An Investigation on the Anisotropic Plastic Behavior and Forming Limits of an Al-Mg-Li Alloy Sheet

2021 ◽  
Author(s):  
Yubao Wang ◽  
Cunsheng Zhang ◽  
Yinghao Wang ◽  
Guoqun Zhao ◽  
Liang Chen
Keyword(s):  
Alloy Sheet ◽  
Plastic Behavior ◽  
Forming Limits ◽  
Anisotropic Plastic

Modeling of Anisotropic Plastic Behavior of Advanced High Strength Steel Sheet TRIP 780

2011 ◽  
Vol 410 ◽  
pp. 232-235 ◽  
Author(s):  
Sansot Panich ◽  
Vitoon Uthaisangsuk ◽  
Surasak Suranuntchai ◽  
Suwat Jirathearanat
Keyword(s):  
High Strength Steel ◽  
Steel Sheet ◽  
Plastic Anisotropy ◽  
High Strength ◽  
Uniaxial Tensile ◽  
Plastic Behavior ◽  
Biaxial Test ◽  
Advanced High Strength Steel ◽  
Yield Criteria ◽  
Anisotropic Plastic

Anisotropic plastic behavior of advanced high strength steel sheet of grade TRIP780 (Transformation Induced Plasticity) was investigated using three different yield functions, namely, the von Mises’s isotropic, Hill’s anisotropic (Hill’48), and Barlat’s anisotropic (Yld2000-2d) criterion. Uniaxial tensile and balanced biaxial test were conducted for the examined steel in order to characterize flow behavior and plastic anisotropy for different stress states. Especially, disk compression test was performed for obtaining balanced r-value. All these data were used to determine the anisotropic coefficients. As a result, yield stresses and r-values for different directions were calculated according to these yield criteria. The results were compared with experimental data. To verify the modelling accuracy, tensile tests of various notched samples were carried out and stress-strain distributions in the critical area were characterized. By this manner, the effect of stress triaxiality due to different notched shapes on the strain localization calculated by the investigated yield criteria could be studied.

Forming limit analysis of Mg-2Zn-1.2Al-0.2Ca-0.2RE alloy sheet using ductile fracture models

2019 ◽  
Vol 29 (8) ◽  
pp. 1181-1198 ◽  
Author(s):  
Fei-Fan Li ◽  
Gang Fang ◽  
Ling-Yun Qian
Keyword(s):  
Magnesium Alloy ◽  
Ductile Fracture ◽  
Stress Triaxiality ◽  
Forming Limit Diagram ◽  
Alloy Sheet ◽  
Image Correlation ◽  
Forming Limit ◽  
Correlation Technique ◽  
Forming Limits ◽  
Fracture Models

This work was aimed to experimentally and theoretically investigate the formability of a new magnesium alloy sheet at room temperature. The fracture forming limit diagram was predicted by MMC3 and DF2014 models, where the non-linear strain path effect was taken into account by means of damage accumulation law. In order to obtain the instantaneous values of the stress triaxiality and the Lode parameter during the deformation process, strains tracked by digital image correlation technique were transformed into stresses based on the constitutive equations. The fracture forming limit diagram predicted by the fracture models was compared with the forming limits obtained by ball punch deformation tests. The prediction errors were evaluated by the accumulative damage values, which verified the advantages of ductile fracture models in predicting the forming limits of the magnesium alloy sheets.

Analysis of an Idealized Directionally Solidified FCC Material

1983 ◽  
Vol 105 (4) ◽  
pp. 307-312 ◽  
Author(s):  
J. H. Laflen
Keyword(s):  
Nonlinear Optimization ◽  
Crystalline Structure ◽  
Continuum Theory ◽  
Optimization Techniques ◽  
Plastic Behavior ◽  
Aircraft Engines ◽  
Local Orientation ◽  
Directionally Solidified ◽  
Grain Sizes ◽  
Anisotropic Plastic

Directionally solidified materials are being increasingly used in aircraft engines. These alloys are anisotropic due to the well aligned crystalline structure with additional considerations including large grain sizes and perturbations in the local orientation. In this paper, the Bishop-Hill method is combined with nonlinear optimization techniques to predict the anisotropic plastic behavior of an ideal directionally solidified FCC material subjected to off-axis uniaxial loadings. A comparison of these results is made with a continuum theory.

scholarly journals Anisotropic Plastic Behavior in an Extruded Long-Period Ordered Structure Mg90Y6.5Ni3.5 (at.%) Alloy

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 279
Author(s):  
Gerardo Garces ◽  
Rafael Barea ◽  
Andreas Stark ◽  
Norbert Schell
Keyword(s):  
Basal Plane ◽  
Extrusion Direction ◽  
Plastic Behavior ◽  
Ordered Structure ◽  
Lpso Phase ◽  
Long Period ◽  
Anisotropic Plastic ◽  
The Difference ◽  
Internal Strains

The Mg90Y6.5Ni3.5 alloy composed almost completely of the Long-Period-Stacking-Ordered (LPSO) phase has been prepared by casting and extrusion at high temperature. An elongated microstructure is obtained where the LPSO phase with 18R crystal structure is oriented with its basal plane parallel to the extrusion direction. Islands of α-magnesium are located between the LPSO grains. The mechanical properties of the alloy are highly anisotropic and depend on the stress sign as well as the relative orientation between the stress and the extrusion axes. The alloy is stronger when it is compressed along the extrusion direction. Under this configuration, the slip of <a> dislocations in the basal plane is highly limited. However, the activation of kinking induces an increase in the plastic deformation. In the transversal extrusion direction, some grains deform by the activation of basal slip. The difference in the yield stress between the different stress configurations decreases with the increase in the test temperature. The evolution of internal strains obtained during in-situ compressive experiments reveals that tensile twinning is not activated in the LPSO phase.

Forming Limits Prediction of FCC Sheet Metal Adopting Crystal Plasticity

2007 ◽  
Vol 340-341 ◽  
pp. 179-186
Author(s):  
Wing Bun Lee ◽  
Yi Ping Chen ◽  
Sandy To
Keyword(s):  
Sheet Metal ◽  
Crystal Plasticity ◽  
Initial Imperfection ◽  
Rate Sensitivity ◽  
Alloy Sheet ◽  
Forming Limits ◽  
Factors Affecting ◽  
Rate Dependent ◽  
Initial Texture ◽  
Process Factors

A rate-dependent crystal plasticity constitutive model together with Marciniak- Kuczynski(M-K) approach is employed to perform numerical simulations of forming limits diagrams(FLDs). An initial imperfection in terms of a narrow band is adopted to initialize the sheet necking. Homogeneous deformations inside and outside the band are assumed and the enforcement of compatibility and equilibrium conditions is required only on the band interface. Constitutive computations are carried out on two aggregates of FCC crystal grains, with each representing one of the two zones, respectively. Taylor homogenization assumption is employed to establish the link of stress between single crystal and polycrystal, and to derive an average response of the aggregates. The same initial texture is imparted to the two aggregates and their evolutions will be traced in the necking process. Factors affecting the FLDs prediction, such as imperfection intensity, initial texture, strain rate sensitivity and crystal elasticity will be taken into account. The above procedure will be applied to an annealed aluminium alloy sheet metal

scholarly journals Anisotropic Plastic Behavior of Additively Manufactured PH1 Steel

2021 ◽  
Author(s):  
Wenqi Liu ◽  
Zinan Li ◽  
Sven Bossuyt ◽  
Antti Forsström ◽  
Zaiqing Que ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Thermal History ◽  
Deformation Behavior ◽  
Uniaxial Tensile ◽  
Plastic Behavior ◽  
Geometrical Shape ◽  
Anisotropic Plasticity ◽  
Plastic Deformation Behavior ◽  
Anisotropic Plastic

Metals made by additive manufacturing (AM) have intensely augmented over the past decade for customizing complex structured products in the aerospace industry, automotive, and biomedical engineering. However, for AM fabricated steels, the correlation between the microstructure and mechanical properties is yet a challenging task with limited reports. To realize optimization and material design during the AM process, it is imperative to understand the influence of the microstructural features on the mechanical properties of AM fabricated steels. In the present study, three material blocks with 120×25×15 mm3 dimensions are produced from PH1 steel powder using powder bed fusion (PBF) technology to investigate the anisotropic plastic deformation behavior arising from the manufacturing process. Despite being identical in geometrical shape, the manufactured blocks are designed distinguishingly with various coordinate transformations, i.e. alternating the orientation of the block in the building direction (z) and the substrate plate (x, y). Uniaxial tensile tests are performed along the length direction of each specimen to characterize the anisotropic plastic deformation behavior. The distinctly anisotropic plasticity behavior in terms of strength and ductility are observed in the AM PH1 steel, which is explained by their varied microstructure affected by the thermal history of blocks. It could also be revealed that the thermal history in the AM blocks is influenced by the block geometry even though the same process parameters are employed.

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