scholarly journals Torsion Texture Measurements With High-Energy Synchrotron Radiation on NiAl

2003 ◽  
Vol 35 (3-4) ◽  
pp. 163-173 ◽  
Author(s):  
W. Skrotzki ◽  
B. Klöden ◽  
R. Tamm ◽  
C.-G. Oertel ◽  
U. Garbe ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
High Pressure Torsion ◽  
Shear Plane ◽  
High Energy ◽  
Electron Back Scatter Diffraction ◽  
Large Strains ◽  
Shear Direction ◽  
Texture Formation ◽  
Local Texture ◽  
Pole Figures

Diffraction with high-energy synchrotron radiation is a new experimental method to determine textures of materials, which due to the special properties of this radiation, in the future may have advantages in terms of accuracy of local texture measurements in comparison to established methods like Electron back scatter diffraction (EBSD). In the present study NiAl polycrystals with two different initial textures have been deformed in torsion at 727°C and 1000°C and their texture development has been measured with highenergy synchrotron radiation. Torsion enables the study of texture formation with strain as well as the exploration of large strains without changing the shape of the samples. The pole figures indicate the preferred alignment of ‹100› with the shear direction and {110} with the shear plane. High pressure torsion may also open new possibilities in terms of grain refinement and texture formation and thus ductilization of NiAl.

Texture Gradient in ECAP Silver Measured by Synchrotron Radiation

2005 ◽  
Vol 495-497 ◽  
pp. 821-826 ◽  
Author(s):  
Werner Skrotzki ◽  
N. Scheerbaum ◽  
C.G. Oertel ◽  
Heinz Günter Brokmeier ◽  
Satyam Suwas ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Neutron Diffraction ◽  
Room Temperature ◽  
Extrusion Direction ◽  
High Energy ◽  
Texture Gradient ◽  
Fcc Metals ◽  
Local Texture ◽  
Angular Pressing ◽  
Global And Local

Silver of 3N purity was deformed at room temperature by equal channel angular pressing (ECAP) using three passes of route A. The global and local texture were investigated by neutron diffraction and high-energy synchrotron radiation, respectively. The texture is characterized by typical simple shear components of fcc metals which differently deviate from their ideal positions. Local texture measurements reveal that the intensity and inclination of the texture components with respect to the extrusion direction depend on the distance from the top of the extruded bar and change from pass to pass. Reasons for the texture gradient are discussed. The texture of silver is compared with that of copper having a higher stacking fault energy.

Texture Evolution of HPT-Processed Ni50Mn29Ga21

2011 ◽  
Vol 702-703 ◽  
pp. 169-172 ◽  
Author(s):  
Robert Chulist ◽  
Andrea Böhm ◽  
E. Rybacki ◽  
T. Lippmann ◽  
C.G. Oertel ◽  
...  
Keyword(s):  
High Pressure ◽  
Hydrostatic Pressure ◽  
Synchrotron Radiation ◽  
High Pressure Torsion ◽  
Electron Backscatter Diffraction ◽  
Texture Evolution ◽  
Residual Austenite ◽  
High Energy ◽  
Electron Backscatter ◽  
Backscatter Diffraction

The texture of polycrystalline Ni50Mn29Ga21alloys fabricated by high pressure torsion (HPT) was investigated with high-energy synchrotron radiation. HPT was performed at temperatures between 873K and 1173K under a hydrostatic pressure of 400 MPa. During HPT above 973K the initial cyclic fibre texture changes to a strong cube and a weak F component. Below 973K a strong rotated cube and weak F and C components develop. Additionally, electron backscatter diffraction reveals that samples deformed at low temperature do not completely transform to martensite giving rise to residual austenite.

Texture and microstructure imaging in six dimensions with high-energy synchrotron radiation

2003 ◽  
Vol 36 (5) ◽  
pp. 1240-1255 ◽  
Author(s):  
Hans Joachim Bunge ◽  
Leszek Wcislak ◽  
Helmut Klein ◽  
Ulf Garbe ◽  
Jochen Richard Schneider
Keyword(s):  
Synchrotron Radiation ◽  
Imaging Techniques ◽  
High Energy ◽  
Resolving Power ◽  
Step Width ◽  
Area Detector ◽  
New Methods ◽  
Pole Figures ◽  
Finite Step ◽  
High Orientation

The texture of a material can be calculated from several pole figures, which, in turn, are usually measured by one of several `step-scan' techniques. In these techniques, the finite step width limits the attainable orientation resolving power. In the present paper, the discontinuous step-scan technique is replaced by a continuous `sweeping' technique based on the continuous movement of an area detector during exposure. In this way, continuous two-dimensional `images' of pole figures are obtained, without the necessity of interpolation. Similar sweeping techniques are also being used to obtain continuous images of other sections and projections of the six-dimensional `orientation–location' space which characterizes a polycrystalline structure completely. The high potential orientation and/or location resolving power of these imaging techniques can only be reached with synchrotron radiation. In the present paper, the measurements were made at the high-energy (short-wavelength) beamline BW5 at HASYLAB/DESY in Hamburg. The high orientation and location resolving power implies the necessity to distinguish `grain-resolved' textures and microstructures (mainly in recrystallized materials) from `continuous' ones (mainly in deformed materials). Under certain conditions, it is thus possible to obtain the complete six-dimensional `orientation stereology' of grain-resolved microstructures. The new methods are illustrated with several examples, including technological applications.

Peculiarities in the Texture Formation of Intermetallic Compounds Deformed by High Pressure Torsion

2014 ◽  
Vol 1760 ◽  
Author(s):  
Christine Tränkner ◽  
Aurimas Pukenas ◽  
Jelena Horky ◽  
Michael Zehetbauer ◽  
Werner Skrotzki
Keyword(s):  
High Pressure ◽  
High Pressure Torsion ◽  
Electron Backscatter Diffraction ◽  
High Energy ◽  
X Ray ◽  
Local Texture ◽  
Large Rotations ◽  
Electron Backscatter ◽  
Shear Strains ◽  
Backscatter Diffraction

ABSTRACTNiAl, YCu and TiAl polycrystals with B2 and L10 structure, respectively, have been deformed by high pressure torsion (HPT) at temperatures between 20°C and 500°C at a hydrostatic pressure of 8 GPa to high shear strains. Local texture measurements were done by diffraction of high-energy synchrotron radiation and X-ray microdiffraction. In addition, the microstructure was analyzed by electron backscatter diffraction (EBSD). Besides typical shear components an oblique cube component is observed with quite large rotations about the transverse direction. Based on the temperature dependence of this component as well as on microstructure investigations it is concluded that it is formed by discontinuous dynamic recrystallization. The influence of high pressure on recrystallization of intermetallics at low temperatures is discussed.

Application of high-energy synchrotron radiation for texture studies

2000 ◽  
Vol 33 (2) ◽  
pp. 364-371 ◽  
Author(s):  
O. V. Mishin ◽  
E. M. Lauridsen ◽  
N. C. Krieger Lassen ◽  
G. Brückner ◽  
T. Tschentscher ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Plate Thickness ◽  
High Energy ◽  
X Ray Diffraction ◽  
Good Qualitative Agreement ◽  
Shear Texture ◽  
X Ray ◽  
Number Of Layers ◽  
Pole Figures ◽  
Cold Rolled

A novel experimental technique that employs high-energy synchrotron radiation is used for the investigation of through-thickness texture gradients in two aluminium plates, cold-rolled 40% with either intermediate or small draughts. In these two plates, crystallographic textures are inspected in a large number of layers. Texture maps of pole densities throughout the sample thickness are presented. A texture of the rolling type is developed through the plate thickness after intermediate draught rolling. Pronounced inhomogeneities associated with the shear texture are observed in the sample rolled with small draughts. For selected layers, direct pole figures are compared with those obtained by traditional low-energy X-ray diffraction and by the electron backscattering pattern technique using a scanning electron microscope. A good qualitative agreement between textures measured using the three different techniques is obtained. Experimental aspects and potentials of the new technique are discussed.

Formation of Substructure and Texture in Dual-Phase Steels due to Thermal Treatment

2010 ◽  
Vol 160 ◽  
pp. 147-152
Author(s):  
M. Masimov ◽  
Helmut Klein
Keyword(s):  
Synchrotron Radiation ◽  
Thermal Treatment ◽  
High Energy ◽  
Dual Phase ◽  
Texture Formation ◽  
X Ray ◽  
Dp Steels ◽  
Initial Texture ◽  
Bcc Phase ◽  
Ray Methods

Microstructure and texture formation in DP steels obtained by thermal treatment at temperatures of 780 °C i.e. between Ac1 and Ac3 and at 900 °C, i.e. above Ac3 and following different cooling techniques were studied by means of X-ray and electron diffraction techniques. The formation of the different structure constituents as well as substructure parameters such as blocks size and misorientation between them induced by thermal treatment was detailed analyzed. Various methods – conventional X-ray methods, high-energy synchrotron radiation and EBSD measuring – the texture of the bcc phase were applied in order to investigate their influence on the results. Beside texture heredity, a softening of the initial texture components induced by cold rolling and of related anisotropy of steels due to thermal treatment was estimated.

Shear Texture Formation during High-Strain Torsion of Titanium Aluminides

2005 ◽  
Vol 105 ◽  
pp. 303-308 ◽  
Author(s):  
G.H. Cao ◽  
Burghardt Klöden ◽  
C.G. Oertel ◽  
Werner Skrotzki ◽  
U. Garbe ◽  
...  
Keyword(s):  
Titanium Aluminides ◽  
Constant Strain Rate ◽  
Shear Plane ◽  
High Energy ◽  
Shear Direction ◽  
Shear Texture ◽  
Globular Structure ◽  
Fine Grained ◽  
Grain Structures ◽  
Transmission Electron

Ti-47Al-4(Cr, Nb, Mn, B) samples with different initial grain structures and fibre textures were deformed in torsion at 1000 °C under hydrostatic pressure of 400 MPa in a Paterson type rock deformation machine at a maximum constant strain rate of 2*10-4 s-1. The microstructure was investigated by transmission electron microscopy (TEM). Local texture measurements as a function of shear strain were done with high-energy synchrotron radiation. During shearing due to dynamic recrystallization the initially lamellar structure breaks down into a fine-grained globular structure with a g grain size in the order of 5 µm. The shear texture developed consists of <110> and {110} inclined to the shear direction and shear plane, respectively. The microstructure and texture development is discussed.

Local Texture Measurements with High-Energy Synchrotron Radiation on NiAl Deformed in Torsion

2002 ◽  
Vol 408-412 ◽  
pp. 161-166
Author(s):  
Werner Skrotzki ◽  
R. Tamm ◽  
Burghardt Klöden ◽  
C.G. Oertel ◽  
L. Wcislak ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
High Energy ◽  
Local Texture

Influence of Dynamic Recrystallisation on Texture Formation in ECAP deformed Nickel

2007 ◽  
Vol 558-559 ◽  
pp. 575-580 ◽  
Author(s):  
Werner Skrotzki ◽  
Burghardt Klöden ◽  
I. Hünsche ◽  
Robert Chulist ◽  
Satyam Suwas ◽  
...  
Keyword(s):  
Orientation Imaging Microscopy ◽  
High Energy ◽  
Texture Gradient ◽  
Texture Formation ◽  
Microstructure Formation ◽  
Fcc Metals ◽  
Orientation Imaging ◽  
Angular Pressing ◽  
Dynamic Recrystallisation ◽  
Number Of Passes

3N nickel has been deformed by equal channel angular pressing (ECAP) at 400°C up to 3 passes using route A. The texture with respect to position in the deformed billet, i.e. from top to bottom, has been measured with high-energy synchrotron radiation. It is characterized by texture components typical for simple shear in the intersection plane of the square-shaped 90° bent channel. Besides, an oblique cube component is observed. Orientation imaging microscopy clearly shows that this component is due to partial recrystallization. Intensities of the texture components as well as deviations from their ideal shear positions vary from the top to the bottom of the billet and with the number of passes. The change of the intensity of texture components and the texture gradient investigated is discussed. Special emphasis is put on the influence of dynamic recrystallization on texture and microstructure formation during ECAP of fcc metals.

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