scholarly journals Texture-Based Optimization of Crystal Plasticity Parameters: Application to Zinc and Its Alloy

2021 ◽  
Author(s):  
Karol Frydrych ◽  
Anna Jarzębska ◽  
Saketh Virupakshi ◽  
Katarzyna Kowalczyk-Gajewska ◽  
Magdalena Bieda ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Crystal Plasticity ◽  
Fitness Function ◽  
Texture Evolution ◽  
Hydrostatic Extrusion ◽  
Numerical Comparison ◽  
Active Deformation ◽  
Pure Zinc ◽  
Hexagonal Close Packed ◽  
Measured Stress

AbstractEvolutionary algorithms have become an extensively used tool for identification of crystal plasticity parameters of hexagonal close packed metals and alloys. However, the fitness functions were usually built using the experimentally measured stress–strain curves. Here, the fitness function is built by means of numerical comparison of the simulated and experimental textures. Namely, the normalized texture difference index is minimized. The evolutionary algorithm with the newly developed fitness function is tested by performing crystal plasticity parameter optimization for both pure zinc and zinc-magnesium alloy. These materials are promising candidates for bioabsorbable implants due to good biocompatibility and optimal corrosion rate. Although their mechanical properties in the as-cast state do not fulfill the requirements, they can be increased by means of hydrostatic extrusion. The developed modeling approach enabled acquisition of the crystal plasticity parameters and analysis of the active deformation mechanisms in zinc and zinc-magnesium alloy subjected to hydrostatic extrusion. It was shown that although slip systems are the main deformation carrier, compressive twinning plays an important role in texture evolution. However, the texture is also partially affected by dynamic recrystallization which is not considered within the developed framework.

Development of Multi-Scale Thermo-Crystal Plasticity Finite Element Method to Analyze Plastic Deformation of Magnesium Alloy

2017 ◽  
Author(s):  
Sayuki Kashiwagi ◽  
Yoshihiro Tomita ◽  
Toshihiko Yamaguchi ◽  
Koji Yamamoto ◽  
Yusuke Morita ◽  
...  
Keyword(s):  
Finite Element ◽  
High Temperature ◽  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Crystal Plasticity ◽  
Texture Evolution ◽  
Fe Analysis ◽  
Numerical Code ◽  
Multi Scale ◽  
Crystal Texture

To clarify the deformation induced crystal texture evolution of rolled and drawn magnesium alloy sheets with strong basal texture, we developed a multi-scale finite element (FE) analysis code based on the homogenization theory, which combines the microscopic poly-crystal structure and the macroscopic continuum. In our crystal plasticity constitutive equation of magnesium alloys, the plastic work induced temperature rise and twinning in the crystal slip systems was implemented into our multi-scale FE analysis code. To validate our numerical code to correctly predict macro and micro deformations including the crystal texture evolution, the tension and compression along normal direction (ND) and rolling direction (RD) at the room temperature 300K and the high temperature 673K were numerically investigated. It is confirmed that numerical results showed the similar tendency to experimentally obtained results including the strengthening the basal texuture in compression along ND, the twinning, the polarity of twinning and the temperature-dependency that twinning is hardly appear at high temperature. Finaly, we concluded that our numerical code can predict the plastic strain induced texture evolution of magnesium alloys.

Deformation and texture evolution in AZ31 magnesium alloy during uniaxial loading

2006 ◽  
Vol 54 (2) ◽  
pp. 549-562 ◽  
Author(s):  
S.-B. Yi ◽  
C.H.J. Davies ◽  
H.-G. Brokmeier ◽  
R.E. Bolmaro ◽  
K.U. Kainer ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Texture Evolution ◽  
Uniaxial Loading ◽  
Az31 Magnesium Alloy

Crystal Plasticity Predictions of Forward-Reverse Simple Shear Flow Stress

2011 ◽  
Vol 702-703 ◽  
pp. 204-207 ◽  
Author(s):  
Young Ung Jeong ◽  
Frédéric Barlat ◽  
Myoung Gyu Lee
Keyword(s):  
Flow Stress ◽  
Crystal Plasticity ◽  
Simple Shear ◽  
Bauschinger Effect ◽  
Texture Evolution ◽  
Simple Shear Flow ◽  
Plasticity Model ◽  
Lower Yield Stress ◽  
Crystal Plasticity Model ◽  
Stress Reversals

The flow stress behavior of a bake-hardenable steel during a few simple shear cycles is investigated using a crystal plasticity model. The simple shear test provides a stable way to reverse the loading direction. Stress reversals were accompanied with a lower yield stress, i.e., the Bauschinger effect, followed by a transient hardening stage with a plateau region and, permanent softening. The origins of these three distinct stages are discussed using a crystal plasticity model. To this end, the representative discrete grain set is tuned to capture such behavior by coupling slip system hardening appropriately. The simulated results are compared with experimental forward-reverse simple shear stress-strain curves. It is shown that the characteristic flow stress stages are linked to texture evolution and to the Bauschinger effect acting on the different slip systems.

scholarly journals Deformation Texture Evolution in Flat Profile AlMgSi Extrusions: Experiments, FEM, and Crystal Plasticity Modeling

2021 ◽  
Vol 8 ◽  
Author(s):  
Tomas Manik ◽  
Knut Marthinsen ◽  
Kai Zhang ◽  
Arash Imani Aria ◽  
Bjørn Holmedal
Keyword(s):  
Strain Rate ◽  
Strain Rate Sensitivity ◽  
Crystal Plasticity ◽  
Texture Evolution ◽  
Rate Sensitivity ◽  
Deformation Texture ◽  
Fiber Texture ◽  
Electron Back Scatter Diffraction ◽  
Slip Systems ◽  
Flat Profile

In the present work, the deformation textures during flat profile extrusion from round billets of an AA6063 and an AA6082 aluminium alloy have been numerically modeled by coupling FEM flow simulations and crystal plasticity simulations and compared to experimentally measured textures obtained by electron back-scatter diffraction (EBSD). The AA6063 alloy was extruded at a relatively low temperature (350°C), while the AA6082 alloy, containing dispersoids that prevent recrystallization, was extruded at a higher temperature (500°C). Both alloys were water quenched at the exit of the die, to maintain the deformation texture after extrusion. In the center of the profiles, both alloys exhibit a conventional β-fiber texture and the Cube component, which was significantly stronger at the highest extrusion temperature. The classical full-constraint (FC)-Taylor and the Alamel grain cluster model were employed for the texture predictions. Both models were implemented using the regularized single crystal yield surface. This approach enables activation of any number and type of slip systems, as well as accounting for strain rate sensitivity, which are important at 350°C and 500°C. The strength of the nonoctahedral slips and the strain-rate sensitivity were varied by a global optimization algorithm. At 350°C, a good fit could be obtained both with the FC Taylor and the Alamel model, although the Alamel model clearly performs the best. However, even with rate sensitivity and nonoctahedral slip systems invoked, none of the models are capable of predicting the strong Cube component observed experimentally at 500°C.

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