Cold-rolling of Ti-rich TiAl polysynthetically twinned crystals

1990 ◽  
Vol 5 (3) ◽  
pp. 484-487 ◽  
Author(s):  
S. R. Nishitani ◽  
M. H. Oh ◽  
A. Nakamura ◽  
T. Fujiwara ◽  
M. Yamaguchi
Keyword(s):  
Cold Rolling ◽  
Shear Deformation ◽  
Surface Texture ◽  
Room Temperature ◽  
Stoichiometric Composition ◽  
Rolling Direction ◽  
Rolling Plane ◽  
Total Reduction ◽  
Pole Figures

Polysynthetically twinned crystals of TiAl with a nearly stoichiometric composition have been grown and rolled at room temperature. The maximum total reduction in thickness which is attainable without fracture depends on lamellae orientation with respect to the rolling plane and rolling direction. When specimens are oriented such that shear deformation parallel to the lamellar planes is operative during rolling and its operation causes lengthening of specimens, such specimens can be rolled up to about 50% reduction in thickness. The (111) pole figures are determined for the surface of specimens rolled to several different amounts of reduction, and the formation of surface texture is briefly discussed.

Neutron Diffraction Texture Analysis of Grain-Oriented Steel Sheets

2005 ◽  
Vol 105 ◽  
pp. 175-180 ◽  
Author(s):  
Stanislav Vratislav ◽  
Maja Dlouhá ◽  
Ladislav Kalvoda
Keyword(s):  
Neutron Diffraction ◽  
Cold Rolling ◽  
Texture Analysis ◽  
Volume Fraction ◽  
Rolling Direction ◽  
Orthorhombic Symmetry ◽  
Automatic Data ◽  
Cubic Symmetry ◽  
Steel Sheets ◽  
Pole Figures

Our laboratory developed and tested experimental and calculation techniques for quantitative texture analysis based on the ODF combined with the diffraction of thermal neutrons. In our work the texture of the Fe-3%Si sheets was investigated after different stages of their processing, i.e. hot-rolled strips, first cold rolling, first inter-annealing, second cold rolling, second annealing and secondary recrystallisation. The texture experiments were carried out on the KSN-2 diffractometer which is equipped with the TG-1 texture goniometer with automatic data collection for transmission and reflection geometry. TODFND (the cubic symmetry of the crystals and orthorhombic symmetry of the specimen) was used and the ODF values were obtained together with all texture characteristics (pole figures, inverse pole figures, ODF - f (g) values, fibre texture with <110> and <001> axis parallel to rolling direction, parameters of the ideal orientations (HKL)<uvw>, texture index J, volume fraction coefficient f. The comparison of the texture parameters of the six samples with the different technologic history is given and the magnetic anisotropy of all measured samples was determined by means of the quantitative texture analysis (ODF-the matrix Cl nµ) for all samples. Results achieved in our study confirm that the quantitative texture analysis in connection with neutron diffraction can help to improve the technology of the preparation of oriented magnetic steel sheets.

scholarly journals Effects of Initial Precipitate on Shear Deformation during Asymmetric Rolling of Al-Mg-Si Alloy: Texture and Formability

2020 ◽  
Vol 58 (10) ◽  
pp. 703-714
Author(s):  
Wonkee Chae ◽  
Bong-Kyu Kim ◽  
Jongbeom Lee ◽  
Jun Hyun Han
Keyword(s):  
Shear Deformation ◽  
Room Temperature ◽  
Tensile Deformation ◽  
Texture Evolution ◽  
Plastic Anisotropy ◽  
Rolling Direction ◽  
Strain Ratio ◽  
Equivalent Strain ◽  
Asymmetric Rolling ◽  
Plastic Strain Ratio

Al-Mg-Si alloy was rolled asymmetrically at several temperatures to apply shear deformation, and the effects of the initial precipitate on shear deformation, texture evolution, formability, and plastic anisotropy were studied. Texture was analyzed using a EBSD, and the formability and plastic anisotropy of the specimen were evaluated using the value and value calculated from the plastic strain ratio (r-value) which was determined from the change in the length of the specimen during tensile deformation. Asymmetric rolling induces a larger equivalent strain than symmetric rolling, and the equivalent strain increases as the asymmetric rolling temperature increases. When a specimen with peak-aged initial precipitates was asymmetrically rolled, less shear deformation occurred at room temperature than in a solution-treated specimen without initial precipitates. In contrast, a larger shear deformation occurred at high temperatures (500°C). With asymmetric rolling at room temperature, the specimens without initial precipitates had higher formability and lower plasticity, while for asymmetric rolling at high temperature, the specimens with initial precipitates had higher formability and lower plastic anisotropy. This is due to the <111>//ND texture, such as {111}<110> and {111}<112> orientation that has similar and high r-values at 0°, 45°, and 90° to the rolling direction, developed by the shear deformation that occurred during asymmetric rolling.

scholarly journals Deformation Zone Geometry and Texture Gradients in Cold-Rolled Niobium

1977 ◽  
Vol 2 (3) ◽  
pp. 183-203 ◽  
Author(s):  
R. A. Vandermeer ◽  
J. B. Bernal
Keyword(s):  
Deformation Zone ◽  
Room Temperature ◽  
Contact Length ◽  
Theoretical Explanation ◽  
Thickness Direction ◽  
X Ray ◽  
Total Reduction ◽  
Pole Figures ◽  
Cold Rolled ◽  
The Mean

Several niobium plates were cold-rolled at room temperature to a total reduction of 60% maintaining the geometry of the zone of deformation constant for each plate. Pole figures were obtained by means of the Schulz x-ray reflection technique from various depths in the thickness direction for plates rolled with different ∆, the ratio of the mean height of the deformation zone to its contact length. Severe texture gradients were noted and characterized for Δ>1; a modified texture different from the normal texture was observed at intermediate through-the-thickness locations. Both lateral widening and microhardness gradients were also in evidence for this case. No previously proposed theoretical explanation could account for these results.

On {h,1,1}, the Recrystallisation Texture of Heavily Cold Rolled BCC Steel

2004 ◽  
Vol 467-470 ◽  
pp. 269-274 ◽  
Author(s):  
Hotaka Homma ◽  
Shuichi Nakamura ◽  
Naoki Yoshinaga
Keyword(s):  
Grain Boundary ◽  
Cold Rolling ◽  
Single Crystal ◽  
Grain Boundaries ◽  
Rolling Direction ◽  
Experimental Results ◽  
Rolled Steel ◽  
Fibre Structure ◽  
Pole Figures ◽  
Cold Rolled

Heavily cold rolled BCC steel has been indicated to generate {411}<148> recrystallisation texture and its family orientations which might be represented as {h,1,1}<1/h,1,2>. As a-fibre structure, or RD//<011> texture is significantly developed during the cold rolling, it is naturally speculated to be the recrystallisation site of {h,1,1}<1/h,1,2> fibre. The present paper prompts to demonstrate the recrystallisation procedure by utilising EBSP-OIM analysis. The first demonstration was carried out with OIM analysis on partially recrystallised cold rolled steel. At the stage of 50% recrystallisation, only ND//<111> texture has appeared for the recrystallised area. {100}<011> - {211}<011> a-fibre remains as deformed structure, and several {h,1,1}<1/h,1,2> grains could be found at the grain boundaries. Therefore, a bi-crystal of {100}<011> was employed to simulate the irregular deformation at the grain boundary. After cold rolling, a warp toward the grain boundary was observed. Although the interior of the {100}<011> single crystal was hardly recrystallised, sharp {411}<148> texture was created along the grain boundary. In order to confirm the phenomenon, another experiment was carried out that a cold rolled {100}<011> single crystal was bent along the rolling direction and annealed. Very sharp {411}<148> recrystallisation texture was formed again at the bent perimeter. These experimental results lead us to conclude that the irregular strain was sufficiently piled at the grain boundary after the heavy deformation and generates {h,1,1}<1/h,1,2> texture. On {100} pole figures, the recrystallisation textures were equivalently scattered around three <100> poles, therefore the rotation relationship around <111> axes with the original orientation was suggested.

Cast and Rolling Textures of NiMnGa Alloys

2007 ◽  
Vol 1050 ◽  
Author(s):  
Robert Chulist ◽  
Martin Poetschke ◽  
Andrea Boehm ◽  
Heinz-Guenter Brokmeier ◽  
Ulf Garbe ◽  
...  
Keyword(s):  
Recrystallization Texture ◽  
Room Temperature ◽  
Rolling Direction ◽  
High Energy ◽  
Growth Direction ◽  
Rolling Plane ◽  
Variant Selection ◽  
Directionally Solidified ◽  
Magnetic Shape Memory ◽  
Hot Rolled

AbstractThe texture of two polycrystalline NiMnGa magnetic shape memory alloys fabricated by directional solidification and hot rolling has been measured with high-energy synchrotron radiation and neutron diffraction. At room temperature the alloys used are composed of a modulated (7M) and non-modulated (NM) martensitic structure. The texture of the directionally solidified alloy for all phases is a pronounced fibre texture with <100> preferentially aligned along the growth direction. In the directionally solidified case a variant selection took place with [001] dominating. The texture of the hot rolled alloy shows a weak recrystallization texture with {111} and <112> aligned parallel to the rolling plane and rolling direction, respectively. The texture results are discussed with respect to material, processing and phase transformations including variant selection.

Cold-Rolling and Subsequent Annealing of Ti-Rich Tial Polysynthetically Twinned (PST) Crystals

1990 ◽  
Vol 213 ◽  
Author(s):  
M.H. Oh ◽  
H. Inui ◽  
S.R. Nishitani ◽  
M. Yamaguchi
Keyword(s):  
Dislocation Density ◽  
Cold Rolling ◽  
Shear Deformation ◽  
Lamellar Structure ◽  
Room Temperature ◽  
Subsequent Annealing ◽  
Second Stage ◽  
Cold Rolled ◽  
Two Stages ◽  
Equiaxed Grains

ABSTRACTPolysynthetically twinned (PST) crystals of Ti-rich TiAl have been grown and specimens cut from these crystals have been rolled at room temperature and subsequently annealed at 900°C and 1000°C. When the shear deformation parallel to the lamellar boundaries occurs during rolling, PST crystals of Ti-rich TiAl can be rolled to about 50% reduction in thickness at room temperature.The recovery in microhardness occurs in two stages; the first stage associated with the decrease in dislocation density and the second stage connected with the annealing-out of deformation induced twins. The recrystallization mode depends on the amount of reduction. Up to 20% reduction, the lamellar structure is preserved even after the full recovery in hardness. When the amount of reduction exceeds 40%, a structure composed of equiaxed grains of TiAl is obtained after recrystallization. A mechanism of recrystallization of cold-rolled PST crystals, which may explain the dependence of recrystallization mode on the amount of reduction, is proposed.

Investigation of Mechanical Properties of Nanostructured Titanium Processed by Warm ECAP Followed Cold Rolling

2014 ◽  
Vol 875-877 ◽  
pp. 63-67 ◽  
Author(s):  
Dinh van Hai ◽  
Nguyen Trong Giang
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Cold Rolling ◽  
Room Temperature ◽  
Pure Titanium ◽  
Rolling Process ◽  
Coarse Grain ◽  
Nanostructured Titanium

In this work, ECAP technique was combined with cold rolling process in order to enhance mechanical properties and microstructure of pure Titanium. Coarse grain (CG) Titanium with original grain size of 150 μm had been pressed by ECAP at 425oC by 4, 8 and 12 passes, respectively. This process then was followed by rolling at room temperature with 35%, 55%, and 75% rolling strains. After two steps, mechanical properties such as strength, hardness and microstructure of processed Titanium have been measured. The result indicated significant effect of cold rolling on tensile strength, hardness and microstructure of ECAP-Titanium.

scholarly journals Influence of strain rate and heat treatments on tensile and creep properties of Zn-0.15Cu-0.07Ti alloys

DYNA ◽  
2016 ◽  
Vol 83 (195) ◽  
pp. 77-83 ◽  
Author(s):  
María José Quintana Hernández ◽  
José Ovidio García ◽  
Roberto González Ojeda ◽  
José Ignacio Verdeja
Keyword(s):  
Strain Rate ◽  
Room Temperature ◽  
Rolling Direction ◽  
Tensile Tests ◽  
Strain Rates ◽  
Creep Tests ◽  
Design Problems ◽  
Creep Properties ◽  
Heat Treated ◽  
Zn Alloys

The use of Cu and Ti in Zn alloys improves mechanical properties as solid solution and dispersoid particles (grain refiners) may harden the material and reduce creep deformation. This is one of the main design problems for parts made with Zn alloys, even at room temperature. In this work the mechanical behavior of a Zn-Cu-Ti low alloy is presented using tensile tests at different strain rates, as well as creep tests at different loads to obtain the value of the strain rate coefficient m in samples parallel and perpendicular to the rolling direction of the Zn strip. The microstructure of the alloy in its raw state, as well as heat treated at 250°C, is also analyzed, as the banded structure produced by rolling influences the strengthening mechanisms that can be achieved through the treatment parameters.

scholarly journals Sintesis dan Analisis Penambahan Doping Magnesium (Mg) pada Material Superkonduktor FeSe dengan Metode Reaksi Padatan dalam Tabung Tertutup

2019 ◽  
Vol 19 (2) ◽  
pp. 89-94
Author(s):  
Muhammad Ilham Maulana
Keyword(s):  
Room Temperature ◽  
Industrial Revolution ◽  
Stoichiometric Composition ◽  
Solid State Reaction Method ◽  
Superconducting Materials ◽  
Superconducting Material ◽  
Critical Temperature Tc ◽  
Properties Of Superconductors ◽  
Very High ◽  
Mg Doped

[ID] Ketergantungan manusia terhadap teknologi memasuki Revolusi Industri 4.0 sangat tinggi. Contoh penerapan inovasi di bidang teknologi informasi salah satunya adalah superkomputer dari material superkonduktor. Material superkonduktor identik dengan material non ferromagnetik karena sifatnya diamagnetis sempurna. Namun, sejak ditemukannya material superkonduktor berbasis logam ferromagnetik, penelitian terus dikembangkan, salah satunya material FeSe. Beberapa parameter yang perlu diperhatikan pada pembuatan material FeSe untuk memperoleh sifat superkonduktor terbaiknya diantaranya komposisi stoikiometri, penambahan doping, dan proses pembuatan material FeSe seperti proses pemaduan dan sintering. Dalam penelitian ini, pengaruh variasi doping Mg akan dianalisis terhadap sifat superkonduktor, morfologi, dan fasa yang terbentuk pada material superkonduktor FeSe. Material FeSe dibuat dengan metode reaksi padatan dalam tabung tertutup (Powder in Sealed Tube) secara insitu. Temperatur sintering yang digunakan 845⁰C yang ditahan selama 6 jam, dengan kenaikan temperatur 7⁰C/menit dari temperatur kamar, dan laju pendinginan normalizing. Kandidat material superkonduktor terbaik terdapat pada sampel Mg0.01Fe0.99Se. Didapatkan Temperatur kritis (Tc)onset = 15.42 K dan Tczero = 5.4 K. Morfologi sampel menunjukkan kristalisasi besar. Lalu, persentase fraksi volume fasa superkonduktornya juga merupakan yang terbesar yaitu 81.99%. [EN] Human dependence on technology into the Industrial Revolution 4.0 is very high. Example, the application of innovations in information technology is supercomputer from superconducting materials. Superconducting materials are identical from non-ferromagnetic materials because tend perfectly diamagnetic. However, since ferromagnetic-metal-based superconducting material discovered, research continues to be developed, like FeSe material. Some parameters that need to be considered in making FeSe material to obtain the best superconductor properties include stoichiometric composition, doping addition, and process of making FeSe materials like synthesis and sintering treatment. In this study, the effect of Mg-doped variations will be analyzed towards properties of superconductors, morphology, and phases formed in FeSe superconducting materials. MgxFe1-xSe made by solid-state reaction method in sealed tube (Powder in Sealed Tube) “insituely”. The sintering temperature used 845⁰C which held for 6 hours, with 7⁰C/minute temperature rise from room-temperature and normalizing cooling rate used. The best candidate superconducting material came from Mg0.01Fe0.99Se, obtained critical temperature (Tc)onset = 15.42 K, and Tczero = 5.4 K. Sample morphology shows a large crystallization. Then, the percentage fraction of the superconducting phase was also the largest, which is 81.99%.

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