Effects of Anisotropy on the Microstructural Characteristics and Mechanical Behavior of Shock-Loaded of AZ31 Alloy

2011 ◽  
Vol 284-286 ◽  
pp. 1537-1541 ◽  
Author(s):  
Min Hao ◽  
Fan Zhang ◽  
Cheng Wen Tan ◽  
Tie Jian Su ◽  
Xiao Dong Yu
Keyword(s):  
Mechanical Behavior ◽  
Strain Hardening ◽  
Electron Backscatter Diffraction ◽  
Az31 Alloy ◽  
Peak Strain ◽  
Compression Tests ◽  
Microstructural Characteristics ◽  
Post Shock ◽  
Backscatter Diffraction ◽  
Strain Hardening Rate

Effects of anisotropy on the microstructural characteristics and mechanical behavior of shock loaded of AZ31 magnesium alloy have been investigated. Using electron backscatter diffraction, tension twinning was observed in both shock loading directions along the normal (ND) and rolling directions (RD). Compression tests were carried out along ND and RD in both as-received and post-shock conditions. It indicated that the RD samples show a more notable hardening behavior compared to the as-received conditions. Moreover, it is postulated here that detwinningresults in a drop of strain-hardening rate for the ND samples under post shock reload conditions and tension twinning formed during the shock wave loading process leads to a significant moving left of the peak strain hardening rate for the RD samples under post shock reload conditions.

scholarly journals Decoupling the Impacts of Strain Rate and Temperature on TRIP in a Q&P Steel

JOM ◽  
2022 ◽  
Author(s):  
Christopher B. Finfrock ◽  
Diptak Bhattacharya ◽  
Brady N. L. McBride ◽  
Trevor J. Ballard ◽  
Amy J. Clarke ◽  
...  
Keyword(s):  
Martensitic Transformation ◽  
Strain Rate ◽  
Strain Hardening ◽  
Electron Backscatter Diffraction ◽  
Dislocation Slip ◽  
Transformation Induced Plasticity ◽  
High Strain Rate Deformation ◽  
The Individual ◽  
Backscatter Diffraction ◽  
Strain Hardening Rate

AbstractThe individual effects of strain rate and temperature on the strain hardening rate of a quenched and partitioned steel have been examined. During quasistatic tests, resistive heating was used to simulate the deformation-induced heating that occurs during high-strain-rate deformation, while the deformation-induced martensitic transformation was tracked by a combination of x-ray and electron backscatter diffraction. Unique work hardening rates under various thermal–mechanical conditions are discussed, based on the balance between the concurrent dislocation slip and transformation-induced plasticity deformation mechanisms. The diffraction and strain hardening data suggest that the imposed strain rate and temperature exhibited dissonant influences on the martensitic phase transformation. Increasing the strain rate appeared to enhance the martensitic transformation, while increasing the temperature suppressed the martensitic transformation.

Comparison of Workability of ZK60A Alloy Depending on Casting Methods

2012 ◽  
Vol 630 ◽  
pp. 35-40
Author(s):  
K.H. Jung ◽  
B. Ahn ◽  
S. Lee ◽  
D.S. Choi ◽  
Y.S. Lee ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Continuous Casting ◽  
Elevated Temperatures ◽  
Electron Backscatter Diffraction ◽  
Die Casting ◽  
Inspection System ◽  
Compression Tests ◽  
X Ray ◽  
Electron Backscatter ◽  
Backscatter Diffraction

In this research, the effect of casting methods on the workability of magnesium alloy ZK60A was investigated by comparing two different billets, fabricated by semi-continuous casting and die casting. To determine the workability of the materials, uniaxial compression tests were conducted at different elevated temperatures and strain rate of 0.01/s. In addition, the X-ray inspection system and electron backscatter diffraction (EBSD) were employed to compare their internal defects and microstructures, respectively. The workability of ZK60A depending on the casting methods is discussed based on the obtained experimental results.

Microband-To-Microshear Band Transition near Grain Boundaries in BCC Steel

2007 ◽  
Vol 558-559 ◽  
pp. 873-878 ◽  
Author(s):  
Dorothée Dorner ◽  
Yoshitaka Adachi ◽  
Kaneaki Tsuzaki
Keyword(s):  
Grain Boundary ◽  
Crystal Orientation ◽  
Electron Backscatter Diffraction ◽  
Early Stage ◽  
Compression Tests ◽  
Grain Boundary Characteristics ◽  
Band Transition ◽  
Boundary Characteristics ◽  
Backscatter Diffraction ◽  
Initial Crystal

Compression tests were performed on Fe-3%Si specimens with few grains. The deformation microstructure and microtexture were investigated by electron backscatter diffraction (EBSD) and related to the initial crystal orientation and grain boundary characteristics. Groups of microbands were found that are characterised by a periodic change in crystal orientation, shear at the grain boundary, and the formation of new grains. It is supposed that these microband groups represent an early stage of microshear band development.

Dynamic Recrystallization of 7055 Aluminum Alloy during Hot Deformation

2010 ◽  
Vol 650 ◽  
pp. 295-301 ◽  
Author(s):  
Liang Ming Yan ◽  
Jian Shen ◽  
Ju Peng Li ◽  
Zhou Bing Li ◽  
Zhen Lei Tang
Keyword(s):  
Dynamic Recrystallization ◽  
Grain Boundaries ◽  
Electron Backscatter Diffraction ◽  
Local Area ◽  
Deformation Condition ◽  
Compression Tests ◽  
Nucleation Mechanisms ◽  
Z Value ◽  
7055 Aluminum Alloy ◽  
Backscatter Diffraction

Compression tests were performed at temperatures from 350 to 450 °C with different strain rates of 1.0×10−2 and 1.0×10−1 s−1. The microstructures of deformed samples were investigated by electron backscatter diffraction (EBSD). Microstructure observations indicated that under present deformation conditions, fraction of new grains increases with the Z value. It was found that different nucleation mechanisms for DRX were operated in hot deformed 7055 alloy, which was closely related to deformation condition. DRX nucleation and development were discussed in consideration of bulging of original grain boundaries and occasional subgrain rotation near the grain boundaries. Discontinuous dynamic recrystallization (DDRX) which occurred in a local area was also proved to be a nucleation mechanism at higher Z value for 7055 alloy.

scholarly journals Structure / Property (Constitutive and Dynamic Strength / Damage) Behavior of Additively Manufactured Tantalum

2018 ◽  
Vol 183 ◽  
pp. 03002
Author(s):  
George.T. Gray ◽  
Veronica Livescu ◽  
Cameron Knapp ◽  
David R. Jones ◽  
Saryu Fensin ◽  
...  
Keyword(s):  
Mechanical Behavior ◽  
Damage Evolution ◽  
Electron Backscatter Diffraction ◽  
Dynamic Strength ◽  
Functional Requirements ◽  
Structure Property ◽  
Powder Bed ◽  
Static Mechanical ◽  
Backscatter Diffraction ◽  
Dynamic Damage

For Certification and qualification of an engineering component generally involves meeting engineering and physics requirements tied to its functional requirements. In this paper, the results of a study quantifying the microstructure, mechanical behavior, and the dynamic damage evolution of Tantalum (Ta) fabricated using an EOS laser-powder-bed machine are presented. The microstructure and quasi-static mechanical behavior of the AM-Ta is detailed and compared / contrasted to wrought Ta. The dynamic damage evolution and failure response of the AM-Ta material, as well as wrought Ta, was probed using flyer-plate impact driven spallation experiments. The differences in the spallation response between the AM and wrought Ta were measured using in-situ velocimetry as well as post-mortem quantification of damage in “soft-recovered” samples. The damage evolution of the AM and wrought Ta were characterized using both optical metallography and electron-backscatter diffraction.

Grain Rotation during Twin-Detwin Deformation of Mg AZ31 Alloy Using In Situ XRD and EBSD

2019 ◽  
Vol 793 ◽  
pp. 17-22
Author(s):  
Hong Jia Zhang ◽  
Enrico Salvati ◽  
Chrysanthi Papadaki ◽  
Kai Soon Fong ◽  
Xu Song ◽  
...  
Keyword(s):  
Electron Backscatter Diffraction ◽  
Az31 Alloy ◽  
High Energy ◽  
Intensity Change ◽  
X Ray Diffraction ◽  
Grain Rotation ◽  
Backscatter Diffraction ◽  
Tension Loading ◽  
Good Agreement

To investigate grain rotation caused by twinning-detwinning during plastic deformation, experiments using synchrotron high energy X-ray Diffraction (XRD) and Electron Backscatter Diffraction (EBSD) are carried out under in situ compression-tension loading. Comparison between the XRD and EBSD data confirms that the intensity change of diffraction rings in XRD experiment is caused by twining and detwinning. A good agreement of twin fraction values obtained from XRD and EBSD is achieved. This demonstrates that the grains and texture are homogeneously distributed along the normal direction of the sample. In the meantime, it is observed that detwinning can only be activated in a large quantity when the loading reverses into tension from compression in the first loading stage.

Workability of ZK60A Alloy Depending on Microstructure

2012 ◽  
Vol 217-219 ◽  
pp. 373-376 ◽  
Author(s):  
K.H. Jung ◽  
Yong Bae Kim ◽  
Byung Min Ahn ◽  
Sang Mok Lee ◽  
Jong Sup Lee ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Uniaxial Compression ◽  
Microstructural Evolution ◽  
Elevated Temperatures ◽  
Electron Backscatter Diffraction ◽  
Strain Rates ◽  
Compression Tests ◽  
Electron Backscatter ◽  
Before And After ◽  
Backscatter Diffraction

In this study, the variation of workability of semi-continuously casted and extruded ZK60A magnesium alloy was investigated. To determine the deformation capability of two different billets, uniaxial compression tests were conducted at elevated temperatures and two different strain rates. In addition, the microstructural evolution was investigated using electron backscatter diffraction (EBSD) to compare the microstructure before and after the extrusion. The formability of ZK60A depending on the microstructure is discussed based on the experimental results obtained in this study, and is compared with earlier research in the literature.

Impact of Peak Shock Stress on the Microstructure and Reloaded Mechanical Behavior of AZ31 Magnesium Alloy

2014 ◽  
Vol 788 ◽  
pp. 64-67
Author(s):  
Min Hao ◽  
Cheng Wen Tan ◽  
Xu Dong Wang ◽  
Wei Wei He ◽  
Bin Yang
Keyword(s):  
Mechanical Behavior ◽  
Mechanical Response ◽  
Az31 Alloy ◽  
Strengthening Effect ◽  
Specific Strength ◽  
Transmission Electron ◽  
Recovery Techniques ◽  
Post Shock ◽  
Peak Shock ◽  
Hot Rolled

Magnesium alloys can be utilized as potential aerospace materials due to their low density, high specific strength, good vibration and shock absorption ability. This paper deals with the mechanical behavior of hot-rolled AZ31 alloy that was shock-deformed to 2.3 and 3.3 GPa. The post shock microstructure and mechanical response have been determined via full one-dimensional recovery techniques. The microstructure of deformed sample was characterized by the transmission electron microscopy (TEM) and electron back scattered diffraction (EBSD) techniques. All the shock-deformed materials showed shock-strengthening effect that was greater at higher shock pressure. The reload yield stress of the shock-deformed 2.3 GPa sample was determined to be 238 MPa while 264 MPa for the sample which shock-deformed at 3.3 GPa. It was postulated that the shock-strengthening is ascribed to a greater dislocation density and the formation of deformation twins.

Critical Condition of Dynamic Recrystallization of IN690 Using Strain Hardening Rate

2011 ◽  
Vol 148-149 ◽  
pp. 1141-1144
Author(s):  
Zhong Tang Wang ◽  
Yong Gang Deng ◽  
Shi Hong Zhang ◽  
Ming Cheng
Keyword(s):  
Dynamic Recrystallization ◽  
Strain Hardening ◽  
Critical Strain ◽  
Critical Conditions ◽  
Peak Strain ◽  
Deformation Properties ◽  
Strain Model ◽  
Strain Hardening Rate ◽  
Super Alloy ◽  
Good Agreement

It had been studied that thermal deformation properties of super-alloy Inconel690(IN690) by thermal simulation on Gleeble 3800 Simulator, which the ranges of temperature was 1000～1200°Cand strain rates was 1.0～80/s. According to the experiment data, the critical conditions of super-alloy Inconel690 had been researched by strain hardening rate. Zener-Hollomn parameters (Z) had been introduced into establish the critical conditions of dynamic recrystallization, such as critical strain and critical stress and peak strain. The results showed that the critical strain model which established using strain hardening rate was in good agreement with that of Sellar’s model.

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