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.

Determination of the wurtzite content and orientation distribution of nanowire ensembles

2009 ◽  
Vol 1206 ◽  
Author(s):  
Dominik Kriegner ◽  
Mario Keplinger ◽  
Julian Stangl ◽  
Aaron M. Andrews ◽  
Pavel Klang ◽  
...  
Keyword(s):  
Lattice Constant ◽  
Orientation Distribution ◽  
Growth Direction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pole Figures

AbstractWe present x-ray diffraction based methods to quantitatively determine the wurtzite content of nanowire ensembles and to investigate the effect of twinning. An increased lattice constant in growth direction is found for all investigated InAs and InP nanowire samples. This increase is independent of the wurtzite content. Using x-ray pole figures we find that twinning is present in GaAs/Si branched nanowires, which leads to 60° rotations of the lattice.

X-Ray Diffraction for Nondestructive Characterization of Polycrystalline Materials

1988 ◽  
Vol 142 ◽  
Author(s):  
C. O. Ruud ◽  
S. D. Weedman
Keyword(s):  
Computer Control ◽  
Polycrystalline Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Position Sensitive ◽  
Computer Controlled ◽  
Xrd Techniques ◽  
Nondestructive Characterization

AbstractX-ray diffraction has long been the mainstay for materials characterization in the laboratory. This characterization includes the determination of phase composition, residual stress, microstrain, grain size, and crystallographic texture of polycrystalline metals, ceramics, and minerals. The analytical capabilities of XRD techniques have been expanded recently by the application of computer control to data collection and processing. These capabilities include the identification of irregularities in metals and ceramics that are caused by processing and fatigue damage, as well as the apriori prediction of processing anomolies. While the above applications have been largely restricted to the laboratory, the possibility for exploitation of the nondestructive nature of x-ray diffraction for inprocess evaluation of materials is now being realized. The availability of computer-controlled position-sensitive x-ray detectors can now provide rapid, non-contacting, in-process interrogation of materials. The examples of nondestructive characterization illustrated in this paper will be those that can be used for process control and/or damage assessment.

X-Ray Diffraction Investigation of Electrochemically Deposited Copper

2004 ◽  
Vol 443-444 ◽  
pp. 201-204 ◽  
Author(s):  
Karen Pantleon ◽  
Jens Dahl Jensen ◽  
Marcel A.J. Somers
Keyword(s):  
Process Parameters ◽  
Orientation Distribution ◽  
Distribution Functions ◽  
Organic Additives ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pole Figures ◽  
Electrochemically Deposited ◽  
Cu Interconnect

Copper layers were deposited from acidic electrolytes containing different amounts of organic additives, designed for the formation of Cu-interconnect structures. Amorphous Ni-P substrates allow to study the unbiased growth of the electrodeposits. The crystallographic texture was investigated by the determination of X-ray diffraction (XRD) pole figures and the calculation of the orientation distribution functions. XRD results are discussed in relation to the morphologies of the electrodeposits as investigated with light optical microscopy and correlated with the process parameters during electrodeposition.

Textures Applied to Mechanical Processing Technology Assessment in Ancient Bronze

2005 ◽  
Vol 495-497 ◽  
pp. 719-724
Author(s):  
R.E. Bolmaro ◽  
B. Molinas ◽  
E. Sentimenti ◽  
A.L. Fourty
Keyword(s):  
Orientation Distribution ◽  
Distribution Functions ◽  
Archaeological Sites ◽  
Mechanical Processing ◽  
Post Processing ◽  
X Ray Diffraction ◽  
Mechanical Process ◽  
X Ray ◽  
Pole Figures ◽  
Microscopic Inspection

Some ancient metallic art craft, utensils, silverware and weapons are externally undistinguishable from modern ones. Not only the general aspect and shape but also some uses have not changed through the ages. Moreover, when just some small pieces can be recovered from archaeological sites, the samples can not easily be ascribed to any known use and consequently identified. It is clear that mechanical processing has changed along history but frequently only a "microscopic" inspection can distinguish among different techniques. Some bronze samples have been collected from the Quarto d’Altino (Veneto) archaeological area in Italy (paleovenetian culture) and some model samples have been prepared by a modern artisan. The sample textures have been measured by X-ray Diffraction techniques. (111), (200) and (220) pole figures were used to calculate Orientation Distribution Functions and further recalculate pole figures and inverse pole figures. The results were compared with modern forging technology results. Textures are able to discern between hammering ancient techniques for sheet production and modern industrial rolling procedures. However, as it is demonstrated in the present work, forgery becomes difficult to detect if the goldsmith, properly warned, proceeds to erase the texture history with some hammering post-processing. The results of this contribution can offer to the archaeologists the opportunity to take into consideration the texture techniques in order to discuss the origin (culture) of the pieces and the characteristic mechanical process developed by the ancient artisan. Texture can also help the experts when discussing the originality of a certain piece keeping however in mind the cautions indicated in this publication.

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.

A Method for Obtaining a Quantitative Pole Figure of Stretched Rubber

1957 ◽  
Vol 1 ◽  
pp. 131-142
Author(s):  
Otto Renius
Keyword(s):  
Pole Figure ◽  
Alpha Angle ◽  
Geiger Counter ◽  
Rubber Latex ◽  
X Ray ◽  
Outer Portion ◽  
Transmission Technique ◽  
Pole Figures ◽  
Orientation Pattern

AbstractWork at the Detroit Arsenal has shown that techniques similar to those employed for the determination of pole figures of metals can be utilized for studying organic materials such a a stretched rubber latex. The rubber, when stretched, forms a preferred orientation pattern which is proportional in intensity to the degree of elongation, and which can be used to plot a pole figure.A Geiger-counter spectrometer was used to study samples of rubber stretched 600 to 1000 per cent. Using a transmission technique, the specimens were tilted to the impinging X-ray beam in five degree increments while rotating through 360 degrees to allow the measurement of the diffracted beam from the selected atomic planes at various angles within the specimen. The intensities of the diffracted beam at these angles were plotted on a stereographic net to form the pole figures of the (002) and (012) planes of the stretched rubber. The geometry of the sample arrangements permitted the outer portion of the pole figure to be plotted from alpha angle 0 degrees to alpha angle 45 degrees.

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.

Distribution of Dislocation Density in Tubes from Zr-Based Alloys by X-Ray Data

2005 ◽  
Vol 105 ◽  
pp. 89-94 ◽  
Author(s):  
Margarita Isaenkova ◽  
Yuriy Perlovich
Keyword(s):  
Dislocation Density ◽  
Domain Size ◽  
Ray Method ◽  
Coherent Domain Size ◽  
Texture Measurement ◽  
Burgers Vector ◽  
X Ray ◽  
Pole Figures ◽  
Coherent Domain

As applied to tubes from Zr-based alloys, the X-ray method was developed to determine the dislocation density distribution in a-Zr depending on the orientation of Burgers vector. The method consists in registration of X-ray line profiles by each successive position of the sample in the course of diffractometric texture measurement using reflections of two orders, the following determination of coherent domain size and lattice distortion by means of the Warren-Averbach method for each orientation of reflecting planes, separate calculation of the density of c- and a-dislocations with all possible orientations of Burgers vector and presentation of results in generalized pole figures. Obtained data testify that the dislocation density varies within very wide intervals of several orders of magnitude depending on the grain orientation both in as-rolled and annealed tubes. Features of the constructed dislocation distributions are closely related to the crystallographic texture of studied tubes.

scholarly journals An Investigation Into the Accuracy of the Vector Method by Comparison With ECP Measurements

1989 ◽  
Vol 10 (2) ◽  
pp. 117-134 ◽  
Author(s):  
R. Shimizu ◽  
J. Harase ◽  
K. Ohta
Keyword(s):  
Pole Figure ◽  
Direct Measurement ◽  
Orientation Distribution ◽  
Vector Method ◽  
Inversion Result ◽  
X Ray ◽  
Pole Figures ◽  
The Mean ◽  
Actual Orientation ◽  
Good Agreement

In an attempt to investigate the accuracy of the vector method for crystal texture analysis, a comparison has been made between the inversion result of the pole figure made by X-ray studies using the VM and the inversion result of the pole figure made by ECP. A comparison has been made between the inversion by the pole figure generated by direct measurement of orientations by ECP and the actual orientation distribution (measured by ECP) displayed in the same mode. The materials studied were recrystallized Fe–3% Si and Fe–50% Ni. The main findings were:• In the mean intensities of each individual Box, the inversion results of pole figures made from orientations determined by ECP were in good agreement with the inversion from (100) pole figures made by X-ray or actual orientation distribution (made by ECP) displayed in the same mode as the vector method.• For Fe–3% Si, quite a good agreement was obtained between the results inverted from X-ray pole figure and the direct measurement by ECP for the intensity distribution of minor texture component along ζ angle. It was concluded from these investigations that the inversion of the pole figure by the vector method is accurate enough for most practical purposes.

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