scholarly journals Simulation of dynamic recrystallization of a magnesium alloy with a cellular automaton method coupled with adaptive activation energy and matrix deformation topology

2021 ◽  
Vol 8 ◽  
pp. 11
Author(s):  
Sibing Wang ◽  
Wenchen Xu ◽  
He Wu ◽  
Ranxu Yuan ◽  
Xueze Jin ◽  
...  
Keyword(s):  
Activation Energy ◽  
Magnesium Alloy ◽  
Cellular Automata ◽  
Dynamic Recrystallization ◽  
Nucleation And Growth ◽  
Model Combining ◽  
Matrix Deformation ◽  
Ca Model ◽  
Simulation Results ◽  
Cellular Automaton Method

The cellular automata (CA) model combining topological deformation and adaptive activation energy was successfully constructed to analyze the thermal dynamic recrystallization of the magnesium alloy (AZ61). The simulation datum shown that the recrystallization nucleation located on the grain boundary (GB) once the density of dislocation accumulated to specific value, and the result presents a typical characteristics i.e., repeated nucleation and growth. The simulation results agree well with the experimental results because the activation energy affects recrystallization by affecting nucleation rate.

scholarly journals Modeling of Dynamic Recrystallization Behavior of As-Extruded AM50 Magnesium Alloy during Hot Compression by a Cellular Automaton Method

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 75
Author(s):  
Dayu Shu ◽  
Jing Wang ◽  
Menghao Jiang ◽  
Gang Chen ◽  
Liwei Lu ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Cellular Automaton ◽  
Volume Fraction ◽  
Strain Rate Range ◽  
Dynamic Recrystallization Behavior ◽  
Ca Model ◽  
Cellular Automaton Method ◽  
Experimental Values

The dynamic recrystallization (DRX) behavior of as-extruded AM50 magnesium alloy was modelled and simulated by a cellular automaton (CA) method. Isothermal compression experiments were conducted, and the characteristic parameters in the CA model were obtained by the testing stress–strain flow curves in a wide temperature range of 250–450 °C and strain rate range of 0.001–10 s−1. The flow stress, DRX volume fraction and DRX grain size of the as-extruded AM50 magnesium alloy were predicted by CA simulation. The results showed that the DRX behavior of the studied magnesium alloy was susceptive with the temperature and strain rate; meanwhile, the prediction results were approximate to the experimental values, indicating that the developed CA model can make a confident estimation on the DRX behavior of the as-extruded AM50 magnesium alloy in high temperature conditions.

A STUDY OF DYNAMIC RECRYSTALLIZATION IN TA15 TITANIUM ALLOY DURING HOT DEFORMATION BY CELLULAR AUTOMATA MODEL

2009 ◽  
Vol 23 (06n07) ◽  
pp. 934-939 ◽  
Author(s):  
DONG HE ◽  
JING CHUAN ZHU ◽  
YANG WANG ◽  
YONG LIU
Keyword(s):  
Titanium Alloy ◽  
Flow Stress ◽  
Dislocation Density ◽  
Cellular Automata ◽  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Hot Deformation ◽  
Temperature Filed ◽  
Ca Model ◽  
Grain Growth Model

The dynamic recrystallization (DRX) of TA 15 ( Ti -6 Al -2 Zr -1 Mo -1 V ) titanium alloy during the hot deformation process was studied by the Cellular Automata (CA) model which is base on the dislocation density theory. To build the CA model, the dislocation density model, dynamic recovery model, nucleation model and grain growth model were introduced and developed. The influences of strain rate on the microstructure evolution and flow stress character were investigated which shows that high strain rate leads to later DRX appearance, high flow stress peak value, small mean size of recrystallizing grains( R -grains) and low DRX percentage, but they have the similar Avrami curve. The characteristic of DRX process in a modeling non-uniform temperature filed (NTF) has been studied. All the simulation results show good agreement with the pioneer's work and experimental results.

Validation of Cellular Automata Model of Dynamic Recrystallization

2015 ◽  
Vol 651-653 ◽  
pp. 581-586 ◽  
Author(s):  
Mateusz Sitko ◽  
Łukasz Madej ◽  
Maciej Pietrzyk
Keyword(s):  
Cellular Automata ◽  
Dynamic Recrystallization ◽  
Internal Variables ◽  
Cellular Automata Model ◽  
Proposed Model ◽  
Digital Material ◽  
Ca Model ◽  
Transition Rules ◽  
Development And Validation ◽  
Neighborhood Type

Development and validation of the micro scale cellular automata (CA) model of dynamic recrystallization (DRX) were the main goals of the present paper. Major assumptions of the developed CA DRX model, which is based on the Digital Material Representation (DMR) concept, are described. Parameters like neighborhood type, state and internal variables of the proposed model and their influence on final results are presented and discussed. Particular attention was put on description of the developed transition rules used to replicate mechanisms leading to dynamic recrystallization. Finally, obtained results in the form of flow stress curves are compared with the experimental predictions.

A Simplified CA Method for Simulating the Microstructure of Magnesium Alloy Components

2007 ◽  
Vol 561-565 ◽  
pp. 1797-1800 ◽  
Author(s):  
Liang Huo ◽  
Zhi Qiang Han ◽  
Zhi Yong Liu ◽  
Bai Cheng Liu
Keyword(s):  
Magnesium Alloy ◽  
Solidification Process ◽  
Eutectic Structure ◽  
Competitive Growth ◽  
Az91d Magnesium Alloy ◽  
Ca Model ◽  
Simulation Results ◽  
Evolution Of Microstructure ◽  
Crystallographic Orientations ◽  
Good Agreement

In this paper, a simplified cellular automaton (CA) model was proposed for modeling the evolution of microstructure in solidification process of AZ91D magnesium alloy. Since the calculation time was significantly reduced, it might be used to predict the microstructure field of a real Mg component after solidification. The stochastic nucleation, competitive growth processes of many grains with various crystallographic orientations and the formation of eutectic structure were also taken into account. Furthermore, step castings were poured with sand and permanent molds and metallographic experiments were carried out for validating the developed models. It was shown that the simulation results are in good agreement with those obtained in the experiments.

MODELING THE RAILWAY TRAFFIC USING CELLULAR AUTOMATA MODEL

2005 ◽  
Vol 16 (06) ◽  
pp. 921-932 ◽  
Author(s):  
KE-PING LI ◽  
ZI-YOU GAO ◽  
BIN NING
Keyword(s):  
Cellular Automata ◽  
Signaling System ◽  
Highway Traffic ◽  
Cellular Automata Model ◽  
Railway Traffic ◽  
Probabilistic Cellular Automaton ◽  
Block Scheme ◽  
Ca Model ◽  
Simulation Results ◽  
Flow States

The NaSch model is a probabilistic cellular automaton (CA) model for the description of single-lane highway traffic. Based on this model, we propose a new cellular automata model for the railway traffic. The signaling system adopted in this work is the moving block signaling system. In our model, the distance between the following train and its leading train takes into account the velocity of the leading train. The simulation results demonstrate that our model is suitable for simulating the railway traffic. Compared our scheme to the traditional moving-space-block scheme, it is obvious that using our scheme, not only the line capacity can be increased, but also the traffic flow states are safer.

scholarly journals Microstructure evolution of 20Cr steel spider during cold forging using cellular automaton method

2018 ◽  
Vol 24 (1) ◽  
pp. 43
Author(s):  
Kun Xia Wei ◽  
Ling Niu ◽  
Wei Wei ◽  
Qing Bo Du ◽  
Igor V. Alexandrov ◽  
...  
Keyword(s):  
Grain Size ◽  
Microstructure Evolution ◽  
Effective Strain ◽  
Numerical Approach ◽  
Cold Forging ◽  
Forging Process ◽  
Microhardness Distribution ◽  
Ca Model ◽  
Simulation Results ◽  
Cellular Automaton Method

<p class="AMSmaintext"><span lang="EN-GB">The microstructure evolution of 20Cr steel spider in the cold forging process was simulated and analyzed by CA method, and verified by the experimental results. The CA simulation results show that the grain size becomes smaller with an increase of forging reduction. When the reduction is 60%, the grain size is the smallest. After that, the microstructure is inhomogeneous. At the same forging reduction, the microhardness at the root of the pin is higher than that at the head of the pin. It is well agreed with the distribution of the effective strain. The CA results agree well with the experimental data in terms of microstructure evolution and microhardness distribution, suggesting that the CA model is a reliable numerical approach for predicting microstructure evolution during cold forging for 20Cr steel spider.</span></p>

Reconstruction Method for Complex Groove of Milling Insert Using Local Rule of Cellular Automata

2007 ◽  
Author(s):  
Guangyu Tan ◽  
Guangjun Liu ◽  
Guanghui Li ◽  
Yiming Rong ◽  
Hui Song
Keyword(s):  
Cellular Automata ◽  
Fem Simulation ◽  
The State ◽  
Reconstruction Method ◽  
Discrete Variables ◽  
Regular Grid ◽  
Local Rule ◽  
Ca Model ◽  
Simulation Results ◽  
Square Cells

This paper presents a groove reconstruction method based on the local rule of Cellular Automata (CA). A local rule for groove reconstruction is proposed to design and optimize the groove of milling insert. The insert is firstly divided into a large number of cells that typically form a regular grid over the domain. The domain consists of regular square cells with discrete variables and the discrete CA model is built. As the cells in the CA domain only interact with their neighboring cells when performing local computations, the governing equation for the whole domain is not necessary. Then the states of cells are modified according to the local rule applied. The state of the entire system is updated based on the state of the cell and its neighboring cells. Collectively, these cells’ states define the state of the entire domain, and the groove can be reconstructed according to the state of the domain. The reconstructed groove is tested by a FEM simulation. The simulation results show that the reconstructed groove has a satisfied performance on the stress field.

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