Microstructure and Texture Evolution during Recrystallization of a Fe-Mn-C Alloy

2013 ◽  
Vol 753 ◽  
pp. 177-180 ◽  
Author(s):  
Fa Yun Lu ◽  
Christian Haase ◽  
Luis Antonio Barrales-Mora ◽  
Dmitri A. Molodov ◽  
Ping Yang
Keyword(s):  
Grain Boundaries ◽  
Texture Evolution ◽  
Shear Bands ◽  
Strong Impact ◽  
Triple Junctions ◽  
Low Intensity ◽  
Nucleation Sites ◽  
Annealing Twins ◽  
Preferential Nucleation ◽  
Cold Rolled

Microstructure and texture evolution of a 60% cold-rolled Fe-22.3Mn-0.3C alloy during annealing at 550°C were studied. Shear bands, triple junctions and grain boundaries were found to be the preferential nucleation sites. The orientations of the nuclei from these sites were found to be mainly random, but also partly located in α-(//ND) and γ-fibers (//ND). After annealing, fine recrystallized grains formed with abundant annealing twins which had a strong impact on the texture development. The final texture was of low intensity and revealed a weak α-fiber.

Recrystallization Kinetics and Texture Evolution during Annealing of Cold Rolled Fe-Mn-C Alloy

2012 ◽  
Vol 715-716 ◽  
pp. 568-573 ◽  
Author(s):  
Ya Ping Lü ◽  
Dmitri A. Molodov ◽  
Günter Gottstein
Keyword(s):  
Texture Evolution ◽  
Shear Bands ◽  
X Ray Diffraction ◽  
X Ray ◽  
Recrystallization Kinetics ◽  
Nucleation Sites ◽  
Preferential Nucleation ◽  
Cold Rolled ◽  
Mechanical Twins

The recrystallization behavior of 50% cold rolled Fe-22%Mn-0.376%C alloy during annealing at 560°C, 630°C and 700°C was investigated. Microhardness tests were applied for characterization of the recrystallization kinetics, X-ray diffraction and EBSD measurements were utilized to characterize the crystallographic texture and the grain microstructure. The obtained experimental data were evaluated in terms of the JMAK model. The obtained values of the Avrami exponent varied in the range between 0.70 and 1.37. The inhomogeneous grain microstructure after recrystallization is interpreted in terms of non-randomly distributed nuclei. Shear bands, lamellar lines intersecting with mechanical twins and grain boundaries with localized high misorientation gradients were identified to be preferential nucleation sites. No pronounced texture was observed after annealing at 630°C.

Microstructure and Texture Evolution in Nickel during Accumulative Roll Bonding

2016 ◽  
Vol 879 ◽  
pp. 454-458 ◽  
Author(s):  
Jia Qi Duan ◽  
Md Zakaria Quadir ◽  
Michael Ferry
Keyword(s):  
Grain Boundaries ◽  
Accumulative Roll Bonding ◽  
Texture Evolution ◽  
Shear Bands ◽  
Rolling Direction ◽  
Sample Surface ◽  
Deformation Texture ◽  
Roll Bonding ◽  
Equiaxed Grains ◽  
Electron Back Scattered Diffraction

Microstructure and texture evolution of commercially pure Ni processed by accumulative roll-bonding (ARB) up to eight cycles were studied using electron back scattered diffraction (EBSD). During ARB processing, the original coarse equiaxed grains were gradually transformed into refined lamellar grains along the rolling direction (RD). Shear bands started forming after three cycles. The fraction of low angle grain boundaries (LAGBs) increased after the first and second cycle because of orientation spreading within the original grains. However, their fraction decreased with the evolution of high angle grain boundaries (HAGBs) during subsequent deformations, until saturation was reached after six cycles. Overall, the typical deformation texture components (S, Copper and Brass) were enhanced up to six ARB cycles and then only Copper was further strengthened. At higher cycles a higher Copper concentration was found near sample surface than the interiors due to a high frictional shear of ARB processing.

An Sem/Ebsd Study of Shear Bands Formation in Al-0.23%wt.Zr Alloy Deformed in Plane Strain Compression / Krystalograficzne Aspekty Formowania Sie Pasm Scinania W Stopie Al-0.23%Wag.Zr Odkształcanym W Próbie Nieswobodnego Sciskania

2013 ◽  
Vol 58 (1) ◽  
pp. 145-150 ◽  
Author(s):  
H. Paul ◽  
P. Uliasz ◽  
M. Miszczyk ◽  
W. Skuza ◽  
T. Knych
Keyword(s):  
Crystal Lattice ◽  
Grain Boundaries ◽  
Texture Evolution ◽  
Shear Bands ◽  
Shear Direction ◽  
Face Centered Cubic ◽  
Electron Backscattered Diffraction ◽  
Cubic Metals ◽  
Slip Planes ◽  
Face Centered

The crystal lattice rotations induced by shear bands formation have been examined in order to investigate the influence of grain boundaries on slip propagation and the resulting texture evolution. The issue was analysed on Al-0.23wt.%Zr alloy as a representative of face centered cubic metals with medium-to-high stacking fault energy. After solidification, the microstructure of the alloy was composed of flat, twin-oriented, large grains. The samples were cut-off from the as-cast ingot in such a way that the twinning planes were situated almost parallel to the compression plane. The samples were then deformed at 77K in channel-die up to strains of 0.69. To correlate the substructure with the slip patterns, the deformed specimens were examined by SEM equipped with a field emission gun and electron backscattered diffraction facilities. Microtexture measurements showed that strictly defined crystal lattice re-orientations occurred in the sample volumes situated within the area of the broad macroscopic shear bands (MSB), although the grains initially had quite different crystallographic orientations. Independently of the grain orientation, their crystal lattice rotated in such a way that one of the f111g slip planes became nearly parallel to the plane of maximum shear. This facilitates the slip propagation across the grain boundaries along the shear direction without any visible variation in the slip plane. A natural consequence of this rotation is the formation of specific MSB microtextures which facilitates slip propagation across grain boundaries.

Deciphering the role of multiple generations of annealing twins on texture evolution in cold-rolled high entropy alloys during annealing

2021 ◽  
Vol 205 ◽  
pp. 114221
Author(s):  
Lalit Kaushik ◽  
Jaiveer Singh ◽  
Joo-Hee Kang ◽  
Yoon Seok Ko ◽  
Dong-Ik Kim ◽  
...  
Keyword(s):  
Texture Evolution ◽  
High Entropy Alloys ◽  
High Entropy ◽  
Multiple Generations ◽  
Annealing Twins ◽  
Cold Rolled

scholarly journals Effect of Shear Bands Induced by Asymmetric Rolling on Microstructure and Texture Evolution of Non-Oriented 3.3% Si Steel

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4696
Author(s):  
Zhiyong Fang ◽  
Yanhui Guo ◽  
Bin Fu ◽  
Liqun Wei ◽  
Jun Chen ◽  
...  
Keyword(s):  
Surface Layer ◽  
Thermal Energy ◽  
Annealing Temperature ◽  
Texture Evolution ◽  
Shear Bands ◽  
Subsequent Annealing ◽  
Asymmetric Rolling ◽  
Nucleation Sites ◽  
Different Temperatures ◽  
Complete Recrystallization

In the present work, the microstructure and texture of non-oriented 3.3% Si steel processed by asymmetric rolling (ASR) and subsequent annealing at different temperatures were compared with those obtained when using traditional symmetric rolling (SR). This work aims to reveal the effect of shear bands introduced by the ASR on the microstructure and texture evolution. The ASR sample reaches a recrystallization fraction of 62% at an annealing temperature of 650 °C, which is 32% higher than that of the SR sample annealed at the same temperature. This can be attributed to the abundant shear bands introduced by the ASR, which serve as the heterogeneous nucleation sites for the recrystallized grains. When increasing the annealing temperature to 750 °C, complete recrystallization could be observed in both asymmetric- and symmetric-rolled samples. When using an annealing temperature of 650 °C, the γ-oriented grains were dominant in the surface layer, while strong Goss-oriented grains could be observed in the center in the ASR sample. This is due to the fragmented small subgrains with different orientations in the surface layer inhibiting the nucleation of Goss- and cube-oriented grains during the annealing. In contrast, numerous Goss- and cube-oriented grains were formed in the surface layer after complete recrystallization when the ASR sample was annealed at a temperature of 750 °C. This may be related to the higher thermal energy, which benefits the nucleation of the Goss- and cube-oriented grains. In addition, ASR significantly increased the strength of η-fiber after complete recrystallization when compared with SR. This work might be helpful to design the rolling and the subsequent annealing processes.

Shear Banding in Polycrystalline Aluminium and Copper Pre-Deformed by ECAP and Subsequently Plane Strain Compressed

2016 ◽  
Vol 716 ◽  
pp. 240-247
Author(s):  
Henryk Paul ◽  
Magdalena M. Miszczyk
Keyword(s):  
Crystal Lattice ◽  
Grain Boundaries ◽  
Texture Evolution ◽  
Shear Banding ◽  
Shear Bands ◽  
Shear Plane ◽  
Lattice Rotation ◽  
Pure Aluminium ◽  
Electron Backscattered Diffraction ◽  
Angular Pressing

The microstructure and texture evolution in commercially pure aluminium (AA1050 alloy) and copper have been characterized after change in strain path to elucidate the mechanisms of shear bands (SBs) formation and propagation across grain boundaries. Samples were pre-deformed in equal channel angular pressing (ECAP) and further compressed in a channel-die to form two sets of macro-SBs. The deformation-induced sub-structures and local changes in crystallographic orientations were characterized by scanning electron microscopy equipped with a high-resolution electron backscattered diffraction facility. It was found that the mechanism of micro-/macro-SBs formation is strictly crystallographic. In all the grains of the sheared zone a strong tendency to strain-induced re-orientation could be observed. Their crystal lattice rotated in such a way that one of the {111} slip planes became nearly parallel to the shear plane and the <011> (or <112>) direction became parallel to the direction of maximum shear. This crystal lattice rotation led to the formation of specific SBs components which facilitates slip propagation across grain boundaries without any visible variation in the slip direction.

ATEM investigation of experimentally annealed sillimanite: new constraints for the SiO2–Al2O3 join

2000 ◽  
Vol 64 (2) ◽  
pp. 247-254 ◽  
Author(s):  
P. Raterron ◽  
M. Carpenter ◽  
J.-C. Doukhan
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Phase Diagram ◽  
Triple Junctions ◽  
Defect Model ◽  
Point Defect Model ◽  
Partial Melt ◽  
Transmission Electron ◽  
Nucleation Sites ◽  
Preferential Nucleation

AbstractFour samples of Fe-bearing prismatic sillimanite, containing ∼1 wt.% Fe2O3, were annealed experimentally at temperatures of 1465 and 1675°C, and pressures between 1 atm and 30 kbar. Transmission electron microscopy (TEM) and analytical TEM (ATEM) investigation of the samples reveal that the starting material partly transformed into mullite during the annealing, and that this process was assisted by partial melting. The exsolved partial melt (now a glass), observed at triple junctions and in the form of small precipitates (∼10–1000 nm in size) within the sillimanite matrix, contains >80 wt.% SiO2. It also contains ∼11 wt.% Al2O3, some FeO and detectable amounts of K2O and CaO. Dissociated c dislocations in sillimanite are preferential nucleation sites for SiO2-rich precipitates. The equilibrium compositions of residual sillimanite-mullite were measured with a 2 nm wide probe at the interface with the SiO2-rich glass in each sample after heat treatment. We used these equilibrium compositions to constrain the parameters of a point defect model for sillimanite mullitization proposed by Raterron et al. (1999). With the revised parameterization, it is now possible to calculate the position of the boundary between fields of mullite + melt and mullite in the SiO2–Al2O3 phase diagram, and to predict the effect of pressure on this boundary. However, to be used as a standard, this model still needs to be calibrated in the pure SiO2–Al2O3 system (without impurities such as iron).

Texture Evolution during Recrystallisation of Cold Rolled TWIP Steel

2011 ◽  
Vol 702-703 ◽  
pp. 647-650
Author(s):  
Ahmed A. Saleh ◽  
Elena V. Pereloma ◽  
Azdiar A. Gazder
Keyword(s):  
Cold Rolling ◽  
Twip Steel ◽  
Texture Evolution ◽  
Rolling Texture ◽  
Austenitic Steels ◽  
X Ray Diffraction ◽  
Energy Materials ◽  
X Ray ◽  
Nucleation Sites ◽  
Cold Rolled

A TWinning Induced Plasticity (TWIP) steel was cold rolled to 42% thickness reduction followed by isochronal annealing for 300 s between 600-850 °C. Bulk texture evolution during recrystallisation was investigated by X-Ray Diffraction. While the development of the α-fibre after cold rolling is typical of low stacking fault energy materials, anomalously higher intensities were noted for the Goss ({110}) compared to Brass ({110}) orientations. Upon recrystallisation, the main rolling texture components were retained and ascribed to nucleation at orientations close to those of the deformed matrix followed by annealing twinning which leads to crystallographically identical variants. Unlike previous texture investigations on austenitic steels, the relatively homogeneous deformation microstructure and uniform distribution of subsequent nucleation sites led to the retention of the F ({111}) orientation. Moreover, the firsthand observation of the Rotated Copper ({112}) orientation in TWIP steel is attributed to the second order twinning of the A ({110}) orientation.

Microstructure and Texture Development in Ti-5Al-5Mo-5V-3Cr Alloy during Cold Rolling and Annealing

2013 ◽  
Vol 551 ◽  
pp. 210-216 ◽  
Author(s):  
Alireza Ghaderi ◽  
Peter D. Hodgson ◽  
Matthew R. Barnett
Keyword(s):  
Cold Rolling ◽  
Electron Backscatter Diffraction ◽  
Texture Evolution ◽  
Shear Bands ◽  
Annealing Treatment ◽  
Β Phase ◽  
Three Samples ◽  
Cold Rolling And Annealing ◽  
Cold Rolled ◽  
Phase Sample

This study focuses on the microstructure and texture evolution of a Ti-5Al-5Mo-5V-3Cr alloy during cold rolling and annealing treatments. Three samples with different initial microstructures were cold rolled to a 40% reduction in thickness. The starting microstructure of one sample was single β phase while two other specimens were α+β phases with different α particle sizes, distributed in β grains. For all three samples, the average size of primary β grains was 150 µm. The cold rolled specimens were then annealed at 860 °C (10 °C above the β transus temperature) for 5 minutes followed by water quenching. Microstructure development during cold rolling and recrystallization was studied by scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD) technique. Microstructure investigations showed that massive amount of shear bands occurred during the cold rolling of the single β phase sample while only a few shear bands were observed in the α+β cold rolled microstructures. The cold rolled texture of the sample comprised of a single β phase contains a gamma fibre (//ND) and a partial alpha fibre (//RD). Annealing treatment decreased the intensity of the cold rolled texture in the single β phase sample. Also, it was found that the presence of α precipitates changes the common annealing texture observed in the single β phase specimen.

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