Recrystallization Texture of Heavily Cold Rolled Polycrystalline Nickel Sheets with and without Strong Starting Cube Texture

2013 ◽  
Vol 753 ◽  
pp. 293-296 ◽  
Author(s):  
Pinaki Prasad Bhattacharjee ◽  
Yoshihiro Takatsuji ◽  
Yoji Miyajima ◽  
Daisuke Terada ◽  
Nobuhiro Tsuji

The evolution of texture is studied in high purity (~99.7%) nickel sheets with widely different starting cube texture ({001}) intensities following heavy cold rolling and annealing. For this purpose two nickel sheets with strong and weak starting recrystallization cube texture (SSCT and WSCT, respectively) prepared by Accumulative Roll Bonding and conventional rolling, respectively, followed by annealing are used as the starting materials for subsequent processing. These sheets are cold rolled to 90% reduction in thickness and annealed at different temperatures. Profuse cube oriented bands could be identified in the SSCT nickel sheet after 90% cold rolling as opposed to rather insignificant presence of cube regions in the WSCT nickel sheet. However, the WSCT nickel sheets consistently show stronger cube texture after annealing treatments as compared to the SSCT material. The failure to observe recrystallization cube texture in SSCT is attributed to the inhibited nucleation of cube grains owing to the unfavorable misorientation environment surrounding cube regions in the deformed matrix.

2006 ◽  
Vol 503-504 ◽  
pp. 711-716 ◽  
Author(s):  
Margarita Slámová ◽  
Petr Homola ◽  
P. Sláma ◽  
Jakub Čížek ◽  
Ivan Procházka ◽  
...  

It is known that the severe plastic deformation (SPD) induced by Accumulative Roll Bonding (ARB) results in more important grain refinement as compared to conventional rolling. Since ARB enables production of large amounts of ultra-fine grained (UFG) materials, its adoption into industrial practice is favoured. The paper presents the results of a study of high purity aluminium processed by ARB and cold rolling. Microstructure changes induced by both methods were studied by light and transmission electron microscopy. Dislocation density and arrangement were assessed by positron annihilation spectroscopy. Strength evolution was estimated by hardness measurements. Texture measurements were performed by X-ray diffraction. ARB processing results in over twofold increase in hardness. Hardness increases significantly after two ARB cycles and it raises only a little or decreases during subsequent cycles. The increase in hardness induced by conventional rolling is smaller. Positron lifetime measurements reveal a substantial increase of dislocation density at the first ARB cycle and a moderate increase or even a decrease at further cycles. The high fraction of positrons trapped at grain-boundary dislocations gives evidence for substantial grain refinement confirmed by TEM examinations. Grain size of 1.2 􀁐m in the rolling plane and as small as of 90 nm in the normal direction is obtained. The rolled samples have a typical rolling texture (􀁅-fibre). The 􀁅- fibre of the sample ARB processed to strain of 2.4 is weaker as compared to its rolled counterpart and it presents through thickness variations. The surface layers do not have any 􀁅-fibre orientations but they have ND-rotated cube texture formed by the shear strains induced by lubricant-free rolling.


2011 ◽  
Vol 702-703 ◽  
pp. 406-410
Author(s):  
Pinaki Prasad Bhattacharjee ◽  
Nobuhiro Tsuji

The effect of ultrahigh straining on the evolution of cube texture in high purity nickel (99.97%) processed by Accumulative Roll Bonding (ARB) is investigated in the present study. Fully recrystallized nickel sheet having average grain size of 28 μm is deformed by ARB to the strain levels of εeq=3.2 and εeq=6.4 corresponding to 4 and 8 cycles of ARB processing, respectively, and subsequently annealed at different temperatures. The 8 cycle ARB processed material consistently shows much higher cube volume fraction as compared to the 4 cycle processed material after different annealing treatments. Almost 100% cube volume could be obtained in the 8 cycle processed material after annealing at 800°C. The development of extremely sharp cube texture in the 8 cycle processed material could be attributed to the oriented nucleation of cube grains at early stages of recrystallization and subsequent growth of these grains. The results indicate that ultrahigh straining could be useful for applications requiring near perfect cube texture such as substrates for coated superconductors applications.


2012 ◽  
Vol 535-537 ◽  
pp. 615-619 ◽  
Author(s):  
Jinlong Liu ◽  
Yu Hui Sha ◽  
Yong Chuang Yao ◽  
Fang Zhang ◽  
Liang Zuo

The 4.2wt.%Si non-oriented electrical steel thin sheets with the thickness of 0.30mm were produced by the conventional procedure including hot rolling, cold rolling and annealing. The recrystallization texture was analyzed with emphasis on the effect of normalizing annealing. The results show that the  fiber with peak at {111} is weaker and η fiber is stronger in the sheets with normalizing annealing than those without normalizing annealing, either under the cold rolled reduction of 77% or 86%. Effects of normalizing annealing on the recrystallization texture can be explained in terms of the characteristic of the shear bands formed during cold rolling process.


2005 ◽  
Vol 495-497 ◽  
pp. 603-608 ◽  
Author(s):  
Atsushi Todayama ◽  
Hirosuke Inagaki

On the basis of Taylor-Bishop-Hill’s theory, many previous theoretical investigations have predicted that, at high rolling reductions, most of orientations should rotate along theβfiber from {110}<112> to {123}<634> and finally into the {112}<111> stable end orientations. Although some exceptions exist, experimental observations have shown, on the other hand, that the maximum on the β fiber is located still at about {123}<634> even after 97 % cold rolling. In the present paper, high purity Al containing 50 ppm Cu was cold rolled up to 99.4 % reduction in thickness and examined whether {112}<111> stable end orientation could be achieved experimentally. It was found that, with increasing rolling reduction above 98 %, {110}<112> decreased, while orientations in the range between {123}<634> and {112}<111> increased, suggesting that crystal rotation along the βfiber from {110}<112> toward {123}<634> and {112}<111> in fact took place. At higher rolling reductions, however, further rotation of this peak toward {112}<111> was extremely sluggish, and even at the highest rolling reduction, it could not arrive at {112}<111>. Such discrepancies between theoretical predictions and experimental observations should be ascribed to the development of dislocation substructures, which were formed by concurrent work hardening and dynamic recovery. Since such development of dislocation substructures are not taken into account in Taylor-Bishop-Hill’s theory, it seems that they can not correctly predict the development of rolling textures at very high rolling reductions, i. e. stable end orientations. On annealing specimens rolled above 98 % reduction in thickness, cube textures were very weak, suggesting that cube bands were almost completely rotated into other orientations during cold rolling. {325}<496>, which lay at an intermediate position between {123}<634> and {112}<111> along theβfiber, developed strongly in the recrystallization textures.


2020 ◽  
Vol 56 (1) ◽  
pp. 89-97
Author(s):  
I. Angela ◽  
I. Basori ◽  
B.T. Sofyan

Al-brass alloys (Cu29.5Zn2.5Al wt. %) were produced by gravity casting and homogenized at 800?C for 2 h, resulting in a binary phase morphology identified as cubic ? and martensitic ?? phases through X-ray diffraction (XRD). Samples were then subsequently cold rolled and annealed at 150, 300, 400, and 600?C for 30 minutes. Visible traces of slip, intersecting slip bands, and shear bands were observed in microstructure images of the samples after each progressive deformation stage. Deformation-induced martensites were present after 20 % cold rolling. Higher thickness reduction resulted in simultaneous strain hardening of the phases. Low temperature annealing slightly increased microhardness, of both ? and ??, due to the formation of precipitates. SEM-EDX analysis showed that no solute segregation was found in annealed samples. Annealing at higher temperature resulted in conventional softening. Recrystallized equiaxed ?? phase grains were visible after annealing at 600?C.


2013 ◽  
Vol 753 ◽  
pp. 285-288
Author(s):  
Feng Xiang Lin ◽  
Torben Leffers ◽  
Wolfgang Pantleon ◽  
Dorte Juul Jensen

Recrystallization kinetics in copper cold-rolled to 90% reduction with and without significant widening was investigated by electron backscatter diffraction. It was found that the recrystallization process was slightly retarded and the development of cube recrystallization texture was largely inhibited in the widening sample. Cube grains were observed to have a growth advantage by a factor of 2 in the non-widening sample, while this growth advantage was not observed in the widening sample. The recrystallization kinetics and the development of cube texture in the two samples are discussed.


2016 ◽  
Vol 854 ◽  
pp. 16-21 ◽  
Author(s):  
Anett Stöcker ◽  
Armin Franke ◽  
Harti Hermann ◽  
Rudolf Kawalla

In this paper the microstructure evolution of an iron-silicon alloy with 3.2 wt.% silicon throughout the manufacturing stages hot rolling, cold rolling and annealing is presented. Starting with a 35 mm thick feedstock, which was hot rolled to 1 mm, with different cooling conditions, the material was cold rolled to a final thickness of 0.3 mm and final annealed under same conditions to show the influence of the hot rolling on the texture and microstructure of the final annealed material.


Nanomaterials ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 540 ◽  
Author(s):  
Hanyu Hui ◽  
Re Xia ◽  
Juying Li ◽  
Qingsong Mei ◽  
Ye Ma ◽  
...  

The properties of nanoporous gold (NPG) were known to be dependent on the microstructure of NPG. In this study, the effects of cold rolling and annealing of the original Ag0.7Au0.3 alloy on the microstructure of NPG produced by dealloying under free corrosion condition were investigated. Ag0.7Au0.3 alloy samples were cold-rolled to different strain levels/thickness reductions up to 98% and annealed at 900 °C for 3 h before dealloying. It was found that cold rolling and annealing of the original alloy can lead to reduced ligament and pore sizes of NPG. Moreover, post-deformation annealing of the original alloy was found to facilitate the formation of a homogeneous and continuous NPG structure. The minima of pore and ligament sizes (both being ~8 nm) with uniform distribution were obtained in the annealed sample with a thickness reduction of 60% for a dealloying time of 7 h. The present study indicated the significant effect of a pre-dealloying treatment of the original alloy (by plastic deformation and annealing) on the formation and optimization of the NPG microstructure produced by dealloying.


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