Deconvolution of x-ray diffraction data to elucidate plastic deformation mechanisms in the uniaxial extension of bulk nylon 6

1991 ◽  
Vol 24 (13) ◽  
pp. 3945-3952 ◽  
Author(s):  
A. Galeski ◽  
A. S. Argon ◽  
R. E. Cohen
Keyword(s):  
Plastic Deformation ◽  
Diffraction Data ◽  
Uniaxial Extension ◽  
Nylon 6 ◽  
Deformation Mechanisms ◽  
X Ray Diffraction ◽  
X Ray

Microstructural Changes during Precision Machining of Thin Substrates

2010 ◽  
Vol 447-448 ◽  
pp. 76-80
Author(s):  
K. Saptaji ◽  
Subbiah Sathyan
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Crystallographic Orientation ◽  
High Ratio ◽  
Machining Process ◽  
Deformation Mechanisms ◽  
Precision Machining ◽  
Depth Of Cut ◽  
X Ray Diffraction ◽  
X Ray

This paper reports investigations in machining of thin substrates with thickness less than 100m. The machining process induces severe plastic deformation through the thickness of the machined thin workpiece due to the high ratio of the depth of cut to workpiece thickness. The diamond face turning is used to machine thin workpieces down to a thickness less than 100m. The microstructure of the machined sample is studied and x-ray diffraction used to observe the crystallographic orientation / texture. The microstructures of the thin machined workpieces are seen to become more random, denser, and finer with the shape of the grains less elongated as compare to the bulk and thick machined sample. The x-ray diffraction analyses indicate that machining of thin substrates changes the texture or orientation. Different deformation mechanisms may occur when machining thin workpiece especially at thicknesses below 100m.

scholarly journals Probing the Deformation Mechanisms of Nanocrystalline Silver by In-Situ Tension and Synchrotron X-ray Diffraction

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1635
Author(s):  
Baoru Sun ◽  
Tongde Shen
Keyword(s):  
Plastic Deformation ◽  
Grain Growth ◽  
Structural Parameters ◽  
Stacking Faults ◽  
Constant Strain Rate ◽  
Deformation Mechanisms ◽  
Square Root ◽  
X Ray Diffraction ◽  
X Ray ◽  
Density Of Dislocations

The mechanisms responsible for the deformation of nanocrystalline materials are not well understood although many mechanisms have been proposed. This article studies the room-temperature stress-strain relations of bulk nanocrystalline silver deformed in a tension mode at a constant strain rate. Synchrotron X-ray diffraction patterns were gathered from the deformed specimen and used to deduce such structural parameters as the grain size and the density of dislocations, twins, and stacking faults. Our quantitative results indicate that grain growth and twinning occur in the stage of elastic deformation. Detwinning and accumulation of stacking faults occur in the early stage of plastic deformation, where the strength of nanocrystalline silver correlates well with the square root of stacking faults probability. Grain shrinking and generation of statistically stored dislocations occur in the final stage of plastic deformation, where the strength of nanocrystalline silver correlates well with the square root of the density of dislocations (statistically stored and geometrically necessary). Our results suggest that multiple deformation mechanisms such as grain growth, grain shrinking, twinning, detwinning, stacking faults, and dislocations, rather than a single deformation mechanism, occur in the elastic and plastic deformation stages of nanocrystalline silver.

scholarly journals High-pressure synthesis and crystal structure of the mixed-cation borate Ga4In4B15O33(OH)3

2019 ◽  
Vol 74 (4) ◽  
pp. 357-363
Author(s):  
Daniela Vitzthum ◽  
Hubert Huppertz
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
High Temperature ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
Mixed Cation ◽  
High Pressure High Temperature ◽  
Pressure Synthesis

AbstractThe mixed cation triel borate Ga4In4B15O33(OH)3 was synthesized in a Walker-type multianvil apparatus at high-pressure/high-temperature conditions of 12.5 GPa and 1300°C. Although the product could not be reproduced in further experiments, its crystal structure could be reliably determined via single-crystal X-ray diffraction data. Ga4In4B15O33(OH)3 crystallizes in the tetragonal space group I41/a (origin choice 2) with the lattice parameters a = 11.382(2), c = 15.244(2) Å, and V = 1974.9(4) Å3. The structure of the quaternary triel borate consists of a complex network of BO4 tetrahedra, edge-sharing InO6 octahedra in dinuclear units, and very dense edge-sharing GaO6 octahedra in tetranuclear units.

Crystallization and preliminary x-ray diffraction data of the cryptomonad biliprotein phycocyanin-645 from a Chroomonas spec.

1984 ◽  
Vol 140 (2-3) ◽  
pp. 202-205 ◽  
Author(s):  
Walter Morisset ◽  
Werner Wehrmeyer ◽  
Tilman Schirmer ◽  
Wolfram Bode
Keyword(s):  
Diffraction Data ◽  
X Ray Diffraction ◽  
X Ray

Theoretically derived thermodynamic properties can be improved by the refinement of low-frequency modes against X-ray diffraction data

2021 ◽  
Author(s):  
Anna Agnieszka Hoser ◽  
Marcin Sztylko ◽  
Damian Trzybiński ◽  
Anders Østergaard Madsen
Keyword(s):  
Thermodynamic Properties ◽  
Dft Calculations ◽  
Diffraction Data ◽  
Molecular Crystals ◽  
Low Frequency ◽  
X Ray Diffraction ◽  
X Ray ◽  
Efficient Approach

A framework for estimation of thermodynamic properties for molecular crystals via refinement of frequencies from DFT calculations against X-ray diffraction data is presented. The framework provides an efficient approach to...

Single-crystal investigation of Ce5AgxGe4−x (x = 0.1−1.08) with Sm5Ge4 type

2020 ◽  
Vol 75 (8) ◽  
pp. 765-768
Author(s):  
Bohdana Belan ◽  
Dorota Kowalska ◽  
Mariya Dzevenko ◽  
Mykola Manyako ◽  
Roman Gladyshevskii
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Diffraction Data ◽  
Binary Compound ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray

AbstractThe crystal structure of the phase Ce5AgxGe4−x (x = 0.1−1.08) has been determined using single-crystal X-ray diffraction data for Ce5Ag0.1Ge3.9. This phase is isotypic with Sm5Ge4: space group Pnma (No. 62), Pearson code oP36, Z = 4, a = 7.9632(2), b = 15.2693(5), c = 8.0803(2) Å; R1 = 0.0261, wR2 = 0.0460, 1428 F2 values and 48 variables. The two crystallographic positions 8d and 4c show Ge/Ag mixing, leading to a slight increase in the lattice parameters as compared to those of the pure binary compound Ce5Ge4.

The modulated structure of Bi2Sr3−xCaxCu2O8: A commensurate model from single crystal X-ray diffraction data

1989 ◽  
Vol 161 (5-6) ◽  
pp. 598-606 ◽  
Author(s):  
G. Calestani ◽  
C. Rizzoli ◽  
M.G. Francesconi ◽  
G.D. Andreetti
Keyword(s):  
Single Crystal ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
Modulated Structure ◽  
X Ray

scholarly journals Crystallographic features of ammonium fluoroelpasolites: dynamic orientational disorder in crystals of (NH4)3HfF7 and (NH4)3Ti(O2)F5

2017 ◽  
Vol 73 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Anatoly A. Udovenko ◽  
Alexander A. Karabtsov ◽  
Natalia M. Laptash
Keyword(s):  
Single Crystal ◽  
Electron Density ◽  
Diffraction Data ◽  
Central Atom ◽  
X Ray Diffraction ◽  
Dynamic Nature ◽  
Orientational Disorder ◽  
High Quality ◽  
Structural Units ◽  
X Ray

A classical elpasolite-type structure is considered with respect to dynamically disordered ammonium fluoro-(oxofluoro-)metallates. Single-crystal X-ray diffraction data from high quality (NH4)3HfF7 and (NH4)3Ti(O2)F5 samples enabled the refinement of the ligand and cationic positions in the cubic Fm \bar 3 m (Z = 4) structure. Electron-density atomic profiles show that the ligand atoms are distributed in a mixed (split) position instead of 24e. One of the ammonium groups is disordered near 8c so that its central atom (N1) forms a tetrahedron with vertexes in 32f. However, a center of another group (N2) remains in the 4b site, whereas its H atoms (H2) occupy the 96k positions instead of 24e and, together with the H3 atom in the 32f position, they form eight spatial orientations of the ammonium group. It is a common feature of all ammonium fluoroelpasolites with orientational disorder of structural units of a dynamic nature.

The crystal structure of gypsum-II determined by single-crystal synchrotron X-ray diffraction data

2010 ◽  
Vol 95 (4) ◽  
pp. 655-658 ◽  
Author(s):  
S. Nazzareni ◽  
P. Comodi ◽  
L. Bindi ◽  
L. Dubrovinsky
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
X Ray
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