Characteristics of Hot Compressed Magnesium Alloy AZ31 with Initial Textures Analyzed by Orientation Mapping

2005 ◽  
Vol 495-497 ◽  
pp. 639-644 ◽  
Author(s):  
Ping Yang ◽  
Li Meng ◽  
Wei Min Mao ◽  
Leng Chen
Keyword(s):  
Dynamic Recrystallization ◽  
Texture Evolution ◽  
Strain Rates ◽  
Plastic Slip ◽  
Relative Contribution ◽  
Orientation Mapping ◽  
Subgrain Rotation ◽  
Ebsd Technique ◽  
Plain Strain ◽  
Band Contrast

Orientation mapping based on EBSD technique was applied to reveal the orientations of new grains and their relationships to the surrounding matrices, to analyze Kikuchi band contrast and the influence of strain rates on local orientation evolution. This information is used to understand the dynamic recrystallization mechanism and the relative contribution of plastic slip versus grain boundary glide or grain rotation related with super-plasticity. For this purpose samples with different initial textures were deformed by (quasi-)plain strain compression at two strain rates. It is suggested that the dynamic recrystallization in this alloy proceeds in continuous way by progressive subgrain rotation. No evident non-basal slip of <a+c> was observed by referring texture evolution in the sample with initial basal texture. A high strain rate promotes more contribution of plastic slip accompanied by fast orientation changes. The fact that groups of grains with very similar orientations in basal oriented samples is discussed in terms of viscous flow.

Dynamic Recrystallization of Zircaloy-4 during Working within the Upper α-Range

2004 ◽  
Vol 467-470 ◽  
pp. 1151-1156 ◽  
Author(s):  
Cédric Chauvy ◽  
Pierre Barbéris ◽  
Frank Montheillet
Keyword(s):  
Dynamic Recrystallization ◽  
Large Strain ◽  
Large Angle ◽  
Rate Sensitivity ◽  
Large Strains ◽  
Strain Rates ◽  
Compression Tests ◽  
Continuous Dynamic Recrystallization ◽  
Ebsd Technique ◽  
Continuous Dynamic

Compression tests were used to simulate simple deformation paths within the upper a-range of Zircaloy-4 (i.e. 500°C-750°C). The mechanical behaviour reveals two different domains : at low temperatures and large strain rates, strain hardening takes place before flow softening, whereas this first stage disappears at lower flow stress levels. Strain rate sensitivity and activation energy were determined for both domains. Dynamic recrystallization was investigated using the Electron BackScattering Diffraction (EBSD) technique. It appears that the mechanism involved here is continuous dynamic recrystallization (CDRX), based on the increasing misorientation of subgrain boundaries and their progressive transformation into large angle boundaries. At low strains (e £ 0.3), CDRX kinetics are similar whatever the deformation conditions, while higher temperatures and lower strain rates promote recrystallization at large strains.

Investigation on Dynamic Recrystallization Behavior in Hot Deformed Superalloy Inconel 718

2007 ◽  
Vol 546-549 ◽  
pp. 1297-1300 ◽  
Author(s):  
Y. Wang ◽  
Wen Zhu Shao ◽  
Liang Zhen ◽  
L. Lin ◽  
Y.X. Cui
Keyword(s):  
Dynamic Recrystallization ◽  
Inconel 718 ◽  
High Angle ◽  
Twin Boundaries ◽  
Continuous Dynamic Recrystallization ◽  
Subgrain Rotation ◽  
Dynamic Recrystallization Behavior ◽  
Ebsd Technique ◽  
Continuous Dynamic ◽  
The Individual

The nucleation and development of dynamic recrystallization (DRX) in hot deformed superalloy Inconel 718 during uniaxial compression were investigated by optical microscopy and electron back-scattered diffraction (EBSD) technique. The results showed that the discontinuous dynamic recrystallization was the predominant DRX mechanism in this alloy. The variations of partial crystallographic orientations led to the individual nucleation inside the deformed grains, which implied the occurrence of local continuous dynamic recrystallization. The progressive subgrain rotation can be confirmed neither near the prior high angle grain boundaries nor within the original grains. It was found that, as the strain increased, the initial twin boundaries were gradually transformed to ordinary mobile high angle boundaries. Meanwhile, the new twin boundaries were formed inside the recrystallized grain necklaces. It was suggested that the characteristics of the twin boundaries evolution with increasing strain were associated with the transformation of initial twin boundaries as well as the generation of new ones, which resulted in the development of DRX.

An OIM Analysis on the Deformation Mechanism in Hot Compressed AZ31 Magnesium Alloy

2005 ◽  
Vol 488-489 ◽  
pp. 633-636 ◽  
Author(s):  
Li Meng ◽  
Ping Yang ◽  
Zude Zhao ◽  
Wei Min Mao
Keyword(s):  
Magnesium Alloy ◽  
Az31 Magnesium Alloy ◽  
Deformation Condition ◽  
Basal Texture ◽  
Slip Mechanism ◽  
Plastic Slip ◽  
Pyramidal Slip ◽  
Orientation Mapping ◽  
Ebsd Technique ◽  
Deformation Strain Rate

Orientation mapping based on EBSD technique was applied to analyze the rules of orientation evolution of grains in AZ31 magnesium alloy. Results show that not only under deformation strain rate of 1×10-2s-1, but under 4×10-4s-1(the superplastic deformation condition), grains in all samples with initial textures rotate gradually to near basal orientation ({0002} || compression plane) at different ways, and basal texture becomes stronger with increasing strain, which indicates plastic slip plays an important role during hot deformation. Otherwise, no evident non-basal pyramidal slip of <a+c> as some studies mentioned was observed in the sample with the initial basal texture, and the basal orientation is kept unchanged during the deformation process, which suggests that basal slip is the uppermost plastic slip mechanism in this sample. In addition, the phenomenon of viscous laminar flow was observed in the sample with initial basal texture.

scholarly journals Investigation into Microstructure Evolution of Co–Ni–Cr–W–Based Superalloy During Hot Deformation

2021 ◽  
Vol 8 ◽  
Author(s):  
Wei Zhang ◽  
Baohong Zhu ◽  
Shuaishuai Wu ◽  
Shutian Tao
Keyword(s):  
Dynamic Recrystallization ◽  
Microstructure Evolution ◽  
Hot Deformation ◽  
Electron Backscatter Diffraction ◽  
Strain Rates ◽  
Compression Tests ◽  
Continuous Dynamic Recrystallization ◽  
Nucleation Mechanisms ◽  
Ebsd Technique ◽  
Continuous Dynamic

Hot compression tests were conducted using a Gleeble 3500 thermomechanical simulator at temperatures ranging from 1,000 to 1,200°C with the strain rate ranging from 0.1 to 10 s−1. Electron backscatter diffraction (EBSD) technique was employed by investigating the microstructure evolution during hot deformation. Microstructure observations reveal that deformation temperatures and strain rates have a significant effect on the DRX process. It is found that the fraction and grain size of DRX increase with the decreasing deformation temperature, along with the increasing high-angle grain boundaries (HAGBs). The fraction of DRX first decreases and then increases with the increase of strain rates. It is noted that there are both the nucleation mechanisms of discontinuous dynamic recrystallization (DDRX) and continuous dynamic recrystallization (CDRX) during the DRX process for Co–Ni–Cr–W–based superalloys. DDRX and CDRX are the primary and subsidiary nucleation mechanisms of DRX, respectively. It is also found that deformation temperatures and strain rates have almost no effect on the primary and subsidiary nucleation mechanisms of DRX. At the temperature above 1,150°C, the complete DRX occurred with the average grain sizes of about 25.32–29.01 μm. The homogeneity and refinement of microstructure can be obtained by selecting the suitable hot deformation parameters.

scholarly journals Hot Rolling of the Twin-Roll Cast and Homogenized Mg-6.8Y-2.5Zn (WZ73) Magnesium Alloy Containing LPSO Structures

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1771
Author(s):  
Madlen Ullmann ◽  
Kristina Kittner ◽  
Ulrich Prahl
Keyword(s):  
Magnesium Alloy ◽  
Dynamic Recrystallization ◽  
Hot Rolling ◽  
Texture Evolution ◽  
Strain Rates ◽  
Zn Content ◽  
Increased Strength ◽  
Twin Roll Cast ◽  
Twin Roll ◽  
Strength And Ductility

In this study, hot rolling trials were conducted on a twin-roll cast and homogenized magnesium alloy Mg-6.8Y-2.5Zn (WZ73). The WZ73 contains long period stacking ordered (LPSO) structures due to the ratio of Y and Zn content. Microstructural and texture evolution depending on the different strain and strain rates were investigated, and the resulting mechanical properties were also considered. Therefore, samples were quenched in water directly after hot rolling. The results revealed that the rolling parameters significantly influence dynamic recrystallization (DRX), while continuous and twin-induced dynamic recrystallization are assumed to be the main DRX mechanisms. It was also found that high strains and strain rates are required to proceed the DRX. The resulting textures revealed that the non-basal slip of <a>-dislocations and <c+a>-dislocations is activated during hot rolling. Hot rolling results in increased strength and ductility compared to the initial twin-roll cast and homogenized state.

Evolution of Microstructure during Hot Deformation of Pearlitic Steel

2013 ◽  
Vol 753 ◽  
pp. 459-462
Author(s):  
Rama Krushna Sabat ◽  
Sajal Hatwal ◽  
Bharath Dixit ◽  
Satyam Suwas
Keyword(s):  
Dynamic Recrystallization ◽  
Hot Deformation ◽  
Texture Evolution ◽  
Pearlitic Steel ◽  
Strain Rates ◽  
Compression Tests ◽  
Flow Curves ◽  
X Ray ◽  
Deformation Response ◽  
Evolution Of Microstructure

Hot deformation of pearlitic steel was carried out to examine the overall deformation response to micro structural and texture evolution. To understand the mechanisms operative during hot deformation, compression tests were carried out at various temperatures in the range 400 - 600o C and strain rates in the range 0.001-10 s-1. The flow curves were analyzed to examine the occurrence of dynamic recrystallization. The evolution of microstructure and texture of hot deformed sample is analysed using EBSD and X-ray texture goniometer respectively.

scholarly journals Modelling and simulation of dynamic recrystallization (DRX) in OFHC copper at very high strain rates

2017 ◽  
Author(s):  
G. Testa ◽  
N. Bonora ◽  
A. Ruggiero ◽  
G. Iannitti ◽  
I. Persechino ◽  
...  
Keyword(s):  
Dynamic Recrystallization ◽  
High Strain ◽  
Modelling And Simulation ◽  
Ofhc Copper ◽  
Strain Rates ◽  
High Strain Rates ◽  
Very High

scholarly journals On the through-process texture evolution assessment in grain oriented Fe-3 wt% Si steel produced by a novel directional inoculation technique

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Snehashish Tripathy ◽  
Sandip Ghosh Chowdhury
Keyword(s):  
Magnetic Field ◽  
Hot Rolling ◽  
Texture Evolution ◽  
Lattice Parameter ◽  
Soft Magnetic ◽  
Oriented Growth ◽  
Inoculation Technique ◽  
Hot Band ◽  
Ebsd Technique ◽  
Cast Microstructure

AbstractA novel directional inoculation technique has been designed to cast thin slab ingots containing Goss (or near Goss) oriented components in the as cast microstructure under the combined effect of oriented nucleation and oriented growth. The same has been targeted so as to retain Goss orientations and simultaneously develop γ fiber components (ranging from {111}<$$1\overline{1}0$$ 1 1 ¯ 0 > to {111}<112>) during hot rolling. The designed scheme of directional inoculation achieved oriented nucleation by the effect of exogenously added soft magnetic inoculants under magnetic field and oriented growth by the effect of fast cooling rates prevailing in the mould. The choice of 65Fe–35Co (wt%) system as soft magnetic inoculants was made taking into account the similarity in crystal structure and lattice parameter. The chemically synthesized inoculants under the effect of external magnetic field during solidification were able to exhibit directional inoculation. Variation in the cast microstructure and microtexture by varying the extent of inoculant addition was studied by EBSD technique. The ingots cast under different conditions were subjected to a designed hot rolling schedule and the through process microstructural and microtextural evolution was assessed. It was observed that fine equiaxed grains with initial cube orientations in the as cast structure could lead to the most desirable microstructural as well as microtextural gradient in the hot band.

Texture and Microstructure Evolution in Friction Stir Welded Cu-Al Sheets Characterized by EBSD

2011 ◽  
Vol 702-703 ◽  
pp. 574-577 ◽  
Author(s):  
Daniel Goran ◽  
G. Ji ◽  
M. N. Avettand-Fènoël ◽  
R. Taillard
Keyword(s):  
Microstructure Evolution ◽  
Electron Backscatter Diffraction ◽  
Texture Evolution ◽  
Weld Interface ◽  
Friction Stir ◽  
Electron Backscatter ◽  
Ebsd Technique ◽  
Backscatter Diffraction

Texture and microstructure of FSW joined Al and Cu sheets were investigated by means of electron backscatter diffraction (EBSD) technique. The analysis has revealed a strong texture evolution on both sides of the weld interface as well as a very complex microstructure. Grains were found to be fully recrystallized on both sides of the weld and with different average diameters at different specific zones of the weld.

Characteristics of Dynamic Recrystallization during Hot Deformation for High Nitrogen Stainless Steels

2012 ◽  
Vol 715-716 ◽  
pp. 115-121
Author(s):  
Hai Wen Luo ◽  
Xu Dong Fang ◽  
Rui Zhen Wang ◽  
Zhan Yin Diao
Keyword(s):  
Dynamic Recrystallization ◽  
Stainless Steels ◽  
Hot Deformation ◽  
Strain Rates ◽  
Peak Strain ◽  
High Nitrogen ◽  
Flow Curves ◽  
Grain Sizes ◽  
Nitrogen Contents ◽  
High Nitrogen Stainless Steel

Dynamic recrystallization was studied for the stainless steels with nitrogen contents of 0.56% to 1.08% during hot deformation at temperatures of 900~1200 with strain rates ranging from 0.003 to 42 s-1. It was found that flow stress could increase remarkably with increasing nitrogen content. Flow curves during the deformation by 0.1~42/s at temperatures of 900~1200°C show a single peak, indicating the occurrence of dynamic recrystallization during deformation. The peak strain seems to decrease with increasing N content, suggesting that higher content of N facilitates dynamic recrystallization. The quenched microstructures were analyzed by optical microscopy, EBSD and TEM. The recrystallized grain sizes on the quenched specimens were measured and its dependence on temperature and strain rate was analyzed. At high temperature, continuously dynamically recrystallized microstructures were observed; whilst at low temperature, necklace-like partially recrystallized microstructures were found. Key words: High nitrogen stainless steel; dynamic recrystallization; stress-strain curves

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