the strong divergence of the grain orientation and triggered the spread of the (0002) basal texture. The room temperature ductility of the extruded Mg alloy sheets was improved due to the tilted weak basal texture.

scholarly journals On the High Formability of AZ31-0.5Ca Magnesium Alloy

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2201 ◽  
Author(s):  
Umer Masood Chaudry ◽  
Tae Hoo Kim ◽  
Sang Duck Park ◽  
Ye Sik Kim ◽  
Kotiba Hamad ◽  
...  
Keyword(s):  
Az31 Alloy ◽  
Mg Alloy ◽  
Slip Systems ◽  
Basal Texture ◽  
Consistent Model ◽  
Az31 Mg Alloy ◽  
Self Consistent ◽  
Grain Misorientation ◽  
Critical Resolved Shear Stress ◽  
Electron Back Scattered Diffraction

In this work, we investigated the effect of Ca on the formability of the AZ31 Mg alloy. For this purpose, the microstructure, texture, mechanical properties and formability of AZ31 Mg alloy samples containing 0.5 wt. % Ca (AZ31-0.5Ca) were studied. For comparison, the performance of Ca-Free AZ31 alloy samples with similar grain size was also investigated. In addition, formability of this alloy was reached at a high punch speed. The results of this work showed that the addition of 0.5 wt. % Ca can enhance the formability of the AZ31 alloy, which was three times greater than that of the Ca-Free AZ31 alloy. The improved formability was attributed to the formation of (Mg,Al)2Ca particles (~1 μm), which, in turn, contribute to reducing the intensity of the strong basal texture during the primary processing of the alloy. The in-grain misorientation axis analysis determined by electron back-scattered diffraction and critical resolved shear stress calculations carried out by the viscoplastic self-consistent model showed that the non-basal slip systems could be activated in the AZ31-0.5Ca alloy.

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.

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.

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