Texture Gradient in a Single Pass ECAPed Pure Mg by Neutron Radiation

2008 ◽  
Vol 584-586 ◽  
pp. 513-517 ◽  
Author(s):  
Wei Min Gan ◽  
Heinz Günter Brokmeier ◽  
Hai Chang ◽  
Ming Yi Zheng ◽  
Kun Wu
Keyword(s):  
Texture Evolution ◽  
Neutron Radiation ◽  
Deformation Mode ◽  
Stress And Strain ◽  
Texture Gradient ◽  
Inhomogeneous Distribution ◽  
Single Pass ◽  
Deformation Textures ◽  
Outgoing Channel ◽  
Mode A

Single pass ECAP of pure Magnesium was performed and stopped after 50 % deformation; textures thereafter at the ingoing, the deformation and the outgoing channel were characterized by neutron radiation and related to the deformation mode. A gradient texture evolution was obtained, which was attributed to the inhomogeneous distribution of the effective stress and strain, and also the inevitable existence of friction.

scholarly journals Texture Evolution During the Drawing of Low Carbon Steel

1994 ◽  
Vol 22 (4) ◽  
pp. 261-278 ◽  
Author(s):  
C. Schuman ◽  
C. Esling ◽  
M. J. Philippe ◽  
M. Hergesheimer ◽  
M. Jallon ◽  
...  
Keyword(s):  
Deformation Rate ◽  
Early Stage ◽  
Texture Evolution ◽  
Reduction Rate ◽  
Carbon Steels ◽  
Texture Gradient ◽  
Interstitial Free ◽  
Low Carbon ◽  
Fibre Texture ◽  
Drawing Direction

This study deals with the texture evolution during drawing of interstitial-free low carbon steels under different conditions to study the possible influence of the drawing direction, deformation rate and metal/die friction coefficient. The drawing has been carried out without intermediary annealing, with constant die angle and deformation rate per pass. In all cases, a 〈110〉 fibre texture has been observed at the early stage of deformation (a few percents). The drawing direction, whether alternate or unidirectional, has little effect on texture. Slight differences only in the intensity of peaks on pole figures (PFs) are noted. Alternate drawing leads to higher drawing limits. The grain size affects both the texture and the mechanical properties, which are improved by fine grains. For industrial drawing, i.e. at a high deformation rate, no texture gradient has been clearly observed. Nevertheless, slight differences have been noted in the PF intensities, with generally a slightly sharper texture in the core, compared to the surface. The microhardness tests show no hardness gradient. In slow drawing (low deformation rate), there is a weak texture gradient which disappears at larger deformation. In order to visualize the influence of the metal/die friction, we used a material covered with copper. Results show that at a given reduction rate, the material covered with copper shows peak intensities on the (110) PF which are half these of a material drawn under conventional conditions. The drawing textures of BCC materials always present a 〈110〉 fibre texture. A modeling of the texture evolution during drawing has also been carried out using the Taylor model.

scholarly journals Study on Texture and Grain Orientation Evolution in Cold-Rolled BCC Steel by Reaction Stress Model

Crystals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 680
Author(s):  
Ning Zhang ◽  
Li Meng ◽  
Wenkang Zhang ◽  
Weimin Mao
Keyword(s):  
Elastic Anisotropy ◽  
Stress And Strain ◽  
Slip Systems ◽  
Grain Orientations ◽  
Bcc Structure ◽  
Deformation Textures ◽  
Cold Rolled ◽  
Rolling Deformation ◽  
Stress Accumulation ◽  
Accumulation Coefficients

The evolution of texture and grain orientations in a cold-rolled steel of BCC structure was simulated by a reaction stress (RS) model. The results show that cold-rolled texture could be assessed based on a RS model because the stress and strain are considered to remain consistent in the deformation process. The strain consistency is actualized by the cooperation of two plastic strains and an elastic strain. The accumulation range of each reaction stress and different activation abilities of {110}<111> and {112}<111> slip systems strongly affect the calculated deformation textures. The values of reaction stress are influenced by elastic anisotropy; however, the effects are greatly reduced because its corresponding reaction stress accumulation is limited. Typical α-fiber and γ-fiber textures are achieved when the reaction stress accumulation coefficients αijs are chosen suitably. Furthermore, the αij values that are selected based on statistically calculated textures can also be used to simulate the orientation change of multiple orientations. The existence of reaction stress is able to stabilize crystallographically symmetrical orientations under rolling deformation, in which the Schmid factors of several slip systems are identical.

Texture Formation in Flow Formed Ferritic Steel Tubes and the Influence of the Process Parameters

2014 ◽  
Vol 783-786 ◽  
pp. 2602-2607 ◽  
Author(s):  
Dimitrios Tsivoulas ◽  
Gabor Timar ◽  
Martin Tuffs ◽  
Joao Quinta da Fonseca ◽  
Michael Preuss
Keyword(s):  
Process Parameters ◽  
Principal Direction ◽  
Deformation Mode ◽  
Element Model ◽  
Ferritic Steels ◽  
Texture Gradient ◽  
Steel Tubes ◽  
Complex Deformation ◽  
Crystal Plasticity Finite Element ◽  
Strain Components

The crystallographic textures of flow formed parts are of great scientific interest as they result from a complex deformation mode that comprises strain components in the axial and hoop directions. In general they resemble those of the rolling type but with slight differences. The present paper analyses the effects of certain process parameters, such as roller contact angle, feed rate, and preform hardness, since these are crucial in defining the forces acting in each principal direction of the component. Additionally, the development of a texture gradient through the wall thickness is also discussed. Texture predictions from a crystal plasticity finite-element model were also employed to support the experimental data and interpret the deformation mechanisms. Finally, the diverse nature of the flow formed textures is verified by annealing treatments at 700°C, which yields the typical gamma-fibre encountered in rolled ferritic steels upon recrystallisation in conjunction with the strengthening of the (113)[1-10] component.

scholarly journals Analysis of Reversed Torsion of FCC Metals Using Polycrystal Plasticity Models

2015 ◽  
Vol 07 (03) ◽  
pp. 1550033 ◽  
Author(s):  
X. Q. Guo ◽  
H. Wang ◽  
P. D. Wu ◽  
X. B. Mao
Keyword(s):  
Large Strain ◽  
Texture Evolution ◽  
Constitutive Models ◽  
Stress And Strain ◽  
Fcc Metals ◽  
Strain Behavior ◽  
Polycrystal Plasticity ◽  
Self Consistent ◽  
Overall Performance ◽  
Fixed End

Large strain behavior of FCC polycrystals during reversed torsion are investigated through the special purpose finite element based on the classical Taylor model and the elastic-viscoplastic self-consistent (EVPSC) model with various Self-Consistent Schemes (SCSs). It is found that the response of both the fixed-end and free-end torsion is very sensitive to the constitutive models. The models are assessed through comparing their predictions to the corresponding experiments in terms of the stress and strain curves, the Swift effect and texture evolution. It is demonstrated that none of the models examined can precisely predict all the experimental results. However, more careful observation reveals that, among the models considered, the tangent model gives the worst overall performance. It is also demonstrated that the intensity of residual texture during reverse twisting is dependent on the amounts of pre-shear strain during forward twisting and the model used.

scholarly journals Textures in Multi-Directional Forged Mg by Neutron Diffraction

2010 ◽  
Vol 146-147 ◽  
pp. 879-882 ◽  
Author(s):  
Wei Min Gan ◽  
Heinz Guenter Brokmeier ◽  
Ming Yi Zheng ◽  
Kun Wu
Keyword(s):  
Neutron Diffraction ◽  
Texture Analysis ◽  
Deformation Mechanism ◽  
Texture Evolution ◽  
Inhomogeneous Distribution

Texture evolution in the MDF processed ZK60 along forging axis was investigated by advanced neutron diffraction. Texture analysis was related to the deformation mechanism. Results showed that basal planes deformation was dominated and accommodated by non-basal and twinning. Gradient texture indicated an inhomogeneous distribution of imposed strains along forging direction. This could be related to the non-precise MDF processing.

Texture Evolution of Rolled AA3003 Alloy Sheets after Annealing

2007 ◽  
Vol 353-358 ◽  
pp. 579-582
Author(s):  
Kee Joo Kim ◽  
Joo Sung Kim ◽  
Cheol Woong Kim ◽  
Il Seon Sohn ◽  
Jin Yi Lee ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Recrystallization Texture ◽  
Texture Evolution ◽  
Reduction Ratio ◽  
Subsequent Annealing ◽  
Treatment Conditions ◽  
Deformation Textures ◽  
High Reduction ◽  
Cold Rolled ◽  
Ratio Reduction

To fabricate the aluminum alloys with good drawability, the textures evolution of the 3003 aluminum alloy sheets after rolling and subsequent annealing was studied. The measurement of the deformation textures was carried out for the sheets in which were cold rolled with high reduction ratio by using the symmetric roll. In addition, the change of the recrystallization texture was investigated after heat-treatments of the rolled sheets with various heat treatment conditions. Rolling without lubrication and subsequent annealing led to the formation of favorable rot-CND {001}<110> and γ-fiber ND//<111> textures in 3003 aluminum alloy sheets. From the results, the γ-fiber ND//<111> component well evolved during rolling at high reduction ratio (reduction over 90%, l/d parameter over 6.0). Among shear deformation textures, the γ-fiber ND//<111> was not rotated during recrystallization (350°C) in special condition.

Study of Microstructure and Texture Evolution Using In-Situ EBSD Investigations and SE Imaging in SEM

2006 ◽  
Vol 519-521 ◽  
pp. 809-814 ◽  
Author(s):  
Hans Bjerkaas ◽  
Snorre Kjørstad Fjeldbo ◽  
Hans Jørgen Roven ◽  
Jarle Hjelen ◽  
Rémi Chiron ◽  
...  
Keyword(s):  
Texture Evolution ◽  
Initial Orientation ◽  
Lattice Rotation ◽  
Complex Nature ◽  
Texture Gradient ◽  
Slip Activity ◽  
Crystallographic Slip ◽  
Simple Tension ◽  
Grain Orientations

The crystallographic slip activity in several grains deformed by simple tension is determined by use of in-situ deformation in combination with Electron Back Scattering Diffraction (EBSD)-investigations and Secondary Electron (SE) imaging. This technique is also used to determine grain lattice rotation paths of grains with different initial orientation, providing information on basic deformation mechanisms of grains present in texture gradients. Both slip activity and grain lattice rotation paths depend on the initial orientation and are influenced by the neighbouring grain orientations. This indicates that predictions of the forming behaviour of extruded profiles with a strong through thickness texture gradient relate to a very complex nature.

The Application of Multiscale Modelling for the Prediction of Plastic Anisotropy and Deformation Textures

2007 ◽  
Vol 550 ◽  
pp. 13-22 ◽  
Author(s):  
Paul van Houtte ◽  
Albert Van Bael ◽  
Marc Seefeldt
Keyword(s):  
Constitutive Model ◽  
Multilevel Models ◽  
Plastic Anisotropy ◽  
Forming Limit ◽  
Stress And Strain ◽  
Finite Element Models ◽  
Identification Procedure ◽  
Macro Scale ◽  
Deformation Textures ◽  
Level Model

Finite element models for metal forming and models for the prediction of forming limit strains should be as accurate as possible, and hence should take effects due to texture, microstructure and substructure (dislocation patterns) into account. To achieve this, a hierarchical type of modelling is proposed in order to maintain the balance between calculation speed (required for engineering applications) and accuracy. This means that the FE models work with an analytical constitutive model, the parameters of which are identified using results of multilevel models. The analytical constitutive model will be discussed, as well as the identification procedure. The multilevel models usually connect the macro-scale with a meso-scale (grain level) via a homogenisation procedure. They can also be used to make predictions of deformation textures. These will be quantitatively compared with experimentally obtained rolling textures of steel and aluminium alloys. It was found that only models which to some extent take both stress and strain interactions between adjacent grains into account perform well. Finally an example of a three level model, also including the micro-scale (i.e. the dislocation substructure), will be given.

Analysis of Deformation Textures and Microstructure in ECAE Processed Copper Single Crystals via Route C

2007 ◽  
Vol 561-565 ◽  
pp. 929-932
Author(s):  
Gang Wang ◽  
Shi Ding Wu ◽  
Yan Dong Wang ◽  
Ya Ping Zong ◽  
Claude Esling ◽  
...  
Keyword(s):  
Single Crystals ◽  
Equal Channel Angular Extrusion ◽  
Texture Evolution ◽  
Effective Means ◽  
Pure Copper ◽  
Ultrafine Grained ◽  
Deformation Textures ◽  
Ultrafine Grained Materials ◽  
Copper Single Crystals ◽  
Mechanisms Of Plastic Deformation

Equal channel angular extrusion (ECAE) is an effective means of producing ultrafine-grained materials with extraordinary mechanical properties. Texture evolution and microstructure in pure copper single crystals processed by ECAE for up to five passes via route C are investigated to understand mechanisms of plastic deformation and grain refinement during ECAE. The experimental textures after the third pass ECAE process recovers that after one pass ECAE process. The main textures approaches a stable one after four passes of ECAE process via Route C while the intensity of main texture components decreases gradually. Local TEM-OIM measurements shows that grain subdivision in ECAE-processed samples occurs with the formation of many low angle grain boundaries.

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