The Experts below are selected from a list of 21180 Experts worldwide ranked by ideXlab platform
Said Ahzi - One of the best experts on this subject based on the ideXlab platform.
-
coupled effects of the lattice rotation definition twinning and interaction strength on the fcc rolling Texture Evolution using the viscoplastic ϕ model
International Journal of Plasticity, 2013Co-Authors: Wei Wen, Said Ahzi, S Mguil, J GracioAbstract:Abstract Prediction of the rolling Texture Evolution in FCC metals is controlled by interaction laws, deformation mechanisms and definition of the lattice spin. The coupled effect of these three factors on the FCC rolling Texture Evolution is hereby analyzed using the viscoplastic ϕ -model. Without the Eshelby theory, this model yields an interaction law spanning predicted results from the upper to lower bound ones by varying a scalar weight parameter ϕ ( 0 ϕ 1 ). In this work, two definitions of the lattice spin, the mathematical analysis (MA) and the plane–strain analysis (PSA), are considered in the ϕ -model. The influence of the MA and PSA definitions on the FCC rolling Texture Evolution is deeply analyzed in conjunction with twinning and grain interaction strength, from a stiff to a more compliant interaction.
-
Analysis of Texture Evolution in hcp polycrystals using a viscoplastic intermediate approach
International Journal of Material Forming, 2009Co-Authors: S. M’guil, Said Ahzi, J. J. GracioAbstract:In this work, we propose the used of the new viscoplastic ϕ-model to predict Texture Evolution in hcp metals. We will compare our results to those predicted by the viscoplastic self-consistent (VPSC) model. In both approaches, elasticity is neglected and crystallographic shearing is the only mechanism assumed to cause plastic deformation. Axisymmetric compression test is performed for different values of the parameters controlling the grain interaction strength for both approaches. Predicted stress-strain curves, Texture Evolution and slip activity are compared and conclusions are drawn. We show that the ϕ-model allows for correct prediction while it is much easier to formulate and to numerically implement.
-
Modelling of deformation plasticity and Texture Evolution in NiAl polycrystals
Modelling and Simulation in Materials Science and Engineering, 1999Co-Authors: Said AhziAbstract:We present experimental results for Texture Evolution in NiAl polycrystals under compression at elevated temperatures of initially extruded samples. Based on these experimental observations and on existing experimental results, we discuss the operating slip systems in NiAl and address the lack of five independent slip systems in this ordered intermetallic material. We also propose the use of crystal plasticity modelling to simulate Texture Evolution in NiAl. We use the projection model of Parks and Ahzi which accounts explicitly for the missing degrees of kinematic freedom due to the activation of only three independent slip systems in NiAl crystals. Different sets of slip systems were used in this model and in the Taylor model to simulate Texture Evolution under uniaxial tension of initially isotropic NiAl polycrystals, and uniaxial compression of initially Textured polycrystals. The contribution of each set of slip systems to texturing is discussed. Predicted results are compared with experimental observations. We conclude that the use of the projection model with the three independent slip systems, experimentally observed to operate at elevated temperatures, leads to Texture predictions in good agreement with experiments.
-
Modeling Dynamic Behavior and Texture Evolution in Pure Tantalum (Ta)
1997Co-Authors: Scott E. Schoenfeld, Said Ahzi, Kenneth S VecchioAbstract:Abstract : In order to model high strain rate deformation and Texture Evolution in commercially pure tantalum (Ta), description for the thermal elastic viscoplastic behavior of Ta single crystals is considered along with an associated polycrystal averaging scheme. The description incorporates a temperature dependent model for pencil glide on the planes of maximum resolved shear stress. Calculated stress strain data and Texture Evolution for this model are compared to those of a restricted glide model and to experimental data.
-
Micromechanical Modeling of Plasticity and Texture Evolution in Semi-Crystalline Polymers
Inelastic Deformation of Composite Materials, 1991Co-Authors: David M. Parks, Said AhziAbstract:The microstructure of many semi-crystalline polymers consists of rather broad, thin composite inclusions of crystalline and amorphous domains. A micromechanically based composite model is proposed to study plasticity and Texture Evolution in these composite materials. Special consideration is given to molecular chain inextensibily within the crystalline phase. Molecular alignment within the amorphous phase is accounted for by introducing a back stress tensor in the corresponding flow rule. Interface compatibility and traction equilibrium are considered within each composite inclusion. A modified Taylor-like localization law is proposed to deal with the singularity problems related to kinematic deficiency in some inclusions. Applications of this model are made to predict the behavior and deformation Texture Evolution in initially isotropic High Density Polyethylene. Comparisons of our predictions to experimental data are given.
Frédéric Barlat - One of the best experts on this subject based on the ideXlab platform.
-
Hardening behavior and Texture Evolution of TWIP steel during strain path change
IOP Conference Series: Materials Science and Engineering, 2015Co-Authors: Wei Wen, Frédéric Barlat, M. Borodachenkova, António Pereira, J. J. GracioAbstract:Polycrystal materials exhibit large changes in the flow stress and hardening behavior during the strain path change. Such changes are related with the crystallographic Texture anisotropy and the rearrangement of dislocation structure during the pre-loading. These effects have been captured by a dislocation hardening model embedded in the visco-plastic selfconsistent (VPSC) model. In this work, the Texture Evolution and mechanical behavior of TWIP steel during the strain path change are investigated. The experimental studies are carried out on rolled TWIP steel sheet. The mechanical responses are obtained under tensile tests along rolling direction, followed by tension along the directions with 0° and 90° from the pre-loading direction. The simulated results of strain-stress curves and the Texture Evolution are in good agreement with the experimental data.
-
Texture Evolution of FCC sheet metals during deep drawing process
International Journal of Mechanical Sciences, 2000Co-Authors: Shi Hoon Choi, Jae-hyung Cho, Kwansoo Chung, Frédéric BarlatAbstract:Abstract The stability of ideal orientations and Texture Evolution was investigated for FCC sheet metals during deep drawing. Lattice rotation fields around ideal orientations were numerically predicted using a rate-sensitive polycrystal model with full constraint boundary conditions. In order to evaluate the strain path during deep drawing of an AA1050, simulations using a finite element analysis were carried out. The stability of orientations and Texture formation was examined at sequential paths such as flange deformation, transition and wall deformation. Depending on the initial location in the blank, the deviation from the plane strain state in the flange deformation path decreased the orientation density around P {0 1 1}〈8 11 11 〉 and shifted the final stable end orientation from P to Yf near {1 1 1}〈 1 1 2〉 . The Texture Evolution in AA1050 sheet metals during deep drawing was experimentally investigated. The change of orientation density around ideal orientations in the RD and TD samples was in good agreement with the rate-sensitive polycrystal model.
Wei Wen - One of the best experts on this subject based on the ideXlab platform.
-
Hardening behavior and Texture Evolution of TWIP steel during strain path change
IOP Conference Series: Materials Science and Engineering, 2015Co-Authors: Wei Wen, Frédéric Barlat, M. Borodachenkova, António Pereira, J. J. GracioAbstract:Polycrystal materials exhibit large changes in the flow stress and hardening behavior during the strain path change. Such changes are related with the crystallographic Texture anisotropy and the rearrangement of dislocation structure during the pre-loading. These effects have been captured by a dislocation hardening model embedded in the visco-plastic selfconsistent (VPSC) model. In this work, the Texture Evolution and mechanical behavior of TWIP steel during the strain path change are investigated. The experimental studies are carried out on rolled TWIP steel sheet. The mechanical responses are obtained under tensile tests along rolling direction, followed by tension along the directions with 0° and 90° from the pre-loading direction. The simulated results of strain-stress curves and the Texture Evolution are in good agreement with the experimental data.
-
coupled effects of the lattice rotation definition twinning and interaction strength on the fcc rolling Texture Evolution using the viscoplastic ϕ model
International Journal of Plasticity, 2013Co-Authors: Wei Wen, Said Ahzi, S Mguil, J GracioAbstract:Abstract Prediction of the rolling Texture Evolution in FCC metals is controlled by interaction laws, deformation mechanisms and definition of the lattice spin. The coupled effect of these three factors on the FCC rolling Texture Evolution is hereby analyzed using the viscoplastic ϕ -model. Without the Eshelby theory, this model yields an interaction law spanning predicted results from the upper to lower bound ones by varying a scalar weight parameter ϕ ( 0 ϕ 1 ). In this work, two definitions of the lattice spin, the mathematical analysis (MA) and the plane–strain analysis (PSA), are considered in the ϕ -model. The influence of the MA and PSA definitions on the FCC rolling Texture Evolution is deeply analyzed in conjunction with twinning and grain interaction strength, from a stiff to a more compliant interaction.
Guodong Wang - One of the best experts on this subject based on the ideXlab platform.
-
microstructure and Texture Evolution of strip casting 3 wt si non oriented silicon steel with columnar structure
Journal of Magnetism and Magnetic Materials, 2011Co-Authors: Hai-tao Liu, Zhenyu Liu, Guangming Cao, Guodong WangAbstract:Abstract An Fe-3 wt%Si strip with columnar structure and pronounced {0 0 1}〈0 v w〉 Texture was produced using a twin-roll strip caster. Then the as-cast strip was cold-rolled and annealed. The microstructure and Texture Evolution along the processing steps was investigated. It is found that inhomogeneous microstructure is produced in both cold-rolled and final annealed samples due to the large initial grains. The cold rolling Texture is dominated by pronounced a-fiber Texture and relatively strong γ-fiber Texture. The final recrystallization Texture is characterized by {0 0 1}〈0 1 0〉, {0 0 1}〈2 1 0〉, {1 1 0}〈0 0 1〉 Texture and a slightly shifted {1 1 1}〈1 1 2〉 component. The microstructural inhomogeneity plays an important role in the Texture Evolution.
-
Microstructure and Texture Evolution of Strip Casting Fe-6.2wt%Si Steel
Advanced Materials Research, 2011Co-Authors: Hai-tao Liu, Z.y. Liu, Yu Sun, Yi Qing Qiu, Guodong WangAbstract:An Fe-6.2wt%Si as-cast strip with equiaxed grains and obvious {001} fiber Texture was produced by twin-roll strip casting process. The as-cast strip was successively performed by hot rolling, warm rolling and annealing. The microstructure and Texture Evolution at each process stage were investigated by using electron backscatter diffraction and x-ray diffraction. It was found that the finally annealed sheet was characterized by large grain size, mild γ-fiber Texture and obvious {001} fiber Texture. Therefore, a high magnetic induction and a low core loss were obtained in the sheet.
W.c. Liu - One of the best experts on this subject based on the ideXlab platform.
-
Effect of Preheat Treatment on the Texture Evolution During Cold Rolling of AA 3003 Aluminum Alloy
Journal of Materials Engineering and Performance, 2015Co-Authors: Wen-kui Wang, J.x. Zhang, W.c. LiuAbstract:The effect of preheat treatment on the Texture Evolution during rolling of AA 3003 aluminum alloy was investigated by x-ray diffraction. The Texture Evolution during rolling was quantified in terms of a simple relation between the Texture volume fractions and true rolling strain. It was found that the alloy annealed at 538 °C had a higher value of k i and a lower value of n i than the alloy annealed at 593 °C for all the Texture components. The difference in Texture Evolution between the two preheat treatments was mainly attributed to the initial Texture. The alloy annealed at 538 °C had a higher formation rate of β fiber component than the alloy annealed at 593 °C because of the relatively weak cube Texture and the presence of the P Texture.
-
Comparison of Texture Evolution between different thickness layers in cold rolled Al–Mg alloy
Materials Characterization, 2011Co-Authors: Ming-biao Chen, Y.m. Zhao, H. Yuan, W.c. LiuAbstract:Abstract The Texture Evolution at different thickness layers in cold rolled AA 5052 aluminum alloy was analyzed quantitatively in terms of a simple relation between the Texture volume fractions and true rolling strain. The effect of roll-gap geometry, friction between the roll and sheet and initial through-thickness Texture gradient on the Texture Evolution during rolling was determined. The results show that the roll-gap geometry decreases the rate of Texture Evolution at the quarter layer in the early stage of deformation. In the case of oil as a lubricant, the very small friction between the roll and sheet slightly decreases the rate of Texture Evolution at the surface layer. At large strains the low rate of Texture Evolution at the center layer can be attributed to its strong initial cube Texture.
-
Effect of precipitation on rolling Texture Evolution in continuous cast AA 3105 aluminum alloy
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2006Co-Authors: W.c. Liu, Chi-sing Man, Dierk Raabe, James G. MorrisAbstract:The Texture Evolution of continuous cast (CC) AA 3105 aluminum alloy during cold rolling was investigated by X-ray Bragg diffraction. The influence of the precipitation state on the Texture Evolution during rolling was determined. The results show that the precipitates in a CC AA 3105 aluminum alloy affect the Texture Evolution during rolling. As the amount of precipitates increases and the size of precipitates decreases, the rate of disappearance of the cube, r-cube, and remainder components and the rate of formation of the β fiber decrease. The presence of large precipitates in a CC AA 3105 aluminum alloy hardly affects the Texture Evolution.
-
Texture Evolution of continuous cast and direct chill cast AA 3003 aluminum alloys during cold rolling
Scripta Materialia, 2004Co-Authors: W.c. Liu, Tongguang Zhai, James G. MorrisAbstract:Abstract The Texture Evolution of continuous cast (CC) and direct chill cast (DC) AA 3003 aluminum alloys during cold rolling was investigated by X-ray diffraction. The relationship between Texture volume fractions and rolling true strain was described quantitatively by mathematical formulae. The effect of processing method (CC vs. DC) on Texture Evolution was determined.
-
Comparison of Texture Evolution during cold rolling between direct chill and continuous cast aluminium alloy 5052
Materials Science and Technology, 2003Co-Authors: Y.m. Zhao, W.c. Liu, James G. MorrisAbstract:AbstractHot bands of direct chill cast (DC) and continuous cast (CC) aluminium alloy 5052 were cold rolled to different reductions after being annealed at 454 ° C for 4 h. The Texture Evolution during cold rolling was investigated for both DC and CC AA 5052 by determining the orientation distribution functions of the cold rolled specimens via X-ray diffraction. Texture Evolution during cold rolling was predicted by empirical formulas of the variation of the Texture components with true strain. The results show that the processing method (DC versus CC) has an effect on the Texture of annealed hot bands and the Texture Evolution during subsequent cold rolling.
