Dynamic Recrystallization and Microstructure Evolution in AZ31 Magnesium Alloy during Thermomechanical Processing

Author(s):  
Guang Jie Huang ◽  
Ling Yun Wang ◽  
Guang Sheng Huang ◽  
Fu Sheng Pan
2005 ◽  
Vol 488-489 ◽  
pp. 215-218 ◽  
Author(s):  
Guang Jie Huang ◽  
Ling Yun Wang ◽  
Guang Sheng Huang ◽  
Fu Sheng Pan

The deformation behavior of AZ31 magnesium alloy has been investigated by isothermal compression at temperatures between 573-723K and at constant strain rates ranging from 10-3 -1s-1. It is shown that the form of flow stress curves is very sensitive to temperature and strain rate. In the experimental domain studied, the flow stresses are modeled using a power law with an average activation energy of 145.16 kJ/mol, and dynamic recrystallization (DRX) occurs. The critical strain for DRX is determined by analysis of flow stress curves. The ratio of the critical strain to the peak strain falls in the range of 0.4-0.5. At low temperatures and high strai rates, the deformation become macroscopically inhomogeneous, and the fracture of the specimens is accompanied by shear banding. Grain refinement resulting from DRX is less effective at high temperatures due to rapid grain growth. It is also shown that there is no difference between peak stress and stable state stress at high temperatures and lower strain rates, presenting the feature of continuous dynamic recrystallization (CDRX).


2010 ◽  
Vol 654-656 ◽  
pp. 727-730 ◽  
Author(s):  
Koji Aoyama ◽  
Mitsuaki Furui ◽  
Susumu Ikeno

It had been already reported that the resistance of compression at warm condition can be decreased by the preliminary torsion working at AZ31B magnesium alloy. In the present study, it was found that the dynamic recrystallization occured during warm working by torsion. Dynamic recrystallization was slightly seen in the fractured edge of the bar at a rotation speed of 1rpm at temperature 573K and 623K. The amount of torsion to fracture was increased with increasing of deformation temperature. Remarkable dynamic recrystallization could be seen in the center of bar at the rotation speed of 1rpm at temperature of 673K.


2013 ◽  
Vol 395-396 ◽  
pp. 218-222 ◽  
Author(s):  
Chen Yang Xu ◽  
Fu Xiang Chu ◽  
Xiao Ling Xu ◽  
Hao Chen ◽  
Fang Gao

Microstructure evolution characteristics and the influence of the intial grain size on the dynamic recrystallization of AZ31 were investigated by rolling at deformation temperature of 280 °C, 30% reduction and strain rate of 5.6s-1. The results indicate that under the present deformation condition, when the grain size is 6.2μm the dynamic recrystallization does not occur , twinning dynamic recrystallization (TDRX) occurs when the original grain size are of 7.9μm and 12.7μm, when the original grain size is 21.1μm rotating dynamic recrystallization (RDRX) occurs.


2014 ◽  
Vol 609-610 ◽  
pp. 495-499
Author(s):  
Guo Cheng Ren ◽  
Xiao Juan Lin ◽  
Shu Bo Xu

The microstructure and material properties of AZ31 magnesium alloy are very sensitive to process parameters, which directly determine the service properties. To explore and understand the deformation behavior and the optimization of the deformation process, the microstructure evolution during equal channel angular pressing was predicted by using the DEFORM-3D software package at different temperature. To verify the finite element simulation results, the microstructure across the transverse direction of the billet was measured. The results show that the effects strain and deformation temperatures on the microstructure evolution of AZ31 magnesium during ECAP process are significant, and a good agreement between the predicted and experimental results was obtained, which confirmed that the derived dynamic recrystallization mathematical models can be successfully incorporated into the finite element model to predict the microstructure evolution of ECAP process for AZ31 magnesium.


2007 ◽  
Vol 344 ◽  
pp. 31-38 ◽  
Author(s):  
Archimede Forcellese ◽  
Mohamad El Mehtedi ◽  
M. Simoncini ◽  
S. Spigarelli

The formability of AZ31 magnesium alloy sheets has been investigated in the temperature range varying from 200 to 300°C. Forming limit diagrams have been obtained by performing Nakazima-based tests. The different straining conditions have been investigated using sheet blanks with several length to width ratios. The forming limit curves have been related to the microstructural evolution occurring during deformation. The forming limit diagrams have shown a remarkable increase in formability with temperature that could be related to the occurrence of full dynamic recrystallization at 300°C.


2013 ◽  
Vol 50 ◽  
pp. 667-673 ◽  
Author(s):  
Hua Zhang ◽  
Guangsheng Huang ◽  
Hans Jørgen Roven ◽  
Lifei Wang ◽  
Fusheng Pan

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