scholarly journals Generalization of the Concept of Sample Symmetry- Fuzzy Symmetry, Symmetroids, Similarity

1997 ◽  
Vol 29 (3-4) ◽  
pp. 127-154 ◽  
Author(s):  
Hans-Joachim Bunge ◽  
Ina Nielsen
Keyword(s):  
Crystal Orientation ◽  
Rolling Direction ◽  
Orientation Distribution ◽  
Coarse Grained ◽  
Polycrystalline Materials ◽  
Sheet Rolling ◽  
Practical Applications ◽  
Crystal Orientation Distribution Function ◽  
Internal Symmetries

The crystal orientation distribution function of polycrystalline materials, i.e. the texture, may exhibit internal symmetries due to symmetries of the production steps, or more generally, to the whole materials history. The “sharpness” of such symmetries can be quantified in terms of various symmetry parameters. If the symmetries of subsequent production processes are different, e.g. of sheet rolling and deep drawing, then these symmetries may still be recognized in the final texture. In the same way also similarities of textures and properties of different materials can be quantified. Symmetry parameters have many practical applications. Examples of that are the determination of rolling direction corrections, determination of the “plastic spin”, estimation of coarse-grained materials, or finding the “correct” (symmetry adapted) axis system in a material.

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.

The Effect of Cold Rolling Reduction on Shear Band and Texture Formation in Fe-3%Si Alloy

2012 ◽  
Vol 715-716 ◽  
pp. 158-163 ◽  
Author(s):  
Kenichi Murakami ◽  
N. Morishige ◽  
Kohsaku Ushioda
Keyword(s):  
Shear Band ◽  
Cold Rolling ◽  
Crystal Orientation ◽  
Shear Bands ◽  
Rolling Direction ◽  
Orientation Distribution ◽  
Rolling Reduction ◽  
Shear Band Formation ◽  
Band Formation ◽  
Cold Rolling Reduction

The effect of cold rolling reduction on shear band formation and crystal orientation within shear bands and annealing texture were investigated in Fe-3%Si {111}<112> single crystals. Several types of shear bands were observed with different angles to rolling direction, dependent on rolling reduction. As for shear band formation, those with smaller angles were formed earlier and those with larger angles were formed later. Regarding crystal orientation along shear bands after rolling reduction, orientation distribution from the initial became large in accordance with reduction and even exceeded Goss orientation when rolling reduction became larger than 40%. After annealing, however, recrystallized grains along shear bands were mainly Goss grains regardless of reduction. The speculated reason for the dominance of Goss after annealing is that Goss subgrains with less density of dislocations were surrounded by largely deformed areas.

Calculation of the crystal orientation distribution function from synchrotron radiation experimental data

1989 ◽  
Vol 22 (6) ◽  
pp. 559-561 ◽  
Author(s):  
J. A. Szpunar ◽  
P. Blandford ◽  
D. C. Hinz
Keyword(s):  
Experimental Data ◽  
Distribution Function ◽  
Synchrotron Radiation ◽  
Orientation Distribution Function ◽  
Crystal Orientation ◽  
Orientation Distribution ◽  
Pole Figures ◽  
Cold Rolled ◽  
Expansion Coefficients ◽  
Crystal Orientation Distribution Function

Series-expansion coefficients for an orientation distribution function (ODF) of cold-rolled aluminium sheet were calculated from the intensity of Debye–Scherrer rings obtained in an experiment using synchrotron radiation. Calculated and observed pole figures demonstrate that a sufficiently good approximation to the ODF is obtained from coefficients calculated to l = 8.

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.

Mapping the Crystal Orientation Distribution Function to Discrete Orientations in Crystal Plasticity Finite Element Forming Simulations of Bulk Materials

2006 ◽  
Vol 519-521 ◽  
pp. 803-808
Author(s):  
Franz Roters
Keyword(s):  
Finite Element ◽  
Distribution Function ◽  
Crystal Plasticity ◽  
Orientation Distribution Function ◽  
Crystal Orientation ◽  
Orientation Distribution ◽  
Bulk Materials ◽  
Crystal Plasticity Finite Element ◽  
Forming Simulations ◽  
Crystal Orientation Distribution Function

The crystal plasticity finite element method (CPFEM) is probably the method with the best potential to directly incorporate crystal anisotropy and its evolution into forming simulations. However, when it comes to the simulation of bulk materials, the representation of the crystal orientation distribution function (ODF), i.e. of the statistical texture, within the CPFEM framework becomes a key issue for the efficiency of the approach. In this work two different approaches for sampling the ODF are compared. The first is the so called Texture-Component-CPFEM, where the discretisation is based on the representation of the ODF by texture components. The second approach is based on the representation of the ODF by series expansion and uses a direct mapping of the ODF represented in the form of C-coefficients to individual orientations as needed by the CPFEM. Both methods are compared using the textures of Aluminum hot band as well as cold rolled material.

Approximation of pole figures for the determination of crystal orientation in polymeric solids

1990 ◽  
Vol 23 (2) ◽  
pp. 88-93 ◽  
Author(s):  
P. Sajkiewicz ◽  
A. Wasiak
Keyword(s):  
Crystal Orientation ◽  
Linear Optimization ◽  
Orientation Distribution ◽  
Important Application ◽  
X Rays ◽  
Distribution Characteristics ◽  
Optimization Program ◽  
Pole Figures ◽  
Oriented Polycrystalline

The approximation of experimentally measured angular intensity distributions of X-rays diffracted by oriented polycrystalline specimens is suggested as a method for the determination of orientation distribution characteristics for uniaxially oriented polymeric fibres. A non-linear optimization program based on a Hook–Jeeves algorithm is elaborated and incorporated into the method. As an example, the interpretation of the data from polyethylene specimens having various degrees of orientation is given. An important application of the method is the analysis of distributions (pole figures) using a superposition of two identical or similar functions with different parameters.

Influence of extinction phenomenon on determination of the orientation distribution function

2006 ◽  
Vol 2006 (suppl_23_2006) ◽  
pp. 175-180
Author(s):  
G. Gómez-Gasga ◽  
T. Kryshtab ◽  
J. Palacios-Gómez ◽  
A. de Ita de la Torre
Keyword(s):  
Distribution Function ◽  
Orientation Distribution Function ◽  
Orientation Distribution

scholarly journals Coupled Thermomechanical Response Measurement of Deformation of Nickel-Based Superalloys Using Full-Field Digital Image Correlation and Infrared Thermography

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2163
Author(s):  
Krzysztof Żaba ◽  
Tomasz Trzepieciński ◽  
Sandra Puchlerska ◽  
Piotr Noga ◽  
Maciej Balcerzak
Keyword(s):  
Surface Temperature ◽  
Strain Rate ◽  
Rolling Direction ◽  
Image Correlation ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Response Measurement ◽  
Sheet Rolling ◽  
Inconel Alloys ◽  
The Relationship

The paper is devoted to highlighting the potential application of the quantitative imaging technique through results associated with work hardening, strain rate and heat generated during elastic and plastic deformation. The aim of the research presented in this article is to determine the relationship between deformation in the uniaxial tensile test of samples made of 1-mm-thick nickel-based superalloys and their change in temperature during deformation. The relationship between yield stress and the Taylor–Quinney coefficient and their change with the strain rate were determined. The research material was 1-mm-thick sheets of three grades of Inconel alloys: 625 HX and 718. The Aramis (GOM GmbH, a company of the ZEISS Group) measurement system and high-sensitivity infrared thermal imaging camera were used for the tests. The uniaxial tensile tests were carried out at three different strain rates. A clear tendency to increase the sample temperature with an increase in the strain rate was observed. This conclusion applies to all materials and directions of sample cutting investigated with respect to the sheet-rolling direction. An almost linear correlation was found between the percent strain and the value of the maximum surface temperature of the specimens. The method used is helpful in assessing the extent of homogeneity of the strain and the material effort during its deformation based on the measurement of the surface temperature.

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