Texture Development in Cold Rolled and Annealed Ta

2011 ◽  
Vol 695 ◽  
pp. 153-157 ◽  
Author(s):  
Kuk Hyun Song ◽  
Han Sol Kim ◽  
Won Yong Kim
Keyword(s):  
Grain Size ◽  
Elevated Temperature ◽  
Annealing Temperature ◽  
High Vacuum ◽  
Surface Oxidation ◽  
Reduction Ratio ◽  
Texture Development ◽  
Fibre Texture ◽  
Annealed Material ◽  
Cold Rolled

In order to investigate the texture development in cold rolled and annealed tantalum (Ta), the present study was carried out. For this work, cold rolling was performed up to ~ 96% reduction in thickness, and annealing was performed at elevated temperature up to ~ 1200 °C for 60 min under the high vacuum to prevent the surface oxidation. As a result, increase in the reduction ratio of the cold rolled Ta was effective to develop the a fibre texture, with its texture components such as (001)<110> and (112)<110>. Also, resulting grain size was more refined by increase in reduction ratio, consequently, 96% cold rolled and annealed material showed the best refined grain size. However, in case of annealed material, g fibre texture with its texture component, such as (111)<121> and (111)<112>, was developed by increase in annealing temperature. In this study, we systematically discussed the texture development due to the increase in reduction ratio.

Recrystallisation Behaviour of an Fe-Mn-C-Si-Al TWIP

2012 ◽  
Vol 715-716 ◽  
pp. 649-654 ◽  
Author(s):  
Lieven Bracke ◽  
Nieves Cabañas-Poy
Keyword(s):  
Grain Size ◽  
Cold Rolling ◽  
Annealing Temperature ◽  
Twip Steel ◽  
Rolling Texture ◽  
Annealing Temperatures ◽  
Twip Steels ◽  
Cold Rolled ◽  
Main Components ◽  
Cold Rolling Texture

The static recrystallisation behaviour of cold rolled and annealed TWinning Induced Plasticity (TWIP) steels is important for its industrial production. The recrystallisation kinetics have been determined for an Fe-Mn-C-Si-Al TWIP steel using hardness measurements and microstructure analysis: it has been shown that recrystallisation progresses rapidly with increased annealing temperature. Recrystallisation was faster at higher cold reductions, and a smaller final grain size was observed at lower annealing temperatures. This indicates that the mechanism is nucleation dominated at lower temperatures; grain growth at higher temperatures appears similar for all reductions. The recrystallisation results in a crystallographic texture where the main components of the cold rolling texture are preserved in the final texture after annealing, although some randomisation was observed.

Development of Cube-Textured Ni and Ni-W Alloy Tapes by Focused Infrared Heating

2006 ◽  
Vol 510-511 ◽  
pp. 258-261
Author(s):  
Jun Ki Chung ◽  
Sung Yeal Bae ◽  
Sung Gap Lee ◽  
Chan Park ◽  
Sang Im Yoo ◽  
...  
Keyword(s):  
Grain Size ◽  
Critical Role ◽  
Texture Development ◽  
Infrared Heating ◽  
Halogen Lamp ◽  
Ir Heating ◽  
Heat Treated ◽  
Steep Temperature Gradient ◽  
Infrared Heater ◽  
Cold Rolled

We fabricated bi-axially textured pure Ni and Ni–5at.%W (Ni-5W) alloy tapes for the application of rechargeable battery cathode and coated superconductor, where the controlled microstructure of the substrate plays a critical role. The sintered Ni or Ni-W rods were cold-rolled into the thin tapes of 80 ~ 100 µm thickness, and the tapes were heat-treated for texture development with a line focused infrared heater. The temperature was maintained at 800 ~ 1050 °C, using a 1kW double ended linear halogen lamp in 96%Ar-4%H2 atmosphere. The (2 0 0) texture of Ni tape was successfully formed through optimization of the recrystallization infrared heating condition for the cold rolled Ni tapes. The full width half maximum of the Ni tapes was less than 10o, and the grain size was 20 ~ 40 µm. Focused IR-heating resulted in a better texture development and smaller grain size compared to the conventional resistive heating because of the steep temperature gradient.

Microstructure and Texture Development in Pure Ta Sheets Processed by Conventional Rolling and Cross Roll Rolling

2012 ◽  
Vol 706-709 ◽  
pp. 2652-2656 ◽  
Author(s):  
Kuk Hyun Song ◽  
Han Sol Kim ◽  
Won Yong Kim
Keyword(s):  
Effective Strain ◽  
High Vacuum ◽  
Diffraction Method ◽  
Vacuum State ◽  
Rolling Process ◽  
Texture Development ◽  
Experimental Result ◽  
Grain Boundary Character ◽  
Cold Rolled ◽  
Conventional Rolling

To evaluate the effect of rolling process on microstructures and textures development, this work was carried out using pure Ta sheets. For this work, conventional rolling (CR) and cross roll rolling (CRR) as a deformation process were introduced, pure Ta sheets were cold rolled to 90% in thickness reduction. After this, to obtain the recrystallized microstructure on cold rolled materials, the recrystallization heat-treatment was performed at 1200°C for 60 min under the high vacuum state. Also, to analyse the grain boundary character distributions of the annealed sheets, electron back-scattered diffraction method was introduced. As an experimental result, increase in strain rate led to the development of texture with its texture component of <111> at conventional rolling and cross roll rolling, in common. Therefore, in this study, we systematically discussed the texture development due to increase in effective strain.

Study on Evolution of Partial Texture of Different Grains during Grain Growth in IF Steels

2010 ◽  
Vol 638-642 ◽  
pp. 2799-2804 ◽  
Author(s):  
W.P. Tong ◽  
W.Y. Chen ◽  
Francis Wagner ◽  
L. Zuo ◽  
J.C. He
Keyword(s):  
Grain Size ◽  
Grain Growth ◽  
Annealing Temperature ◽  
Annealing Treatment ◽  
Steel Sample ◽  
Temperature Dependent ◽  
Experiment Data ◽  
Texture Characteristic ◽  
Mean Grain Size ◽  
Cold Rolled

An IF steel sample was cold rolled to a reduction of 80% and subsequently submitted to annealing treatment at 650°C, 710°C and 770°C for various durations, respectively. The grain size and evolution of partial texture of small, medium and large grains were investigated during grain growth. It was found that the growth rate and partial texture characteristic were absolutely distinct at different annealing temperature, both were temperature dependent. At same annealing temperature, partial texture for various annealing time was similar, but its intensity increases with an increment of duration. And the relation between partial texture of different grains assembly and its mean grain size can be expressed by an empirical formula from experiment data.

Microstructures and Shape Memory Characteristics of a Nanostructured Ti-50.0Ni(at%) Alloy

2008 ◽  
Vol 8 (2) ◽  
pp. 949-954
Author(s):  
Gyu-bong Cho ◽  
Yeon-ho Kim ◽  
Han-sung Kim ◽  
Ju-young Choi ◽  
Jung-moo Lee ◽  
...  
Keyword(s):  
Grain Size ◽  
Shape Memory ◽  
Grain Boundaries ◽  
Annealing Temperature ◽  
Cold Working ◽  
Scanning Calorimetry ◽  
Band Shape ◽  
Average Grain Size ◽  
Cold Rolled ◽  
Memory Characteristics

Nanostructured Ti-Ni alloys were prepared by cold working followed by annealing, and then their shape memory characteristics and superelasticity were investigated by means of differential scanning calorimetry (DSC), transmission electron microscopy (TEM), thermal cycling tests under constant load and tensile tests. Morphology of amorphous phases induced by cold working depended largely on the amount of cold working. They had domain like shape in the 40% cold rolled alloy, while had mainly wide band shape in the 70% cold rolled alloy. In 40% cold rolled alloy, the average grain size increased from 27 nm to 80 nm with increasing annealing temperature from 573 K to 673 K. Transformation elongation increases with raising annealing temperature, which was ascribed to the increase in grain size reducing the constraints of grain boundaries. Transformation hysteresis increased rapidly with raising annealing temperature up to 623 K, above which they almost keep constant, which was ascribed to the small grain size and large constraints of grain boundaries.

Growth of hematite by surface oxidation of olivine

1988 ◽  
Vol 46 ◽  
pp. 800-801
Author(s):  
S. McKernan ◽  
C. B. Carter
Keyword(s):  
Electron Microscope ◽  
Surface Oxidation ◽  
Thin Foil ◽  
Nucleation And Growth ◽  
Ion Milling ◽  
Annealed Material ◽  
Thin Foils ◽  
Natural Olivine ◽  
Approximate Composition ◽  
Second Phases

The oxidation of natural olivine has previously been performed on bulk samples and the reactions followed by preparation of TEM specimens from the annealed material. These results show that below ∼1000°C hematite and amorphous silica are formed, particularly around dislocations. At higher temperatures magnetite and some enstatite-like phase are formed. In both cases the olivine is left almost totally Fe depleted. By performing the oxidation on characterized thin TEM specimens it is possible to obtain more information on the nucleation and growth of the second phases formed. The conditions in a thin foil, however, are very different from those in the bulk especially with regard to surface effects. The nucleation of precipitates in particular may be expected to occur differently in these thin foils than in the bulk.TEM specimens of natural olivine (approximate composition Mg+Fe+Si2o4) which had been annealed at 1000°C for 1 hr were prepared by mechanical polishing and dimpling, followed by Ar ion milling to perforation. The specimens were characterized in the electron microscope and then heated in air in alumina boats to 900°C for between 30 and 180 minutes.

Slip traces caused by plastic deformation during recrystallization of thin metal sheets

1994 ◽  
Vol 52 ◽  
pp. 620-621
Author(s):  
H. Lin ◽  
D. P. Pope
Keyword(s):  
Grain Size ◽  
Grain Boundaries ◽  
Sample Thickness ◽  
List Type ◽  
Metal Sheets ◽  
Second Phases ◽  
Slip Traces ◽  
Series Of Experiments ◽  
Cold Rolled ◽  
Individual Grains

During a study of mechanical properties of recrystallized B-free Ni3Al single crystals, regularly spaced parallel traces within individual grains were discovered on the surfaces of thin recrystallized sheets, see Fig. 1. They appeared to be slip traces, but since we could not find similar observations in the literature, a series of experiments was performed to identify them. We will refer to them “traces”, because they contain some, if not all, of the properties of slip traces. A variety of techniques, including the Electron Backscattering Pattern (EBSP) method, was used to ascertain the composition, geometry, and crystallography of these traces. The effect of sample thickness on their formation was also investigated.In summary, these traces on the surface of recrystallized Ni3Al have the following properties:1.The chemistry and crystallographic orientation of the traces are the same as the bulk. No oxides or other second phases were observed.2.The traces are not grooves caused by thermal etching at previous locations of grain boundaries.3.The traces form after recrystallization (because the starting Ni3Al is a single crystal).4.For thicknesses between 50 μm and 720 μm, the density of the traces increases as the sample thickness decreases. Only one set of “protrusion-like” traces is visible in a given grain on the thicker samples, but multiple sets of “cliff-like” traces are visible on the thinner ones (See Fig. 1 and Fig. 2).5.They are linear and parallel to the traces of {111} planes on the surface, see Fig. 3.6.Some of the traces terminate within the interior of the grains, and the rest of them either terminate at or are continuous across grain boundaries. The portion of latter increases with decreasing thickness.7.The grain size decreases with decreasing thickness, the decrease is more pronounced when the grain size is comparable with the thickness, Fig. 4.8.Traces also formed during the recrystallization of cold-rolled polycrystalline Cu thin sheets, Fig. 5.

scholarly journals Microstructure and Mechanical Properties of Novel Quasibinary Al-Cu-Yb and Al-Cu-Gd Alloys

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 476
Author(s):  
Sayed Amer ◽  
Ruslan Barkov ◽  
Andrey Pozdniakov
Keyword(s):  
Mechanical Properties ◽  
Tensile Properties ◽  
Mechanism Of Action ◽  
Annealing Temperature ◽  
Eutectic Reaction ◽  
Solidification Process ◽  
Annealed State ◽  
Microstructure And Mechanical Properties ◽  
Cold Rolled ◽  
Hot Rolled

Microstructure of Al-Cu-Yb and Al-Cu-Gd alloys at casting, hot-rolled -cold-rolled and annealed state were observed; the effect of annealing on the microstructure was studied, as were the mechanical properties and forming properties of the alloys, and the mechanism of action was explored. Analysis of the solidification process showed that the primary Al solidification is followed by the eutectic reaction. The second Al8Cu4Yb and Al8Cu4Gd phases play an important role as recrystallization inhibitor. The Al3Yb or (Al, Cu)17Yb2 phase inclusions are present in the Al-Cu-Yb alloy at the boundary between the eutectic and aluminum dendrites. The recrystallization starting temperature of the alloys is in the range of 250–350 °C after rolling with previous quenching at 590 and 605 °C for Al-Cu-Yb and Al-Cu-Gd, respectively. The hardness and tensile properties of Al-Cu-Yb and Al-Cu-Gd as-rolled alloys are reduced by increasing the annealing temperature and time. The as-rolled alloys have high mechanical properties: YS = 303 MPa, UTS = 327 MPa and El. = 3.2% for Al-Cu-Yb alloy, while YS = 290 MPa, UTS = 315 MPa and El. = 2.1% for Al-Cu-Gd alloy.

LiNiO2 Thin Films Fabricated by Diffusion of Li on Ni Tapes

2007 ◽  
Vol 336-338 ◽  
pp. 505-508
Author(s):  
Cheol Jin Kim ◽  
In Sup Ahn ◽  
Kwon Koo Cho ◽  
Sung Gap Lee ◽  
Jun Ki Chung
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Grain Size ◽  
Sol Gel ◽  
Surface Oxidation ◽  
Cold Isostatic Pressing ◽  
Tube Furnace ◽  
Treatment Conditions ◽  
Average Grain Size ◽  
Cold Rolling And Annealing

LiNiO2 thin films for the application of cathode of the rechargeable battery were fabricated by Li ion diffusion on the surface oxidized NiO layer. Bi-axially textured Ni-tapes with 50 ~ 80 μm thickness were fabricated using cold rolling and annealing of Ni-rod prepared by cold isostatic pressing of Ni powder. Surface oxidation of Ni-tapes were conducted using tube furnace or line-focused infrared heater at 700 °C for 150 sec in flowing oxygen atmosphere, resulted in NiO layer with thickness of 400 and 800 μm, respectively. After Li was deposited on the NiO layer by thermal evaporation, LiNiO2 was formed by Li diffusion through the NiO layer during subsequent heat treatment using IR heater with various heat treatment conditions. IR-heating resulted in the smoother surface and finer grain size of NiO and LiNiO2 layer compared to the tube-furnace heating. The average grain size of LiNiO2 layer was 0.5~1 μm, which is much smaller than that of sol-gel processed LiNiO2. The reacted LiNiO2 region showed homogeneous composition throughout the thickness and did not show any noticeable defects frequently found in the solid state reacted LiNiO2, but crack and delamination between the reacted LiNiO2 and Ni occurred as the reaction time increased above 4hrs.

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