The relationship between dynamic strain aging and serrated flow behaviour in magnesium alloy

2017 ◽  
Vol 97 (6) ◽  
pp. 235-240 ◽  
Author(s):  
W. H. Wang ◽  
D. Wu ◽  
S. S. Shah ◽  
J. H. Ni ◽  
R. S. Chen ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Dynamic Strain Aging ◽  
Strain Aging ◽  
Flow Behaviour ◽  
Dynamic Strain ◽  
Serrated Flow ◽  
The Relationship

Dynamic Strain Aging during Tensile Deformation of Extruded AZ81 Magnesium Alloy

2013 ◽  
Vol 652-654 ◽  
pp. 1937-1941 ◽  
Author(s):  
Si Qian Zhang ◽  
Liang Mao ◽  
Li Jia Chen
Keyword(s):  
Dynamic Strain Aging ◽  
Strain Aging ◽  
Tensile Deformation ◽  
Rate Sensitivity ◽  
Dynamic Strain ◽  
Dynamic Strain Ageing ◽  
Strain Ageing ◽  
Serrated Flow ◽  
Chatelier Effect ◽  
Solute Atoms

Serrated flow has been observed in AZ81 alloy during tensile deformation. The observed static strain ageing effect and negative strain rate sensitivity suggest that the serrated flow is due to interaction between dislocations and solute atoms, know as dynamic strain ageing (DSA). The Portevin-Le Chatelier effect is observed at temperatures between 150oC~200oC and 125oC~200oC. In the microstructure of deformed samples dislocations and twins is observed. It is suggested that the occurrence of the dynamic strain aging is associated with interactions between solute atoms and dislocations.

Dynamic strain aging and serrated flow in MnO

1986 ◽  
Vol 1 (1) ◽  
pp. 124-129 ◽  
Author(s):  
K. C. Goretta ◽  
J. L. Routbort ◽  
T. A. Bloom
Keyword(s):  
Single Crystals ◽  
Yield Stress ◽  
Dynamic Strain Aging ◽  
Strain Aging ◽  
Dynamic Strain ◽  
Local Defect ◽  
Serrated Flow ◽  
Partial Pressures ◽  
Effects Of Aging ◽  
Segregation Of Impurities

The effects of aging on the upper yield stress τup and serrated flow have been studied in MnO single crystals at 900 °C for oxygen partial pressures ρO2 of 10−11 and 10−7 Pa. Aging initially increases τup as a consequence of segregation of aliovalent impurities to dislocations for both ρO2 values. For long aging times and ρO2 = 10-11 Pa, serrated flow accompanied by solute softening is observed. The data fit predictions of a Portevin-Le Chatelier model for serrations, but with impurity atmospheres causing softening instead of hardening. This is believed to result from changes in local defect equilibria caused by segregation of impurities with valences greater than two to dislocations.

Dynamic Strain Aging Induced by Cyclic Deformation in Two Magnesium Alloys

2011 ◽  
Vol 299-300 ◽  
pp. 90-93
Author(s):  
Li Jia Chen ◽  
Jia Li ◽  
Feng Li ◽  
Xin Wang
Keyword(s):  
Hysteresis Loop ◽  
Magnesium Alloys ◽  
Dynamic Strain Aging ◽  
Cyclic Deformation ◽  
Strain Aging ◽  
Solution Treatment ◽  
Control Mode ◽  
Dynamic Strain ◽  
Stress Strain ◽  
Serrated Flow

Cyclic deformation for two magnesium alloys AZ91 and AM50 with different processing status has been performed under total strain amplitude control mode and at room temperature. A serrated flow can be observed in both tensile and compressive directions of the stress-strain hysteresis loop for as-extruded AZ91 and AM50 magnesium alloys. It means that the so-called dynamic strain aging occurs during cyclic deformation. In addition, the dynamic strain aging phenomenon can also be observed in two extruded magnesium alloys subjected to aging treatment as well as the AZ91 alloy subjected to solution treatment. However, the dynamic strain aging seems not to take place in the extruded AM50 alloy subjected to solution treatment because there exists no significant serrated flow behavior in either compressive or tensile direction of the stress-strain hysteresis loop. It is suggested that the occurrence of the dynamic strain aging is associated with collective behavior of many mobile dislocations as well as interactions between solute atoms and dislocations.

Dynamic strain aging and serrated flow behavior of Cr-Ti-B low carbon steel during warm deformation

2021 ◽  
Vol 172 ◽  
pp. 110828
Author(s):  
Ankang Huang ◽  
Zhigang Wang ◽  
Xin Liu ◽  
Qiangqiang Yuan ◽  
Jieyun Ye ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Dynamic Strain Aging ◽  
Strain Aging ◽  
Flow Behavior ◽  
Low Carbon Steel ◽  
Dynamic Strain ◽  
Low Carbon ◽  
Warm Deformation ◽  
Serrated Flow

Modeling serrated flow of SS 316L under dynamic strain aging effect

Sadhana ◽  
2020 ◽  
Vol 45 (1) ◽  
Author(s):  
Siddhartha Patra ◽  
Sankar Dhar ◽  
Sanjib Kumar Acharyya
Keyword(s):  
Dynamic Strain Aging ◽  
Strain Aging ◽  
Aging Effect ◽  
Dynamic Strain ◽  
Serrated Flow

Study on Dynamic Strain Aging Phenomenon of AZ91D Magnesium Alloy

2012 ◽  
Vol 472-475 ◽  
pp. 2962-2965 ◽  
Author(s):  
Na Lin ◽  
Kai Huai Yang ◽  
Shao Feng Zeng ◽  
Wen Zhe Chen
Keyword(s):  
Activation Energy ◽  
Solid Solution ◽  
Magnesium Alloy ◽  
Dynamic Strain Aging ◽  
Strain Aging ◽  
Solution Treatment ◽  
Dynamic Strain ◽  
Strain Rates ◽  
Az91d Magnesium Alloy ◽  
Solute Atoms

Tensile experiment of AZ91D magnesium alloy was carried out and serrated flow was apparent throughout the deformation history. Dynamic strain aging (DSA) occurs when the AZ91D magnesium alloy treated by solid solution treatment has been deformed at a set range of strain rates (1.11×10-4 s-1 to1.67×10-3 s-1) and a certain range temperatures (248 K to 423 K). The critical plastic strain εc was observed to increase with increasing strain rates but decrease with increasing temperature. The diffusing activation energy of solute atoms during the DSA occurring in AZ91D magnesium alloy is 140.8 kJ/mol by calculating, which is correspondence match with the diffusing activation energy of Al solute atoms in Mg matrix. Therefore, the micro-mechanism of DSA in the alloy is believed that the Al atoms in solid solution gather around dislocations to form Cottrell solute atmospheres by vacant diffusion and then pin the moving dislocations.

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