Effects of Driving Force and Boundary Migration Velocity on Formation of Recrystallization Texture in Cold Rolled Pure Aluminum Sheets

2013 ◽  
Vol 753 ◽  
pp. 257-262 ◽  
Author(s):  
Wei Min Mao ◽  
Ping Yang
Keyword(s):  
Grain Growth ◽  
Driving Force ◽  
Recrystallization Texture ◽  
Pure Aluminum ◽  
Solute Drag ◽  
Texture Formation ◽  
Oriented Growth ◽  
Aluminum Sheets ◽  
Zener Drag ◽  
Cold Rolled

The effects of net driving force for migration of high angle grain boundaries were emphasized beside many other factors which could influence the process of texture formation during recrystallization annealing of 95% cold rolled pure aluminum sheets. The net driving force consists basically of stored energy. However, it could be reduced by recovery, boundary drag, solute drag and Zener drag in different extents, in which only boundary drag is mis-orientation dependent. It was indicated that both oriented nucleation and oriented growth have obvious influence on recrystallization texture, and how far they influence the texture depends also on the level of net driving force when the grain growth starts during annealing. Oriented growth, which is induced by the differences in boundary drag of differently oriented grains, and the corresponding texture formation, could be observed easily when the recrystallization proceeds under relative higher solute drag and Zener drag in commercial purity aluminum. The oriented nucleation process prevails during recrystallization of sufficiently recovered high purity aluminum with very low solute drag and Zener drag, after which strong cube texture forms. In this case the oriented growth indicates limited effect. Both the oriented growth and oriented nucleation will fail if high purity deformation matrix without clear solute drag and Zener drag has not experienced an obvious recovery before recrystallization grain growth, since extremely high net driving force leads to very small critical nucleus size and multiplicity of growing grains, which results in randomization of recrystallization texture.

Magnetically Controlled Recrystallization Texture in Titanium

2004 ◽  
Vol 467-470 ◽  
pp. 483-488 ◽  
Author(s):  
Dmitri A. Molodov ◽  
A.D. Sheikh-Ali
Keyword(s):  
Magnetic Field ◽  
Magnetic Susceptibility ◽  
Grain Growth ◽  
Texture Component ◽  
Driving Force ◽  
Recrystallization Texture ◽  
Rolling Direction ◽  
Field Direction ◽  
Titanium Sheet ◽  
Cold Rolled

The annealing of cold rolled (82%) titanium sheet at 750°C in a magnetic field of 19.4 Tesla results in a distinct difference between texture peaks when the sample is tilted by +30° or -30° to the field direction around the rolling direction, i.e. c (<0001>)-axis of grains corresponding to one texture component is aligned normal to the field direction. This result is attributed to grain growth affected by an additional driving force arising in a magnetic field by the anisotropy of the magnetic susceptibility of titanium.

scholarly journals Texture Selection Mechanisms during Recrystallization and Grain Growth of a Magnesium-Erbium-Zinc Alloy

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 171
Author(s):  
Fatim-Zahra Mouhib ◽  
Fengyang Sheng ◽  
Ramandeep Mandia ◽  
Risheng Pei ◽  
Sandra Korte-Kerzel ◽  
...  
Keyword(s):  
Grain Growth ◽  
Ternary Alloy ◽  
Solute Drag ◽  
Tensile Tests ◽  
Electron Back Scatter Diffraction ◽  
Zinc Alloy ◽  
Uniaxial Tensile ◽  
Microstructural Stability ◽  
Solid Solution Strengthening ◽  
Zener Drag

Binary and ternary Mg-1%Er/Mg-1%Er-1%Zn alloys were rolled and subsequently subjected to various heat treatments to study texture selection during recrystallization and following grain growth. The results revealed favorable texture alterations in both alloys and the formation of a unique ±40° transvers direction (TD) recrystallization texture in the ternary alloy. While the binary alloy underwent a continuous alteration of its texture and grain size throughout recrystallization and grain growth, the ternary alloy showed a rapid rolling (RD) to transvers direction (TD) texture transition occurring during early stages of recrystallization. Targeted electron back scatter diffraction (EBSD) analysis of the recrystallized fraction unraveled a selective growth behavior of recrystallization nuclei with TD tilted orientations that is likely attributed to solute drag effect on the mobility of specific grain boundaries. Mg-1%Er-1%Zn additionally exhibited a stunning microstructural stability during grain growth annealing. This was attributed to a fine dispersion of dense nanosized particles in the matrix that impeded grain growth by Zener drag. The mechanical properties of both alloys were determined by uniaxial tensile tests combined with EBSD assisted slip trace analysis at 5% tensile strain to investigate non-basal slip behavior. Owing to synergic alloying effects on solid solution strengthening and slip activation, as well as precipitation hardening, the ternary Mg-1%Er-1%Zn alloy demonstrated a remarkable enhancement in the yield strength, strain hardening capability, and failure ductility, compared with the Mg-1%Er alloy.

scholarly journals Model Calculations of the Recrystallization Texture Formatio in α-Iron

1995 ◽  
Vol 23 (2) ◽  
pp. 87-114 ◽  
Author(s):  
U. Köhler ◽  
H. J. Bunge
Keyword(s):  
Recrystallization Texture ◽  
Selection Process ◽  
Deformation Texture ◽  
Primary Recrystallization ◽  
Texture Formation ◽  
Oriented Growth ◽  
Model Calculations ◽  
Bcc Metals ◽  
Growth Selection ◽  
Essential Assumption

Model calculations of primary recrystallization textures in bcc metals were carried out on the basis of a model which considers oriented nucleation as well as oriented growth. The influence of the input parameters, as deformation texture, nucleation distribution and growth law were investigated systematically. It is shown that the inhomogeneity of the deformed microstructure has to be taken into account. With this essential assumption the main features of the recrystallization texture formation can be explained by a growth selection process according to a 27∘ <110> and 84∘ <110> orientation relationship.

The Softening of a Dispersoid-Rich Commercial Al-Mn Alloy

2007 ◽  
Vol 550 ◽  
pp. 351-356 ◽  
Author(s):  
Hans Erik Ekström ◽  
Stian Tangen ◽  
O.V. Mishin ◽  
Lars Östensson
Keyword(s):  
Tensile Properties ◽  
Microstructural Evolution ◽  
Driving Force ◽  
High Strain ◽  
Subgrain Size ◽  
Zener Drag ◽  
Cold Rolled

The microstructural evolution during annealing of a commercial Al-Mn alloy cold rolled to a high strain was investigated using EBSD and Gallium Enhanced Microscopy. The precipitation of manganese, coarsening of precipitates and tensile properties were monitored at different stages. It was found that during recovery the subgrains grow until they reach the limiting subgrain size when the driving force has been reduced to the same level as the Zener drag from the dispersoids. New grains are nucleated at constituent particles and a few are able to grow. The softening during recovery and the onset of discontinuous recrystallisation are analyzed and discussed in terms of recent theories of recovery and recrystallisation.

scholarly journals Computer simulation of grain growth kinetics with solute drag

1999 ◽  
Vol 14 (3) ◽  
pp. 1113-1123 ◽  
Author(s):  
D. Fan ◽  
S. P. Chen ◽  
Long-Qing Chen
Keyword(s):  
Grain Boundary ◽  
Grain Growth ◽  
Growth Kinetics ◽  
Driving Force ◽  
Boundary Energy ◽  
Solute Drag ◽  
Lattice Diffusion ◽  
Diffuse Interface ◽  
Growth Exponent ◽  
Grain Growth Kinetics

The effects of solute drag on grain growth kinetics were studied in two-dimensional (2D) computer simulations by using a diffuse-interface field model. It is shown that, in the low velocity/low driving force regime, the velocity of a grain boundary motion departs from a linear relation with driving force (curvature) with solute drag. The nonlinear relation of migration velocity and driving force comes from the dependence of grain boundary energy and width on the curvature. The growth exponent m of power growth law for a polycrystalline system is affected by the segregation of solutes to grain boundaries. With the solute drag, the growth exponent m can take any value between 2 and 3, depending on the ratio of lattice diffusion to grain boundary mobility. The grain size and topological distributions are unaffected by solute drag, which are the same as those in a pure system.

Microstructure Instability during Particle and Solute Inhibited Grain Growth

2012 ◽  
Vol 715-716 ◽  
pp. 528-528
Author(s):  
Massimiliano Buccioni ◽  
Giuseppe Carlo Abbruzzese
Keyword(s):  
Grain Size ◽  
Size Distribution ◽  
Grain Growth ◽  
Grain Size Distribution ◽  
Ostwald Ripening ◽  
Secondary Recrystallization ◽  
Solute Drag ◽  
Abnormal Grain Growth ◽  
Second Phase ◽  
Zener Drag

Grain growth processes in real polycrystalline materials are mostly characterized by the presence of restraining forces, originating, among others, from second phase particles dispersion (Zener drag) or solute atoms segregating at the grain boundaries (solute drag). Both the restraining mechanisms were introduced in the framework of the statistical theory of grain growth, showing their peculiar effects on kinetics and on grain size distribution evolution [1,2,. The present work moves from the previous results and gives a further clarification of pseudo-steady state kinetics occurring under particular solute drag inhibition intensity and will discuss it in comparison with grain growth stagnation conditions produced by Zener drag. In case of second phase particle inhibiting grain growth, the normal case in real systems is the time and temperature dependence of the inhibition intensity due to the evolution of precipitates (e.g. Ostwald ripening. Such evolutions of inhibition, which typically drops with increasing temperature, can cause microstructure instabilities like abnormal grain growth or secondary recrystallization. It is thus introduced in the model a time-temperature depending inhibition drop, which influences both kinetics and grain size distribution evolution. Conditions for the onset of particular effects like abnormal grain growth are assessed and discussed.

Magnetically Controlled Grain Boundary Motion and Grain Growth in Zinc

2013 ◽  
Vol 753 ◽  
pp. 107-112 ◽  
Author(s):  
Christoph Günster ◽  
Dmitri A. Molodov ◽  
Günter Gottstein
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Grain Growth ◽  
Driving Force ◽  
Boundary Migration ◽  
Boundary Mobility ◽  
Grain Boundary Mobility ◽  
Cold Rolled ◽  
Grain Growth Kinetics ◽  
Grain Boundary Motion

The motion of grain boundaries in zinc bicrystals (99.995%) driven by the “magnetic” driving force was investigated. Planar symmetrical and asymmetrical tilt grain boundaries with rotation angles in the range between 60° and 90° were examined. At a given temperature the boundary migration rate was found to increase linearly with an applied driving force. The absolute grain boundary mobility was determined. The boundary mobility and its temperature dependence were found to depend on the misorientation angle and the inclination of the boundary plane. An application of a magnetic field during the annealing of cold rolled (90%) Zn-1.1%Al sheet specimens resulted in an asymmetry of the two major texture components. This is interpreted in terms of magnetically affected grain growth kinetics.

Sharpening of Cube Texture during Grain Growth in High Purity Aluminum

2004 ◽  
Vol 467-470 ◽  
pp. 899-904
Author(s):  
Takeshi Murakami ◽  
Shouichi Ochiai
Keyword(s):  
Heating Rate ◽  
Grain Growth ◽  
High Purity ◽  
Cube Texture ◽  
Electrolytic Capacitor ◽  
Lattice Rotation ◽  
Texture Formation ◽  
High Purity Aluminum ◽  
Cold Rolled ◽  
Sharp Cube Texture

Grain growth in cube-textured aluminum was investigated by transmission Laue photographs obtained at the same point in specimens with progressing annealing at the heating rate of 20 deg/h. High purity aluminum for electrolytic capacitor was cold rolled to 98 % reduction, and subsequently partially annealed at 230 °C for 6 h and rolled 22 % reduction. On the light rolling, asterisms toward RD were observed near by direct beam, suggesting that lattice rotation around TD was caused in cube grains by light rolling. After annealing to 300 deg, fine Laue spots were detected in the asterisms. Those fine spots were indexed as 100 spots due to diffraction in {100} nearly parallel to the ND-TD plane. After disappearance of Debye arcs due to diffraction in untransformed matrix, cube texture was observed with orientational spread around TD. With continuing annealing to 540 °C , grain growth occurred at the expense of cube grains whose orientations deviated from the exact cube orientation around TD , resulting in sharp cube texture formation.

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