Simultaneous Spiral Recording of Pole Figures on Polaroid Film for Texture Goniometers

1972 ◽  
pp. 499-503
Author(s):  
H. Ebel ◽  
M. F. Ebel
Keyword(s):  
Pole Figures

Use of generalised pole figures in the X-ray study of textured metal materials

2007 ◽  
Vol 2007 (suppl_26) ◽  
pp. 327-332
Author(s):  
Yu. Perlovich ◽  
M. Isaenkova ◽  
V. Fesenko
Keyword(s):  
X Ray ◽  
Pole Figures ◽  
Metal Materials

MISORIENTATION DISTRIBUTION FUNCTION FOR CUBIC CRYSTALS

2019 ◽  
Vol 85 (5) ◽  
pp. 28-32
Author(s):  
A. S. Kolyanova ◽  
Y. N. Yaltsev
Keyword(s):  
Distribution Function ◽  
Grain Boundaries ◽  
Orientation Distribution ◽  
Recrystallization Annealing ◽  
Misorientation Distribution ◽  
Cubic Crystals ◽  
Special Boundaries ◽  
Pole Figures ◽  
Two Samples ◽  
Euler Space

A calculation method for obtaining the misorientation distribution function (MDF) for cubic crystals which can be used to estimate the presence or absence of special boundaries in the materials is presented. The calculation was carried out for two samples of Al-Mg-Si alloy subjected to various mechanical and thermal treatments: the first sample is subjected to rolling; the second sample is subjected to recrystallization annealing. MDF is calculated for each sample; the results are presented in the Euler space and in the angle-axis space. The novelty of the method consists in the possibility of gaining data on the grain boundaries from X-ray texture analysis without using electron microscopy. A calculation involving only mathematical operations on matrices was performed on the basis of the orientation distribution function restored from incomplete pole figures. It is shown that no special boundaries are observed in the deformed sample, whereas in the recrystallized alloy, special boundaries are detected at Ʃ = 23, 13, and 17. The shortcoming of the proposed method can be attributed to the lack of accurate data on grain boundaries, since all possible orientation in the polycrystal should be taken into account in MDF calculation.

scholarly journals Study on a New Forming Method—Thread Rolling by Crystal Plasticity Finite Element Simulation

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 503
Author(s):  
Yuheng Zhang ◽  
Zhiqing Hu ◽  
Liming Guo
Keyword(s):  
Finite Element ◽  
Crystal Plasticity ◽  
Strain Curve ◽  
Forming Process ◽  
Crystal Plasticity Finite Element ◽  
Pole Figures ◽  
Grain Orientations ◽  
Thread Rolling ◽  
Polycrystalline Model ◽  
High Consistency

In order to study a new thread rolling forming process from a microscopic perspective, a polycrystalline model was established, based on the crystal plasticity finite element method (CPFEM) and Voronoi polyhedron theory. The fluidity of metals was studied to explain the reason for the concave center. The simulation results show that the strain curve of the representative element can more truly reflect the deformation behavior of the material. The grain orientations after deformation are distributed near the initial orientation. The evolution of each slip system is determined by the initial grain orientations and grain locations. The pole figures obtained from the experiment show high consistency with the pole figures obtained by simulation, which verifies the accuracy of the texture prediction by CPFEM. The experimental results show that thread rolling is more uniform in deformation than ordinary rolling.

scholarly journals Symmetry Breakdown Related Fracture in 42CrMo4 Steel

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 344
Author(s):  
Jian Feng ◽  
Stefan Barth ◽  
Marc Wettlaufer
Keyword(s):  
Orientation Distribution ◽  
High Symmetry ◽  
Symmetry Breakdown ◽  
Pole Figures ◽  
Crystallographic Symmetry ◽  
42Crmo4 Steel ◽  
Austenite Grains ◽  
Ebsd Technique ◽  
Complete Transformation ◽  
Start Temperature

Austenite grains that underwent the f.c.c. to b.c.c. (or b.c.t.) transformation are typically composed of 24 Kurdjumov–Sachs variants that can be categorized by three axes of Bain transformations; thus, a complete transformation generally displays 3-fold symmetry in (001) pole figures. In the present work, crystallographic symmetry in 42CrMo4 steel austempered below martensite start temperature was investigated with the help of the orientation distribution function (ODF) analysis based on the FEG-SEM/EBSD technique. It is shown that, upon phase transformations, the specimens contained 6-fold symmetry in all (001), (011), and (111) pole figures of an ODF. The ODF analysis, verified by theoretical modeling, showed that under plane-strain conditions cracks prefer to propagate through areas strongly offset by the high symmetry. The origin of high symmetry was investigated, and the mechanism of the symmetry breakdown was explained.

scholarly journals Correction of Pole Figures Measured on Small Diameter Metallic Wires

1991 ◽  
Vol 14 ◽  
pp. 175-180 ◽  
Author(s):  
M. Francois ◽  
J. M. Sprauel ◽  
J. L. Lebrun ◽  
G. Chalant
Keyword(s):  
Small Diameter ◽  
Pole Figures ◽  
Metallic Wires

Preparation and Electrical Characteristics of (100), (111), and Randomly Oriented PZT Thin Films

1994 ◽  
Vol 361 ◽  
Author(s):  
Chang Jung Kim ◽  
Dae Sung Yoon ◽  
Joon Sung Lee ◽  
Chaun Gi Choi ◽  
Won Jong Lee ◽  
...  
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Hysteresis Loops ◽  
Test System ◽  
Electrical Characteristics ◽  
Pzt Thin Films ◽  
Pole Figures ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
Drying Conditions

ABSTRACTThe (100), (111) and randomly oriented PZT thin films were fabricated on Pt/Ti/Coming 7059 glass using sol-gel method. The thin films having different orientation were fabricated by different drying conditions for pyrolysis. The preferred orientations of the PZT thin films were observed using XRD, rocking curves, and pole figures. The microstructures were investigated using SEM. The hysteresis loops and capacitance-voltage characteristics of the films were investigated using a standardized ferroelectric test system. The dielectric constant and current-voltage characteristics of the films were investigated using an impedance analyzer and pA meter, respectively. The films oriented in a particular direction showed superior electrical characteristics to the randomly oriented films.

Use of Neutron Diffraction for Describing Texture of Isostatically-Pressed Molybdite Powders

2005 ◽  
Vol 105 ◽  
pp. 83-88 ◽  
Author(s):  
H. Sitepu ◽  
Heinz Günter Brokmeier
Keyword(s):  
Crystal Structure ◽  
Neutron Diffraction ◽  
Powder Diffraction ◽  
Quantitative Description ◽  
Neutron Powder Diffraction ◽  
Powder Diffraction Data ◽  
Neutron Powder Diffraction Data ◽  
Pole Figures ◽  
Diffraction Patterns ◽  
Excellent Tool

The modelling and/or describing of texture (i.e. preferred crystallographic orientation (PO)) is of critical importance in powder diffraction analysis - for structural study and phase composition. In the present study, the GSAS Rietveld refinement with generalized spherical harmonic (GSH) was used for describing isostatically-pressed molybdite powders neutron powder diffraction data collected in the ILL D1A instrument. The results showed that for texture in a single ND data of molybdite the reasonable crystal structure parameters may be obtained when applying corrections to intensities using the GSH description. Furthermore, the WIMV method was used to extract the texture description directly from a simultaneous refinement with 1368 whole neutron diffraction patterns taken from the sample held in a variety of orientations in the ILL D1B texture goniometer. The results provided a quantitative description of the texture refined simultaneously with the crystal structure. Finally, the (002) molybdite pole-figures were measured using the GKSS TEX2 texture goniometer. The results showed that neutron diffraction is an excellent tool to investigate the texture in molybdite.

scholarly journals The Texture of a Slate From Nantlle, Caernarvon, North Wales

Texture ◽  
1972 ◽  
Vol 1 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Gerhard Oertel ◽  
Prem P. Phakey
Keyword(s):  
Ultrathin Section ◽  
Orthorhombic Symmetry ◽  
X Ray ◽  
Plane Normal ◽  
North Wales ◽  
Pole Figures ◽  
Sheet Silicate ◽  
Diffraction Patterns ◽  
Local Dissolution ◽  
Mechanical Rotation

A specimen of Cambrian slate from the slate belt in North Wales has been thinned by the ion bombardment technique to produce an ultrathin section with the specimen plane normal to the cleavage plane. This specimen has been investigated with the electron microscope by electron transmission. Selected area diffraction patterns allow identification of individual sheet silicate grains. The pole figures of the basal planes of two sheet silicate minerals, muscovite and chlorite, have been measured with an X-ray pole-figure goniometer and both show an elongated maximum normal to the slaty cleavage, with orthorhombic symmetry. While the preferred orientation could be the result of mechanical rotation of rigid flakes in a deforming matrix, the texture (the overall pattern due to the shapes and sizes of grains and their angular relations to each other) can only be explained if considerable recrystallization is assumed. It is tentatively proposed that local dissolution at points of stress-concentration with simultaneous redeposition of the dissolved material in less stressed regions may have allowed closely packed grains to act as if they were mechanically rotating rigid flakes, yet to accommodate their shapes enough to prevent interlocking.

scholarly journals Approximation of the Orientation Distribution of Grains in Polycrystalline Samples by Means of Gaussians

1992 ◽  
Vol 19 (1-2) ◽  
pp. 9-27 ◽  
Author(s):  
D. I. Nikolayev ◽  
T. I. Savyolova ◽  
K. Feldmann
Keyword(s):  
Rolling Texture ◽  
Expansion Method ◽  
Operating Mode ◽  
Orientation Distribution ◽  
New Method ◽  
Gaussian Distributions ◽  
Positivity Condition ◽  
The Central Limit Theorem ◽  
Pole Figures ◽  
Series Expansion Method

The orientation distribution function (ODF) obtained by classical spherical harmonics analysis may be falsified by ghost influences as well as series truncation effects. The ghosts are a consequence of the inversion symmetry of experimental pole figures which leads to the loss of information on the “odd” part of ODF.In the present paper a new method for ODF reproduction is proposed. It is based on the superposition of Gaussian distributions satisfying the central limit theorem in the SO(3)-space as well as the ODF positivity condition. The kind of ODF determination offered here is restricted to the fit of Gaussian parameters and weights with respect to the experimental pole figures. The operating mode of the new method is demonstrated for a rolling texture of copper. The results are compared with the corresponding ones obtained by the series expansion method.

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