scholarly journals Study of the texture and deformation mechanisms of MA2-1pch magnesium alloy upon rotary swaging

2018 ◽  
Vol 84 (8) ◽  
pp. 25-31
Author(s):  
V. N. Serebryany ◽  
I. A. Malyshev ◽  
D. N. Caikler ◽  
N. S. Martynenko ◽  
M. M. Morozov ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Magnesium Alloy ◽  
Basal Slip ◽  
Orientation Distribution ◽  
Deformation Mechanisms ◽  
Texture Formation ◽  
Initial State ◽  
X Ray ◽  
Rotary Swaging ◽  
Pole Figures

The use of quantitative X-ray texture analysis (QXRTA) (construction of the orientation distribution function (ODF) proceeding from the measurement of direct pole figures) and simulation of the texture formation in the framework of thermoactivation model (TA) are considered to study the features of texture formation in MA2-1pch magnesium alloy subjected to rotary swaging (RS) at 400 – 350°C. A diffuse texture consisting of basic and inclined to the pressing direction basic poles is formed in the alloy when temperature decreases and the total true deformations increase up to ε = 2.77. Model textures match experimental textures rather well when RS is provided by the action of basic ({0001} á1120), prismatic ({1010} á1120ñ) slip and twinning by the systems {1012} á1011ñ, {1011} á1012ñ, {1121} á1126ñ. Mathematical modeling of the textures also shows that the activity of the twinning systems under consideration increases in the sequence {1012} á1011ñ, {1011} á1012ñ, {1121} á1126ñ as the total deformations grow and RS temperature decreases. Those results are consistent with the previously obtained microstructural data. However, the differences in the orientation factors calculated for the initial state of the alloy and state after RS indicated to the activation of the basal slip and twinning systems under consideration, as well as to the difficulty of prismatic sliding. The obtained data are also consistent with the results of mathematical modeling of textures. At a temperature of 350°C at a total true deformation of 2.77 the basic deformation mechanisms (the basic slip and twinning by the systems {1012} á1011ñ, {1011} á1012ñ, {1121} á1126ñ) which ensure texture changes upon RS stimulate an enhance in the mechanical properties of magnesium alloy MA2-1pch bars.

Regular Substructure Inhomogeneity of Textured Materials by the Example of Rolled Ti-Ni Single Crystals

2005 ◽  
Vol 105 ◽  
pp. 207-212
Author(s):  
Yuriy Perlovich ◽  
Margarita Isaenkova ◽  
Vladimir Fesenko ◽  
Hans Joachim Bunge
Keyword(s):  
Plastic Deformation ◽  
Single Crystals ◽  
Residual Deformation ◽  
Deformation Mechanisms ◽  
Crystalline Lattice ◽  
Texture Formation ◽  
Ray Method ◽  
X Ray ◽  
Pole Figures ◽  
Textured Materials

The substructure inhomogeneity of rolled Ti-48%Ni-2%Fe single crystals was studied by the X-ray method of Generalized Pole Figures. Under rolling of single crystals, along with texture formation, the nonuniform substructure develops. It is conditioned by inhomogeneous reorientation of the crystalline lattice and local differences in predominant plastic deformation mechanisms. The distribution of residual deformation effects is controlled by the orientation of separate regions relative to texture maxima. Rolled single crystals prove to be divided into subcomponents with close orientations and opposite signs of elastic microstrains.

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.

Texture Development in a Model Al-Li Alloy Subjected to Severe Plastic Deformation

2006 ◽  
Vol 114 ◽  
pp. 337-344 ◽  
Author(s):  
Bogusława Adamczyk-Cieślak ◽  
Jaroslaw Mizera ◽  
Krzysztof Jan Kurzydlowski
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Equal Channel Angular Extrusion ◽  
Orientation Distribution ◽  
X Ray Diffraction ◽  
Technological Parameters ◽  
Initial State ◽  
Texture Characteristic ◽  
X Ray ◽  
Ultrafine Grained

The texture of Al – 0.7 wt. % Li alloy processed by two different methods of severe plastic deformation (SPD) has been investigated by X-ray diffraction, and analyzed in terms of the orientation distribution function (ODF). It was found that severe plastic deformation by both Equal Channel Angular extrusion (ECAE) and Hydrostatic Extrusion (HE) resulted in an ultrafine grained structure in an Al – 0.7 wt. % Li alloy. The microstructure, grain shape and size, of materials produced by SPD strongly depend on the technological parameters and methods applied. The texture of the investigated alloy differed because of the different modes of deformation. In the initial state the alloy exhibited a very strong texture consisting of {111} fibre component. A similar fibrous texture characteristic was also found after HE whereas after the ECAE the initial texture was completely changed.

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.

Quantitative X-Ray Analysis of Deformation Microtexture within Individual Grains

2005 ◽  
Vol 495-497 ◽  
pp. 983-988
Author(s):  
N.Yu. Ermakova ◽  
Nikolay Y. Zolotorevsky ◽  
Yuri Titovets
Keyword(s):  
Distribution Function ◽  
Uniaxial Compression ◽  
Orientation Distribution Function ◽  
Orientation Distribution ◽  
X Ray ◽  
Pole Figures ◽  
Single Grain ◽  
Individual Grains

The method is described which enables to determine the microtexture that is the orientation distribution within individual grains of a polycrystal. The microtexture is evaluated on the base of X-ray pole distributions measured for separate reflections, referred to as microscopic pole figures (MPF). The procedure for treatment of experimental MPF and the following computation of orientation distribution function is described in detail. Precision of the microtexture evaluation and possible ways of its improvement are discussed. As an example of the method application, orientation distribution within a single grain of aluminum polycrystal deformed by uniaxial compression up to 50% has been examined.

scholarly journals Microtexture Characterization by EBSP in Iron and Titanium Alloys

1993 ◽  
Vol 20 (1-4) ◽  
pp. 165-177 ◽  
Author(s):  
R. Penelle ◽  
T. Baudin
Keyword(s):  
Titanium Alloy ◽  
Distribution Function ◽  
Good Accuracy ◽  
Orientation Distribution ◽  
Orientation Measurement ◽  
X Ray ◽  
Pole Figures ◽  
Main Components ◽  
The Individual ◽  
The Right

The Orientation Distribution Function (O.D.F.) calculation is usually performed using pole figures measured by X-ray or neutron diffraction. However, this kind of experimental technique does not allow to determine a total ODF since the odd terms of the series expansion are not directly accessible from pole figures. The individual orientation measurement technique can be used but it is necessary to estimate the right orientation number necessary to calculate a statistically reliable ODF. For samples at the surface, at the fifth of the thickness from the surface and at the centre of a Fe 3% Si sheet, the present study shows that only 100 orientations are sufficient to find the main components of the texture but this number must be increased by a factor 10 to evaluate with a rather good accuracy the height of the peaks. In the case of a titanium alloy so called TA6V 350 orientations appear to be sufficient.

Influence of the Loading Path on the Deformation Mechanisms of Magnesium Alloys

2016 ◽  
Vol 258 ◽  
pp. 427-431
Author(s):  
Kristián Máthis ◽  
Jan Čapek ◽  
Bjørn Clausen ◽  
Tobias Panzner
Keyword(s):  
Acoustic Emission ◽  
Magnesium Alloy ◽  
Neutron Diffraction ◽  
Magnesium Alloys ◽  
Basal Slip ◽  
Mechanical Tests ◽  
Deformation Mechanisms ◽  
Loading Path ◽  
Dislocation Slip ◽  
Loading Direction

The evolution of deformation mechanisms in randomly textured magnesium alloy during uniaxial and biaxial mechanical tests has been monitored using concurrent application of acoustic emission and neutron diffraction methods. The influence of the loading path on both twinning and dislocation slip is discussed in detail. It is shown that both the twinning and non-basal slip are sensitive to the loading direction.

Polycrystal elastic constants for triclinic crystal and physical symmetry

2006 ◽  
Vol 39 (4) ◽  
pp. 502-508 ◽  
Author(s):  
Peter R. Morris
Keyword(s):  
Distribution Function ◽  
Orientation Distribution Function ◽  
Orientation Distribution ◽  
Weight Functions ◽  
Higher Symmetry ◽  
X Ray ◽  
Pole Figures ◽  
Generalized Spherical Harmonics ◽  
Physical Symmetry ◽  
Symmetry Operations

The problem of obtaining the Voigt average for the elastic stiffnesses with texture-describing weight functions has been solved for triclinic crystal and physical symmetries. The average is obtained by expanding theTijklmnpq, which relate the elastic stiffnesses in the rotated reference frame, c^{\,\prime}_{ijkl}, to those of the principal elastic stiffnesses,cmnpq, in generalized spherical harmonics, multiplying by the orientation distribution function and integrating over all orientations. The condition imposed to assure a unique expansion results in the absence of terms with oddL, so that the results are completely determinable from conventional X-ray pole figures. This is the most general case, from which all higher-symmetry solutions may be obtained by application of symmetry operations. The Reuss average for elastic compliances may be obtained in a similar fashion.

Features of Texture and Structure Development in Zirconium under Equal Channel Angular Pressing

2006 ◽  
Vol 503-504 ◽  
pp. 859-864 ◽  
Author(s):  
Yuriy Perlovich ◽  
Margarita Isaenkova ◽  
Vladimir Fesenko ◽  
M. Grekhov ◽  
Seng Ho Yu ◽  
...  
Keyword(s):  
Deformation Mechanisms ◽  
Line Profiles ◽  
Structure Development ◽  
Formation Theory ◽  
Ray Method ◽  
Texture Measurement ◽  
X Ray ◽  
Angular Pressing ◽  
Structure Changes ◽  
Pole Figures

A detailed X-ray study of Zr rods, subjected to ECAP at 350oC by routes C and BC, was conducted by the new X-ray method of Generalized Pole Figures, combining texture measurement with registration of X-ray line profiles. The data analysis is based on conceptions of the texture formation theory, connecting features of grain reorientation with activated deformation mechanisms. A degree of reproduction of the same distinctive texture by successive ECAP passes with antecedent rotation of the rod reflects attendant structure changes in material.

Advances in Texture Analysis from Diffraction Spectra

1997 ◽  
Vol 30 (1) ◽  
pp. 31-42 ◽  
Author(s):  
S. Matthies ◽  
L. Lutteroti ◽  
H. R. Wenk
Keyword(s):  
Neutron Diffraction ◽  
Structure Refinement ◽  
Orientation Distribution ◽  
Diffraction Spectrum ◽  
X Ray ◽  
Pole Figures ◽  
Overlapping Peaks ◽  
Lattice Planes ◽  
Synthetic Calcite ◽  
Low Symmetry

The orientation distribution of a textured polycrystal has been traditionally determined from a few individual pole figures of lattice planes hkl, measured by X-ray or neutron diffraction. A new method is demonstrated that uses the whole diffraction spectrum, rather than extracted peak intensities, by combining ODF calculation with Rietveld crystal structure refinement. With this method, which is illustrated for a synthetic calcite texture, it is possible to obtain quantitative texture information from highly incomplete pole figures and regions of the diffraction spectrum with many overlapping peaks. The approach promises to be advantageous for low-symmetry compounds and composites with complicated diffraction spectra. The method is particularly elegant for time-of-flight neutron diffraction, saving beam time by using small pole-figure regions and many diffractions.

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