Influnce of Grain Size on Dynamic Recrystallization of AZ31 Magnesium Alloy Rolling Sheet

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 1015 ◽  
pp. 203-206
Author(s):  
Quan Li ◽  
Jin Yang ◽  
Wen Jun Liu ◽  
Su Qin Luo ◽  
Ren Ju Cheng ◽  
...  

Hot compression tests of AZ61 magnesium alloy were performed on gleeble1500D at strain rate ranged in 0.01~1s-1 and deformation temperature 350~400°C.The results show that the flow stress and microstructures strongly depend on the deformation temperature and the strain rate. When the temperature was reduced and the strain rate was enhanced, the area after dynamic recrystallization was enhanced, and the average dynamically recrystallied grain size reduce. But the dynamically recrystallied grain size was not well-proportioned. In this paper the 350°C×1s-1 was suggested.


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.


2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Zhongtang Wang ◽  
Lingyi Wang ◽  
Lizhi Liu

Microstructure evolution of AZ31 magnesium alloy in annealing process had been investigated by experiment study at heating temperature range of 150°C–450°C and holding time range of 15 min–60 min. The effects of heating temperature and holding time on grain growth had been analyzed. The results presented that the grain size tends to grow up with the increase of holding time at a certain temperature. At a certain holding time, the grain size increased firstly and then decreased at the heating temperature range of 150–250°C. And when heating temperature is higher than 250°C, the grain grows up gradually with the increase of heating temperature. The grain growth model of AZ31 Mg alloy has been established by regression based on the experimental data at temperature of 250–450°C, and the relative error between model calculation results and experimental results is less than 19.07%. Activation energy of grain growth of AZ31 magnesium alloy had been determined.


Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2019
Author(s):  
Wenke Wang ◽  
Qing Miao ◽  
Xuemin Chen ◽  
Yang Yu ◽  
Wencong Zhang ◽  
...  

In this work, the influence of various rolling temperatures and thickness reductions on the dynamic recrystallization (DRX) behavior of AZ31 magnesium alloy sheets was investigated. Meanwhile, the texture variation controlled by DRX behavior was analyzed. Results suggested that, with the help of DRX behavior, reasonable matching of rolling temperature and thickness reduction could effectively refine the grain size and improve the microstructure homogeneity. Using the grain refinement and microstructure homogeneity as the reference, the critical rolling process parameters were 400 °C—30%, 300 °C—30%, and 250 °C—40% in the present work. In terms of basal texture variation, the occurrence of twins produced the largest maximum texture intensity. However, for the sheets with DRX behavior, the maximum texture intensity decreased sharply, but would steadily increase with the growth of DRXed grain. Additionally, for DRXed grains, the <11-20>//RD (RD: rolling direction) grains would gradually annex the <10-10>//RD grains with the growth of DRXed grains, which finally made their texture component become the dominant texture state. However, when the deformation continued, the <10-10> in DRXed grains would rotate toward the RD again. Weighted by the fracture elongation of AZ31 magnesium alloy sheet, the critical thickness reductions were 30–40% under the rolling temperature of 400 °C.


2018 ◽  
Vol 228 ◽  
pp. 04006
Author(s):  
Jing Lu ◽  
Gaosheng Fu ◽  
Zhimeng Ren ◽  
Jie Liu ◽  
Huan Hao

The thermal deformation microstructure of continuous extrusion copper bus bar was observed and analyzed in the temperature range from 200°C to 700°C and at strain rate from 0.01s-1 to 10.0s-1 and at deformation amount from30% to 90% on Gleeble1500 test machine. The experiment results show that the higher the temperature, the lower the strain rate, the more dynamic recrystallization occurred. At the same strain rate, the copper bus bar changes from raw material of as-cast organization to recrystallization grain gradually as the deformation temperature and deformation degree increase, and the recrystallization grain size grows older with the rise of temperature. At the same deformation temperature, the temperature of recrystallization nucleation decreases while the strain rate increases. At low strain rate (0.01~1.0s-1), the dynamic recrystallization occurred at 500°C. While at high strain rate (10.0s-1), the recrystallization nucleation is advanced and it is already completed at 500°C. The Z parameters can be used to express the effect of deformation temperature and strain rate on the average grain size D, and the prediction model of the thermal deformation microstructure is obtained as follows: lnD=4.822-0.018lnZ


2018 ◽  
Vol 37 (7) ◽  
pp. 635-647 ◽  
Author(s):  
Le Li ◽  
Li-yong Wang

AbstractIn order to study dynamic recrystallization behavior of the as-extruded 3Cr20Ni10W2 under isothermal compression conditions, a cellular automaton (CA) model was applied to simulate hot compression. Analysis on the strain–stress curves indicates that dynamic recrystallization is the main softening mechanism for the 3Cr20Ni10W2 when the deformation occurred in the temperature range of 1203–1303 K with an interval of 50 K and strain rate range of 0.01–10 s−1. The deformation temperature and strain rate have a significant influence on the dynamically recrystallized grain size. Subsequently, a CA model is established to simulate the dynamic recrystallization behaviors of the studied alloy. The simulated results show that the mean grain size increases with the increased deformation temperature and decreases with the increased strain rate, which is consistent with the experimental result. In addition, the average absolute relative error, which is 13.14%, indicates that the process of the dynamic recrystallization and the dynamically recrystallized grain size can be well predicted by the present CA model.


2008 ◽  
Vol 575-578 ◽  
pp. 222-225
Author(s):  
Xing Zhang ◽  
Zhi Min Zhang ◽  
Bao Cheng Li

Thermal compression tests of AZ61 magnesium alloy was performed at deformation temperature 150-400°C and strain rates ranged from 0.01s-1 to 10s-1, and the microstructure were observed for deformation specimens. The result shows that dynamic recrystallization (DRX) was happened under the center warm deformation condition for AZ61 alloy. The values of stress peak decrease when the deformation temperature increase, the grain size grows up at the same time. On the other hand, the critical strain increase and the grain size get smaller with the strain ratio increasing. Therefore temperature and strain ratio can make a great effect on the microstructure and mechanical properties of AZ61 alloy, but temperature is a more important factor.


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