scholarly journals Experimental and Numerical Study of Texture Evolution and Anisotropic Plastic Deformation of Pure Magnesium under Various Strain Paths

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Hamad F. Alharbi ◽  
Monis Luqman ◽  
Ehab El-Danaf ◽  
Nabeel H. Alharthi
Keyword(s):  
Strain Hardening ◽  
Uniaxial Tension ◽  
Plane Strain ◽  
Texture Evolution ◽  
Plane Strain Compression ◽  
Pure Magnesium ◽  
Deformation Mechanisms ◽  
Slip Systems ◽  
Simple Compression ◽  
Strain Paths

The deformation behavior and texture evolution of pure magnesium were investigated during plane strain compression, simple compression, and uniaxial tension at room temperature. The distinctive stages in the measured anisotropic stress-strain responses and numerically computed strain-hardening rates were correlated with texture and deformation mechanisms. More specifically, in plane strain compression and simple compression, the onset of tensile twins and the accompanying texture-hardening effect were associated with the initial high strain-hardening rates observed in specimens loaded in directions perpendicular to the crystallographic c-axis in most of the grains. The subsequent drop in strain-hardening rates in these samples was correlated with the exhaustion of tensile twins and the activation of pyramidal <c+a> slip systems. The falling strain-hardening rates were observed in simple compression and plane strain compression with loading directions parallel to the c-axis where the second pyramidal <c+a> slip systems were the only slip families that can accommodate deformation. For uniaxial tension with the basal plane parallel to the tensile axis, the prismatic <a> and second pyramidal <c+a> slips are the main deformation mechanisms. The predicted relative slip and twin activities from the crystal plasticity simulations clearly showed the effect of texture on the type of activated deformation mechanisms.

Texture Formation Behaviour during High-Temperature Plane Strain Compression Deformation in AZ91 Magnesium Alloy

2018 ◽  
Vol 941 ◽  
pp. 1198-1202
Author(s):  
Dong Keun Han ◽  
Min Soo Park ◽  
Han Sang Kwon ◽  
Kwon Hoo Kim
Keyword(s):  
High Temperature ◽  
Strain Rate ◽  
Plane Strain ◽  
Texture Evolution ◽  
Plane Strain Compression ◽  
Deformation Condition ◽  
Rolled Plate ◽  
Pole Density ◽  
Texture Formation ◽  
Compression Tests

In previous study, it was investigated texture formation behaviour of high-temperature plane strain compression test at 723K, under a strain rate of 5.0. It was found that the main texture component and it was sharpness vary depending on deformation conditions. To clarify the characteristic of texture formation behaviour, it is necessary to investigate at various deformation condition. Therefore, in this study, is investigating the influence or texture formation behaviour and strain, strain rate at 673K. Three kinds of specimens with different initial textures were machined out from a rolled plate having a <0001> texture. The plane strain compression tests were conducted at a temperature 673K, and a strain rate of 5.0, with strain between-0.4 to-1.0. After compression tests, the specimens were immediately quenched in oil. The texture evolution was conducted by the Schulz reflection method using Cu Kα radiation and EBSD. Before the deformation, {0001} of specimen A was accumulated in the center of pole figure. The {0001} of specimen B was accumulated at the RD direction. The {0001} of specimen C was accumulated TD direction. As a result, work softening is observed in all the cases at the true stress – true strain curve for three types of specimens. After deformation, the maximum pole density of increases with increasing strain. In this study, it was found that the stable orientation was (0001)<100> and (0001)<110> during deformation.

Deformation mechanisms of a rolled Mg–6Al–3Sn alloy during plane strain compression

2013 ◽  
Vol 578 ◽  
pp. 362-369 ◽  
Author(s):  
Lei Zhang ◽  
Chun-Guo Liu ◽  
Hui-Yuan Wang ◽  
Xiao-Long Nan ◽  
Zhi-Qiang Wu ◽  
...  
Keyword(s):  
Plane Strain ◽  
Plane Strain Compression ◽  
Deformation Mechanisms

scholarly journals Prediction of Strain Path Changing Effect on Forming Limits of AA 6111-T4 Based on A Shear Ductile Fracture Criterion

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 546
Author(s):  
Silin Luo ◽  
Gang Yang ◽  
Yanshan Lou ◽  
Yongqian Xu
Keyword(s):  
Ductile Fracture ◽  
Uniaxial Tension ◽  
Plane Strain ◽  
Strain Path ◽  
Fracture Criterion ◽  
Kinematic Hardening ◽  
Isotropic Hardening ◽  
Ductile Fracture Criterion ◽  
Plane Strain Tension ◽  
Strain Paths

Strain path changing is a phenomenon in the stamping of complex panels or multiple-step stamping processes. In this study, the influence of the strain path changing effect was investigated and assessed for an aluminum alloy of 6111-T4 with a shear ductile fracture criterion. Plastic deformation of the alloy was modeled by an anisotropic Drucker yield function with the assumption of normal anisotropy. Then the shear ductile fracture criterion was calibrated by the fracture strains at uniaxial tension, plane strain tension and equibiaxial tension under proportional loading conditions. The calibrated fracture criterion was utilized to predict forming limit curves (FLCs) of the alloy stretched under bilinear strain paths. The analyzed bilinear strain paths included biaxial tension after uniaxial tension, plane strain tension and equibiaxial tension. The predicted FLCs of bilinear strain paths were compared with experimental results. The comparison showed that the shear ductile fracture criterion could reasonably describe the effect of strain path changing on FLCs, but its accuracy was poor for some bilinear paths, such as uniaxial tension followed by equibiaxial tension and equibiaxial tension followed by plane strain tension. Kinematic hardening is suggested to substitute the isotropic hardening assumption for better prediction of FLCs with strain path changing effect.

scholarly journals Mechanical Behavior of a Series of Copolyester Blends near the Glass Transition: Monotonic and Load-Hold Behavior in Compression

2012 ◽  
Vol 2012 ◽  
pp. 1-9
Author(s):  
Gurucharan Chandrasekaran ◽  
Rebecca B. Dupaix
Keyword(s):  
Mechanical Behavior ◽  
Strain Hardening ◽  
Plane Strain ◽  
Plane Strain Compression ◽  
Strain Rates ◽  
Compression Load ◽  
Hold Period ◽  
Poly Ethylene Terephthalate ◽  
Strain Induced Crystallization ◽  
Poly Ethylene

Monotonic loading tests were conducted on five commercial blends of poly(ethylene terephthalate) (PET) and poly(1,4-cyclohexylenedimethylene terephthalate) (PCT) at temperatures of 90°C and 100°C and strain rates of 0.1/s, 0.05/s, and 0.005/s in uniaxial and plane strain compression. On comparing the mechanical behavior of the five materials, it was found that the behavior of the low-PCT content materials was different from the high-PCT content materials only at conditions that favored strain-induced crystallization, particularly in plane strain compression. Load-hold tests were also conducted on three of the blends with similar results to the monotonic tests. Material differences were only pronounced at certain conditions, and in these cases the low-PCT content materials showed increased strain hardening after the hold period while the high-PCT content material did not. Therefore, it was found that the addition of a hold period was not exclusively required to observe differences in the crystallizable materials over the noncrystallizing blends. The increased strain hardening likely associated with crystallization in PET was only observed when the following conditions were met: (i) strain rates of 0.1/s and above, (ii) temperatures of 90°C–100°C, (iii) plane strain compression, and (iv) after a certain level of deformation.

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