Synchrotron texture analysis with area detectors

2003 ◽  
Vol 36 (4) ◽  
pp. 1040-1049 ◽  
Author(s):  
H.-R. Wenk ◽  
S. Grigull
Keyword(s):  
Texture Analysis ◽  
Standard Technique ◽  
Orientation Distribution ◽  
Polycrystalline Materials ◽  
Texture Measurement ◽  
X Ray ◽  
Texture Information ◽  
Reconstruction Methods ◽  
Special Cases ◽  
Wide Range

The wide availability of X-ray area detectors provides an opportunity for using synchrotron radiation based X-ray diffraction for the determination of preferred crystallite orientation in polycrystalline materials. These measurements are very fast compared to other techniques. Texture is immediately recognized as intensity variations along Debye rings in diffraction images, yet in many cases this information is not used because the quantitative treatment of texture information has not yet been developed into a standard technique. In special cases it is possible to interpret the texture information contained in these intensity variations intuitively. However, diffraction studies focused on the effects of texture on materials properties often require the full orientation distribution function (ODF) which can be obtained from spherical tomography analysis. In cases of high crystal symmetry (cubic and hexagonal) an approximation to the full ODF can be reconstructed from single diffraction images, as is demonstrated for textures in rolled copper and titanium sheets. Combined with area detectors, the reconstruction methods make the measurements fast enough to study orientation changes during phase transformations, recrystallization and deformationin situ, and even in real time, at a wide range of temperature and pressure conditions. The present work focuses on practical aspects of texture measurement and data processing procedures to make the latter available for the growing community of synchrotron users. It reviews previous applications and highlights some opportunities for synchrotron texture analysis based on case studies on different materials.

Application of Texture Analysis for Optimizing Thermo-Mechanical Treatment of a High Mn TWIP Steel

2014 ◽  
Vol 922 ◽  
pp. 213-218 ◽  
Author(s):  
Christian Haase ◽  
Luis Antonio Barrales-Mora ◽  
Dmitri A. Molodov ◽  
Günter Gottstein
Keyword(s):  
Cold Rolling ◽  
Texture Analysis ◽  
Twip Steel ◽  
Uniform Elongation ◽  
High Yield ◽  
Processing Route ◽  
Recrystallization Annealing ◽  
Deformation Degree ◽  
Texture Measurement ◽  
Wide Range

A recently introduced processing route consisting of cold rolling and recovery annealing allows the production of TWIP steels with high yield strength along with appreciable uniform elongation due to the thermal stability of mechanically induced nanoscale twins. A wide range of strength-ductility combinations was obtained using recovery and recrystallization annealing of 30%, 40%, and 50% cold-rolled Fe-23Mn-1.5Al-0.3C TWIP steel. Texture measurement during cold rolling and annealing was proven to be a suitable tool to determine the optimal deformation degree and annealing time for this processing method. As a consequence, texture analysis can be used to predict the final materials properties.

The Generalisation and Refinement of the Vector Method for the Texture Analysis of Polycrystalline Materials

1979 ◽  
Vol 23 ◽  
pp. 349-360 ◽  
Author(s):  
Daniel Ruer ◽  
Albert Vadon ◽  
Raymond Baro
Keyword(s):  
Experimental Data ◽  
Texture Analysis ◽  
Orientation Distribution ◽  
Polycrystalline Materials ◽  
Crystallite Orientation ◽  
Vector Method ◽  
Cubic Materials ◽  
First Time

AbstractA so-called “Vector Method” for the texture analysis of cubic materials was presented for the first time at this conference in 1976. Since then this method has been refined and applied successfully to non cubic-materials. It is shown in this paper that the Vector Method provides several advantages over series methods of texture analysis, the most important of which being the relatively small amount of experimental data which are needed for the determination of the entire crystallite orientation distribution.

Retrieving the configuration of grain boundary structure in polycrystalline materials by extraordinary X-ray reflection analysis

2020 ◽  
Vol 53 (4) ◽  
pp. 1006-1014
Author(s):  
Lorena Aarão-Rodrigues ◽  
Augusta Isaac ◽  
Roberto B. Figueiredo ◽  
Angelo Malachias
Keyword(s):  
Boundary Structure ◽  
Polycrystalline Materials ◽  
Nondestructive Monitoring ◽  
X Ray ◽  
Performance Space ◽  
Grain Boundary Structure ◽  
Wide Range ◽  
Angular Displacements ◽  
Microscopy Techniques ◽  
Interface Structures

The development of materials is strongly related to our capability of understanding thermal, mechanical and chemical processing on the nanoscale. Unravelling the interface structure is crucial for opening new regimes in property–performance space. Interface arrangements have been characterized by statistically limited microscopy techniques. In this work, a large-angular-range detector was used for synchrotron diffraction measurements on commercially pure Mg. Long acquisitions allowed the retrieval of preferred interface configurations through the observation of extraordinary diffraction peaks located close to the Mg 102, 200, 204 and 300 fundamental reflections. A kinematical simulation scanning possible interface structures established the correspondence of the non-bulk peaks to the interfacial organization of atoms that may be responsible for their appearance. Simulated interfaces were probed for a wide range of angular displacements with respect to the main cleavage planes. The results indicate configurations that allow the observation of X-ray diffraction, representing a long-range-ordered pattern of atomic distributions in Mg. The introduced methodology allows for nondestructive monitoring of systems that undergo processes that modify grain sizes and grain-interface orientation.

Application of quantitative texture analysis to Rietveld profile refinement of neutron diffraction patterns of a zircaloy sample

2001 ◽  
Vol 34 (3) ◽  
pp. 358-364 ◽  
Author(s):  
Y. C. Kim ◽  
B. S. Seong ◽  
J. H. Lee ◽  
E. J. Shin
Keyword(s):  
Neutron Diffraction ◽  
Texture Analysis ◽  
Rietveld Method ◽  
Structure Refinement ◽  
Polycrystalline Materials ◽  
Texture Information ◽  
Diffraction Patterns ◽  
The Individual ◽  
The Mathematical Model ◽  
Profile Refinement

The possibility of extending the Rietveld method to incorporate textured polycrystalline materials is demonstrated with a zircaloy sample. By assigning the pole densities obtained by separate texture analysis to the preferred orientation factors (POFs) in the mathematical model of the Rietveld method, good profile refinement results are achieved with the neutron diffraction patterns. The approach of predetermining the individual POF values from quantitative texture information can be used to improve refinement of other parameters related to the analysis of composite phases as well as to crystal structure refinement.

A Computer-Controlled X-Ray Diffractometer for Texture Studies of Polycrystalline Materials

1968 ◽  
Vol 12 ◽  
pp. 404-417 ◽  
Author(s):  
C. Richard Desper
Keyword(s):  
Computer Control ◽  
Orientation Distribution ◽  
Small Time ◽  
Polycrystalline Materials ◽  
Time Sharing ◽  
X Ray ◽  
Pole Figures ◽  
Continuous Scanning ◽  
Legendre Expansion

AbstractThe Picker Four-Angle Computer System (FACS-1), a computercontrolled x-ray diffractometer originally designed for single crystal studies, has been adapted for use with polycrystalline samples. The system is controlled by a PDP-8S, a small time-sharing computer with teletype input and output. Programs have been written to take advantage of the high degree of flexibility inherent in online computer control. Four basic operations are possible: (a) simple 2θ step-scanning with variable step width; (b) 2θ stepscanning with randomization of orientation; (c) determination of Legendre expansion coefficients for oriented specimens; and (d) determination of pole figures. In operation (a), data is gathered at a series of 2θ values at a prefixed count and/or time. In (b), the sample is rotated to average out orientation, giving the “randomized” intensity (2θ) at various 2θ values. The on-line computer reads the scaler and timer every two degrees of x rotation and forms the appropriate integrals for calculating (2θ) as the sample rotates. Operation (c) is an extension of (b): not only is (2θ) determined, but also various moments of the orientation distribution of the form , where Pn is the nth order Legendre polynomial. Operation (d) may be used to measure pole figures of sheet specimens in reflection or transmission, or of fibers or small particles. Optional modes of operation allow for (a) use of the Ross “balanced filter” technique; (b) integration across diffraction peaks by continuous scanning in 2θ, with background correction; and (c) application of absorption corrections.

The Influence of Errors of X-Ray Texture Measurements on ODF Calculation with Central Normal Distribution Approximation

2005 ◽  
Vol 495-497 ◽  
pp. 273-276
Author(s):  
T.M. Ivanova ◽  
H.U. Lubman ◽  
T.I. Savyolova ◽  
Vladimir Serebryany
Keyword(s):  
Normal Distribution ◽  
Measurement Errors ◽  
Orientation Distribution ◽  
Pole Density ◽  
Hexagonal Symmetry ◽  
Ray Method ◽  
Texture Measurement ◽  
Crystal Direction ◽  
X Ray ◽  
Pole Figures

Experimental pole figures are measured by x-ray method for materials with hexagonal symmetry (Ti and Mg alloys). The Orientation Distribution Function is calculated by approximation method with central normal distribution. Texture inhomogeneities and effects of defocusing are the main sources of pole density errors. The measurement errors depend on crystal direction {hkl} and are different for maximum and minimum regions on pole figure. The influence of texture measurement errors on accuracy of the ODF calculation is investigated.

Quantitative Texture Analysis from X-ray Diffraction Spectra

1997 ◽  
Vol 30 (4) ◽  
pp. 443-448 ◽  
Author(s):  
Y. D. Wang ◽  
L. Zuo ◽  
Z. D. Liang ◽  
C. Laruelle ◽  
A. Vadon ◽  
...  
Keyword(s):  
Distribution Function ◽  
Texture Analysis ◽  
Orientation Distribution Function ◽  
Diffraction Data ◽  
Polycrystalline Material ◽  
Orientation Distribution ◽  
New Method ◽  
X Ray Diffraction ◽  
X Ray

A method to obtain the orientation distribution function (ODF) of a polycrystalline material directly from X-ray diffraction spectra is presented. It uses the maximum-texture-entropy assumption to reduce the diffraction data needed for the ODF analysis. The validity of this new method is illustrated through two model examples.

Three-Dimensional X-Ray Diffraction Microscopy Using High-Energy X-Rays

MRS Bulletin ◽  
2004 ◽  
Vol 29 (3) ◽  
pp. 166-169 ◽  
Author(s):  
Henning F. Poulsen ◽  
Dorte Juul Jensen ◽  
Gavin B.M. Vaughan
Keyword(s):  
Materials Science ◽  
Three Dimensional ◽  
High Energy ◽  
Polycrystalline Materials ◽  
X Rays ◽  
X Ray Diffraction ◽  
X Ray ◽  
Reconstruction Methods ◽  
The Individual ◽  
Individual Grains

AbstractThree-dimensional x-ray diffraction (3DXRD) microscopy is a tool for fast and nondestructive characterization of the individual grains, subgrains, and domains inside bulk materials. The method is based on diffraction with very penetrating hard x-rays (E ≥ 50 keV), enabling 3D studies of millimeter-to-centimeter-thick specimens.The position, volume, orientation, and elastic and plastic strain can be derived for hundreds of grains simultaneously. Furthermore, by applying novel reconstruction methods, 3D maps of the grain boundaries can be generated. The 3DXRD microscope in use at the European Synchrotron Radiation Facility in Grenoble, France, has a spatial resolution of ∼5 μm and can detect grains as small as 150 nm. The technique enables, for the first time, dynamic studies of the individual grains within polycrystalline materials. In this article, some fundamental materials science applications of 3DXRD are reviewed: studies of nucleation and growth kinetics during recrystallization, recovery, and phase transformations, as well as studies of polycrystal deformation.

Onio-assistierte SN2-Reaktionen: Allgemeiner Zugang zu symmetrischen und unsymmetrischen geminal bisoniosubstituierten Methanderivaten / Onio-Assisted SN2-Reactions: General Access to Symmetrical and Unsymmetrical Geminally Bisonio Substituted Methane Derivatives

1998 ◽  
Vol 53 (5-6) ◽  
pp. 599-619 ◽  
Author(s):  
Robert Weiss ◽  
Matthias Handke ◽  
Silvia Reichel ◽  
Frank Hampel
Keyword(s):  
Transition State ◽  
Model Calculations ◽  
X Ray ◽  
Nucleophilic Carbenes ◽  
Sn2 Reactions ◽  
Condi Tions ◽  
Special Cases ◽  
Wide Range ◽  
The Stability

Abstract The arsonium salt [Ph3As-CH2-OTf]+ OTf- 11a contains a 1,1-biselectrophilic Csp3 center which permits to synthesize a wide range of symmetrical and unsymmetrical geminally bisonio-substituted methane derivatives. With neutral nucleophiles INu under mild condi- tions a series of 1.1-bisonium salts [Ph3As-CH2-Nu]2+ 2OTf- 12-23 is obtained in good yields. Under more stringent conditions the triphenylarsonio function in these salts can also be mobilized as a nucleofuge in a subsequent SN-reaction with a second nucleophile | Nu’, yielding a series of novel unsymmetrical 1,1-bisonium salts [Nu-CH2-Nu’]2+ 2OTf- 24-27. Structures 18, 23 and 26b were confirmed by X-ray analysis. For certain nucleophiles a discrete stepwise substitution of both nucleofuges in 11a cannot be realized and the corresponding symmetrical 1,1-bisonium salts (e.g. 28 and 30-32) are obtained directly. The experimental material can be rationalized on the basis of a simple MO model. The conclusion is that stabilization of a hypervalent SN2 transition state by an equatorial oniosubstituent parallels the stability of the underlying ylids. This is corroborated by model calculations. The geminal bisonium salts reported are potential precursors to mono- and 1,1-bisylids and, in special cases, to functional nucleophilic carbenes.

Automated Indexing of Laue Images from Polycrystalline Materials

1998 ◽  
Vol 524 ◽  
Author(s):  
Jin-Seok Chung ◽  
Gene E. Ice
Keyword(s):  
Polycrystalline Material ◽  
Polycrystalline Materials ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Conventional Analysis ◽  
Indexing Method ◽  
Wide Range ◽  
Single Grain ◽  
Individual Grains

ABSTRACTThird generation hard x-ray synchrotron sources and new x-ray optics have revolutionized x-ray microbeams. Now intense sub-micron x-ray beams are routinely available for x-ray diffraction measurement. An important application of sub-micron xray beams is analyzing polycrystalline material by measuring the diffraction of individual grains. For these measurements, conventional analysis methods will not work. The most suitable method for microdiffraction on polycrystalline samples is taking broad-bandpass or white-beam Laue images. With this method, the crystal orientation and non-isostatic strain can be measured rapidly without rotation of sample or detector. The essential step is indexing the reflections from more than one grain. An algorithm has recently been developed to index broad bandpass Laue images from multi-grain samples. For a single grain, a unique set of indices is found by comparing measured angles between Laue reflections and angles between possible indices derived from the x-ray energy bandpass and the scattering angle 2 theta. This method has been extended to multigrain diffraction by successively indexing points not recognized in preceding indexing iterations. This automated indexing method can be used in a wide range of applications.

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