Abstract: The effect of crystal orientation on the recovery and recrystallization of cold-rolled Ni
(99.96% purity) has been investigated. Particular attention was paid to the annealing response of
regions with either the Copper (C), Brass (B) or S rolling texture orientations. Samples with an
initial average grain size of approx. 500μm were deformed to strains of up to εvM = 4.5. As a result
of the large initial grain size, even after high rolling reductions it is possible to find sufficiently large
regions of material with similar crystal orientation to analyze the recovery and recrystallization
behaviour as a function of crystal orientation. Microstructural investigations were carried out in the
scanning electron microscope using both electron channeling contrast and electron backscatter
diffraction orientation mapping. Both the S and C orientation regions exhibit a heterogeneous
microstructure containing bands of localized deformation. The presence of volumes surrounded by
high angle boundaries in these regions strongly influences both the recovery and recrystallization
behaviour of the material. Twinning was observed also to play an important role in the generation of
recrystallized grains, with twin chains of up to 3 generations being observed.
Abstract: The softening process consists of recovery and recrystallization. Despite the significant effect
of recovery on the softening, recovery has not enjoyed the attention as much as recrystallizaion has
mostly due to difficulties in the microstructural characterization of recovery. The present study
introduced GOS qualitatively and quantitatively to gauge the microstructural evolution occurring
during annealing. Then the GOS analysis was applied to discern alloying effects on recrystallization
in hot deformed Al-Cu-Mg alloys. Recovery seems accountable for the retardation of recrystallization
in the Mn containing alloys. By adding Zr to Al-Cu-Mg-Mn, recrystallization could be further
Abstract: Variations in microstructure and mechanical properties of ZK60 alloy sheets were
investigated with aging time. ZK60 alloy sheets with a thickness of 1mm were prepared from a
casting ingot followed by homogenization and warm-rolling. Artificial aging process after solution
heat treatment (T6) affected both hardness variations and precipitates distributions with aging time.
Hardness variations were related to precipitates, i.e. rod-shaped ( 1 β ′ ) or disc shaped ( 2 β ′ ) particles.
Rod-shaped ( 1 β ′ ) precipitates mainly consist of Mg and Zn without Zr.
Abstract: Texture and microstructure of gold sheet were investigated during deformation and
subsequent annealing. The Brass, S and Copper (β-fiber) orientations are closely connected together
in the deformed microstructure. Recrystallization texture also was examined during isothermal
annealing at 500°C with reduction in area. Initial rolling textures with rotated cube and β-fiber
resulted in the cube and recrystallized β-fiber orientations after annealing. A two dimensional Monte
Carlo (MC) method was used to simulate primary recrystallization in gold sheet. A function of
boundary misorientation was introduced to consider anisotropic properties of grain boundary energy
and mobility. Stored energy associated with orientations in the deformed grains was evaluated by
reconstructing of data measured using electron back-scattered diffraction (EBSD). The nucleation at
an initial stage of recrystallization was found at the high angle grain boundaries (HAGBs) and grain
interiors. The main texture components obtained by the simulation were similar to those obtained
experimentally except cube component.
Abstract: A modified two dimensional (2-D) Monte Carlo (MC) technique was used to simulate
primary recrystallization in automotive steels containing fine particles. In order to consider
anisotropic properties of grain boundary energy and grain boundary mobility, functions of boundary
misorientation were introduced. Orientation-dependent stored energy developed in 80% cold-rolled
interstitial free (IF) sheet steel was evaluated by reconstructing of data measured using electron
back-scattered diffraction (EBSD) analysis. A subgrain method based on subgrain structure is used
for quantitative analysis of the stored energy. The simulation reveals that particles affect evolution of
microstructure during recrystallization. The simulation provided a theoretical foundation for
understanding effect of particles on the final microstructures and crystallographic textures.
Abstract: Oxygen-free high conductivity copper was subjected to room temperature equal channel
angular extrusion of 8 passes using route Bc. The resulting ultra-fine grain copper was then rolled to
thickness reductions of up to 96.5% at liquid nitrogen temperatures. Annealed coarse grained copper
was rolled to the same strain at room temperature for comparison. Samples from the two routes
were isochronally and isothermally annealed, and the microstructure and texture evolution studied
by electron back scattered diffraction and x-ray diffraction.
Annealing of the ultrafine grained copper led to the development of a strong rotated cube texture
from a texture in the rolled material dominated by the Brass component. In contrast the more
commonly observed cube texture was found after annealing of the coarse-grained sample.
Accompanying the rotated cube texture was the development of a large fraction of boundaries with
rotation angle/axis close to 60° <111>.
Abstract: Primary recrystallization textures were examined in the 84% and 95% cold-rolled boron-free Ni3Al single crystals with a Goss texture using the electron backscatter diffraction method. It was found that the main components of the textures in the specimens heat-treated at 873K/0.5h had a 40° rotation relationship about <111> to the original, Goss texture. All the eight variants of 40°<111> rotated grains existed. However, the number density is not even but dependent on whether the rotation axis is identical to the normal of slip planes activated during the prior cold rolling. The ratio of the number density among the variants was same in both the 84% and 95% cold-rolled foils. Based on these results, the formation of these 40°<111> rotated grains was explained assuming the modified multiple twinning mechanism where the annealing twinning occurred at the activated slip planes, followed by the subsequent twinning.
Abstract: The structure and properties of oxygen-free copper (99,98%) were studied after different
types of severe plastic deformation (SPD): equal-channel angular pressing (ECAP), multiaxial
deformation (MD), and accumulative roll bonding (ARB) as a function of the strain at room
temperature (to a true strain of 30-40). The SPD facilitates the formation of submicrocrystalline
structure with a grain size of 200-250 nm and predominantly high angle boundaries (83-94%). ECA
pressing leads to the formation of the most uniform submicrocrystalline structure.The strength
characteristics increase with increasing strain and reach the steady stage at ε ≈ 5. At the steady
stage, UTS = 460-480 MPa at ARB, and MD, while UTS at ECAP is somewhat lower, 430-440
MPa. The smallest "steady" values EL = 4 - 5% were obtained in the case of ARB, and the
maximum EL = 18% was obtained at MD.
Abstract: It is well known that the deformation and recrystallisation of metals and alloys are
accompanied by changes in texture and microstructure. These changes can lead to anisotropy in
metal flow and affect the formability of sheet metals. Therefore, a significant amount of research
on the development of textures and the principles governing them has been conducted in recent
years. One of the most important factors contributing to the texture development of materials is the
initial grain size. Unlike other factors such as stacking fault energy, strain and deformation
temperature, relatively little work has been carried out on the effect of grain size on texture
development, even though a considerable understanding exists regarding the effect of grain size on
work hardening and recrystallisation kinetics upon annealing. Hence, this research describes the
effect of the initial hot band grain size on the development of texture during cold rolling and
Abstract: The isochronal annealing behavior of nanostructured commercial purity aluminium
(AA1100 and AA1200) following either cold – rolling or accumulative roll bonding up to an ultra
high strain of εvM = 6.2 (99.5% reduction in thickness) has been studied via hardness testing and by
a microstructural investigation. A large effect of rolling strain is observed on the recovery at
temperatures below approx. 200 °C. At higher temperatures an assessment of the changes in
hardness and microstructure leads to a characterization of the annealing process as one of
conventional (discontinuous) recrystallization.