Constitutive Models for AZ31 Magnesium Alloys

2008 ◽  
Vol 367 ◽  
pp. 87-94 ◽  
Author(s):  
Carlo Bruni ◽  
Lorenzo Donati ◽  
Mohamad El Mehtedi ◽  
M. Simoncini
Keyword(s):  
Magnesium Alloy ◽  
Constitutive Models ◽  
Extrusion Process ◽  
Flow Behaviour ◽  
Az31 Magnesium Alloy ◽  
Strain Rates ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Different Temperatures ◽  
Power Law Equation

The present investigation aims at studying and modelling the flow behaviour of the AZ31 magnesium alloy by means of torsion tests performed in extended ranges of temperature and strain rates. Two types of rheological models were considered. The former is based on the power law equation, whilst the latter is based on the Sellars and Tegart approach. The effectiveness of the two constitutive models in describing the flow behaviour of the AZ31 magnesium alloy under investigation was evaluated. It was observed that both the equations are able to predict the flow behaviour of the material at different temperatures and strain rates. In particular, the former is very effective in predicting the hardening stage of the flow curve, whilst the latter allows to fit the softening stage. The models were used for the finite element analysis of a complex extrusion process and the results, in terms of the load-stroke curves, compared to each other.

Warm Stamping of Cell-Phone Cases with AZ31 Magnesium-Alloy Sheets

2010 ◽  
Vol 154-155 ◽  
pp. 1826-1829 ◽  
Author(s):  
Fuh Kuo Chen ◽  
Chih Kun Chang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Elevated Temperature ◽  
Magnesium Alloy ◽  
Cell Phone ◽  
Az31 Magnesium Alloy ◽  
Element Analysis ◽  
Stamping Process ◽  
The Finite Element Analysis ◽  
Forming Temperature

The stamping process for manufacturing cell phone cases with magnesium alloy AZ31 sheets was studied using both the experimental approach and the finite element analysis. The formability of AZ31 magnesium-alloy sheet at elevated temperatures was studied first. The experimental results reveal that the forming of AZ31 sheets becomes possible as long as the sheet is heated to an elevated temperature and 200oC is an optimum forming temperature to start with. An optimum stamping process, including die geometry, forming temperature, and blank dimension, for manufacturing the cell phone cases was examined by the finite element analysis. The finite element analyses performed for the cell phone were validated by the good agreement between the simulation results and the experimental data. It also confirms that the cell phone cases can be produced with AZ31 magnesium-alloy sheets at elevated temperature by the stamping process. It provides an alternative to the electronics industry in the application of magnesium alloys.

Extrusion Limit Diagram of Mg Alloy by Using Finite Element Method

2014 ◽  
Vol 622-623 ◽  
pp. 581-587
Author(s):  
Sang Kon Lee ◽  
Seong Yun Lee ◽  
In Kyu Lee ◽  
Myeong Sik Jeong ◽  
Yong Jae Jo ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Magnesium Alloy ◽  
Surface Defect ◽  
Process Condition ◽  
Extrusion Process ◽  
Strain Rates ◽  
Extrusion Speed ◽  
Element Analysis ◽  
Porthole Extrusion

In order to prevent the surface defect in the magnesium alloy extrusion process, it is important to set an appropriate process condition. The extrusion limit diagram is very useful to achieve the maximum extrusion speed without surface defect. In this study, the extrusion limit diagram for the magnesium alloy extrusion is constructed by using extrusion experiment and finite element analysis. For finite element analysis hot compression test is carried out to obtain the effective stress and stain curves according to the various strain rates and temperatures. The effectiveness of the constructed extrusion limit diagram is verified through the porthole extrusion experiment for producing the magnesium alloy bumper beam.

A Study on the Phenomenological Constitutive Models of AZ80 and AZ31 Magnesium Alloy Forming at Elevated Temperatures

2011 ◽  
Vol 328-330 ◽  
pp. 2394-2399 ◽  
Author(s):  
Yong Xue ◽  
Zhi Min Zhang ◽  
Yao Jin Wu ◽  
Guang Lu
Keyword(s):  
Magnesium Alloy ◽  
Strain Softening ◽  
Elevated Temperatures ◽  
Constitutive Models ◽  
Az31 Alloy ◽  
Az31 Magnesium Alloy ◽  
Strain Rates ◽  
Strain And Strain Rate ◽  
Process Simulator ◽  
Temperature Strain

Quantities AZ80 and AZ31 magnesium alloy billets were compressed with 60% height reduction on hot process simulator at 150,200,250,300,350,400,450°C under strain rates of 0.001, 0.01, 0.1,1 and 10s-1.A constitutive model with a few parameters is used to characterize the dynamic recrystallization strain softening of AZ80 and AZ31 alloy, which comprehensively reflect the effects of the deformation temperature, strain and strain rate on flow stress.

Critical damage value of AZ31B magnesium alloy with different temperatures and strain rates

Rare Metals ◽  
2015 ◽  
Author(s):  
Jing-Ren Dong ◽  
Ding-Fei Zhang ◽  
Yu-Feng Dong ◽  
Fu-Sheng Pan ◽  
Sen-Sen Chai
Keyword(s):  
Magnesium Alloy ◽  
Strain Rates ◽  
Az31b Magnesium Alloy ◽  
Different Temperatures ◽  
Critical Damage

Constitutive Equation for 3104 Alloy at High Temperatures in Consideration of Strain

2016 ◽  
Vol 35 (6) ◽  
pp. 599-605 ◽  
Author(s):  
Fuqiang Zhen ◽  
Jianlin Sun ◽  
Jian Li
Keyword(s):  
Hot Deformation ◽  
Flow Behavior ◽  
Temperature Correction ◽  
Strain Rates ◽  
Compression Tests ◽  
Hot Deformation Behavior ◽  
Element Analysis ◽  
Hollomon Parameter ◽  
The Finite Element Analysis ◽  
Effects Of Temperature

AbstractThe flow behavior of 3104 aluminum alloy was investigated at temperatures ranging from 250°C to 500°C, and strain rates from 0.01 to 10 s−1 by isothermal compression tests. The true stress–strain curves were obtained from the measured load–stroke data and then modified by friction and temperature correction. The effects of temperature and strain rate on hot deformation behavior were represented by Zener–Hollomon parameter including Arrhenius term. Additionally, the influence of strain was incorporated considering the effect of strain on material constants. The derived constitution equation was applied to the finite element analysis of hot compression. The results show that the simulated force is consistent with the measured one. Consequently, the developed constitution equation is valid and feasible for numerical simulation in hot deformation process of 3104 alloy.

Investigation of Corner Cavity Formation During Backward Cup Extrusion Process Using Finite Element Method

2009 ◽  
Author(s):  
Arash Khajeh ◽  
Ramin Ebrahimi ◽  
Mohammad Mohsen Moshksar
Keyword(s):  
Finite Element ◽  
Extrusion Process ◽  
Critical Value ◽  
Cavity Formation ◽  
Element Analysis ◽  
Temporal Prediction ◽  
Element Simulation ◽  
The Finite Element Analysis ◽  
Considerable Impact ◽  
Reduction Of Area

This study focuses on the finite element analysis of the formation of corner cavity defect during the Backward Cup Extrusion (BCE) process. In the final stage of this process, when the bottom thickness reaches to a critical value this defect will be appear as a circumferential defect in the corner of the cup. In addition, this research examines the temporal prediction of onset of corner cavity formation in the various amounts of the reduction of areas. The finite element simulation results were compared with those of the experimental, indicating that the amount of the reduction of area and that of the friction coefficient have considerable impact on the onset of corner cavity formation during the BCE process.

scholarly journals Recrystallization Microstructure Prediction of a Hot-Rolled AZ31 Magnesium Alloy Sheet by Using the Cellular Automata Method

2019 ◽  
Vol 2019 ◽  
pp. 1-15
Author(s):  
Ming Chen ◽  
Xiaodong Hu ◽  
Hongyang Zhao ◽  
Dongying Ju
Keyword(s):  
Flow Stress ◽  
Magnesium Alloy ◽  
Cellular Automata ◽  
Process Analysis ◽  
Rolling Process ◽  
Alloy Sheet ◽  
Az31 Magnesium Alloy ◽  
Rolled Sheet ◽  
Element Analysis ◽  
Hot Rolled

A large reduction rolling process was used to obtain complete dynamic recrystallization (DRX) microstructures with fine recrystallization grains. Based on the hyperbolic sinusoidal equation that included an Arrhenius term, a constitutive model of flow stress was established for the unidirectional solidification sheet of AZ31 magnesium alloy. Furthermore, discretized by the cellular automata (CA) method, a real-time nucleation equation coupled flow stress was developed for the numerical simulation of the microstructural evolution during DRX. The stress and strain results of finite element analysis were inducted to CA simulation to bridge the macroscopic rolling process analysis with the microscopic DRX activities. Considering that the nucleation of recrystallization may occur at the grain and R-grain boundary, the DRX processes under different deformation conditions were simulated. The evolution of microstructure, percentages of DRX, and sizes of recrystallization grains were discussed in detail. Results of DRX simulation were compared with those from electron backscatter diffraction analysis, and the simulated microstructure was in good agreement with the actual pattern obtained using experiment analysis. The simulation technique provides a flexible way for predicting the morphological variations of DRX microstructure accompanied with plastic deformation on a hot-rolled sheet.

Parallel Extrusion of Aluminum Alloy Heat Sink with Round-Fin

2013 ◽  
Vol 739 ◽  
pp. 131-135
Author(s):  
Li Han Zhang ◽  
Ke Sheng Wang ◽  
Yu Han ◽  
Jia Yu Ying
Keyword(s):  
Heat Sink ◽  
Material Flow ◽  
Extrusion Process ◽  
Element Analysis ◽  
Automotive Lighting ◽  
Metal Sheets ◽  
The Finite Element Analysis ◽  
Alloy Heat ◽  
Flow Through ◽  
Good Agreement

Parallel extrusion is a combined extrusion process for forming round-fin heat sink on thick metal sheets. In this paper, the parallel extrusion has been applied to manufacture the round-fin heat sink in the automotive lighting. Numerical simulations on the round-fin heat sink forming using the software DEFORM were carried out. The tooling structure with counterpressure on the heat sink formation was investigated. The results show that the tooling structure with counterpressure is helpful to the formation of round-fin heat sink, which not only ensures the height of each round-fin on the heat sink is uniform but also retards the initiation of flow-through on the reverse side of round-fin. In addition, the experiments of press forging process were conducted to validate the finite element analysis, it is shown that the friction at the punch-blank interface has more significant effect on preventing the initiation of flow-through compared with the friction at the die-blank interface, which implies that the punch-blank interface has more significant effect on the material flow in the formation of round-fin, and the simulation results are in good agreement with the experimental data.

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