Dislocation Structure and Crystallite Size Distribution in Plastically Deformed Metals Determined by Diffraction Peak Profile Analysis

2001 ◽  
Vol 124 (1) ◽  
pp. 2-6 ◽  
Author(s):  
T. Unga´r ◽  
G. Riba´rik ◽  
J. Gubicza ◽  
P. Hana´k
Keyword(s):  
Crystallite Size ◽  
Fourier Transforms ◽  
Profile Analysis ◽  
Diffraction Peak ◽  
Size Distributions ◽  
X Ray Diffraction ◽  
Edge Type ◽  
X Ray ◽  
Dislocation Densities ◽  
Strong Dipole

The dislocation densities and arrangement parameters and the crystallite size and size-distributions are determined in tensile or cyclically deformed polycrystalline copper specimens by X-ray diffraction peak profile analysis. The Fourier coefficients of profiles measured by a special high resolution X-ray diffractometer with negligible instrumental broadening have been fitted by the Fourier transforms of ab-initio size and strain profiles. It is found that in the fatigued samples the dislocations are mainly of edge type with strong dipole character. In the fatigued specimens the dislocation densities are found to be larger than in the tensile deformed samples when the saturation and flow stress levels are the same.

Dislocation densities and crystallite size distributions in nanocrystalline ball-milled fluorides,MF2(M= Ca, Sr, Ba and Cd), determined by X-ray diffraction line-profile analysis

2005 ◽  
Vol 38 (6) ◽  
pp. 912-926 ◽  
Author(s):  
G. Ribárik ◽  
N. Audebrand ◽  
H. Palancher ◽  
T. Ungár ◽  
D. Louër
Keyword(s):  
Crystallite Size ◽  
Line Profile ◽  
Interference Effect ◽  
Profile Analysis ◽  
Line Profile Analysis ◽  
Size Distributions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Line Profile ◽  
Dislocation Densities

The dislocation densities and crystallite size distributions in ball-milled fluorides,MF2(M= Ca, Sr, Ba and Cd), of the fluorite structure type have been determined as a function of milling time by X-ray diffraction line-profile analysis. The treatment has been based on the concept of dislocation contrast to explain strain anisotropy by means of the modified Williamson–Hall and Warren–Averbach approaches and a whole-profile fitting method using physically based functions. In most cases, the measured and calculated patterns are in perfect agreement; however, in some specific cases, the first few measured profiles appear to be narrower than the calculated ones. This discrepancy is interpreted as the result of an interference effect similar to that described by Rafaja, Klemm, Schreiber, Knapp & Kužel [J. Appl. Cryst.(2004),37, 613–620]. By taking into account and correcting for this interference effect, the microstructure of ball-milled fluorides is determined in terms of dislocation structure and size distributions of coherent domains. A weak coalescence of the crystallites is observed at longer milling periods. An incubation period in the evolution of microstrains is in correlation with the homologous temperatures of the fluorides.

Crystallite size and lattice strain of lithiated spinel material for rechargeable battery by X-ray diffraction peak-broadening analysis

2019 ◽  
Vol 43 (5) ◽  
pp. 1903-1911 ◽  
Author(s):  
Ahmed A. Al-Tabbakh ◽  
Nilgun Karatepe ◽  
Aseel B. Al-Zubaidi ◽  
Aida Benchaabane ◽  
Natheer B. Mahmood
Keyword(s):  
Crystallite Size ◽  
Lattice Strain ◽  
Diffraction Peak ◽  
Rechargeable Battery ◽  
X Ray Diffraction ◽  
X Ray ◽  
Peak Broadening

X-ray diffraction Warren–Averbach mullite analysis in whiteware porcelains: influence of kaolin raw material

Clay Minerals ◽  
2018 ◽  
Vol 53 (3) ◽  
pp. 471-485 ◽  
Author(s):  
Angel Sanz ◽  
Joaquín Bastida ◽  
Angel Caballero ◽  
Marek Kojdecki
Keyword(s):  
Crystallite Size ◽  
Firing Temperature ◽  
Microstructural Analysis ◽  
Stoichiometric Composition ◽  
Raw Material ◽  
Size Distributions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures ◽  
Crystallite Sizes

ABSTRACTCompositional and microstructural analysis of mullites in porcelain whitewares obtained by the firing of two blends of identical triaxial composition using a kaolin B consisting of ‘higher-crystallinity’ kaolinite or a finer halloysitic kaolin M of lower crystal order was performed. No significant changes in the average Al2O3 contents (near the stoichiometric composition 3:2) of the mullites were observed. Fast and slow firing at the same temperature using B or M kaolin yielded different mullite contents. The Warren–Averbach method showed increase of the D110 mullite crystallite size and crystallite size distributions with small shifts to greater values with increasing firing temperature for the same type of firing (slow or fast) using the same kaolin, as well as significant differences between fast and slow firing of the same blend at different temperatures for each kaolin. The higher maximum frequency distribution of crystallite size observed at the same firing temperature using blends with M kaolin suggests a clearer crystallite growth of mullite in this blend. The agreement between thickening perpendicular to prism faces and mean crystallite sizes <D110> of mullite were not always observed because the direction perpendicular to 110 planes is not preferred for growth.

Dislocation Densities in Dispersion-Strengthened Copper with Aluminum Oxide from X-Ray Line Profile Analysis

2018 ◽  
Vol 941 ◽  
pp. 2024-2029
Author(s):  
Mutsumi Sano ◽  
Sunao Takahashi ◽  
Atsuo Watanabe ◽  
Ayumi Shiro ◽  
Takahisa Shobu ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Aluminum Oxide ◽  
Ambient Temperature ◽  
Line Profile ◽  
Profile Analysis ◽  
Compressive Strain ◽  
Line Profile Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dislocation Densities

Dislocation densities of dispersion-strengthened copper with aluminum oxide, namely GlidCop were evaluated employing the X-ray line profile analysis using the modified Williamson-Hall and modified Warren-Averbach method. X-ray diffraction profiles for GldCop samples with compressive strains applied at ambient temperature were measured with synchrotron radiation. The dislocation densities of GlidCop with compressive strain ranging from 0 – 2.7 % were on the order of 1.5×1014 – 6.6×1014 m-2.

Dislocation Density of Plastically Deformed Oxygen-Free Copper

2017 ◽  
Vol 905 ◽  
pp. 60-65
Author(s):  
Mutsumi Sano ◽  
Sunao Takahashi ◽  
Atsuo Watanabe ◽  
Ayumi Shiro ◽  
Takahisa Shobu
Keyword(s):  
Synchrotron Radiation ◽  
Dislocation Density ◽  
Profile Analysis ◽  
Plastic Strains ◽  
X Ray Diffraction ◽  
Diffraction Profile ◽  
X Ray ◽  
Dislocation Densities

The dislocation density of plastically deformed oxygen free copper (OFC) was evaluated by X-ray diffraction profile analysis with synchrotron radiation. The modified Williamson-Hall and modified Warren-Averbach methods were applied to the analysis. The dislocation densities of OFC samples with compressive plastic strains of 1 % and 4 % were 5.1×1014 m-2 and 9.2×1014 m-2, respectively.

scholarly journals Crystallite size distribution and dislocation structure determined by diffraction profile analysis: principles and practical application to cubic and hexagonal crystals

2001 ◽  
Vol 34 (3) ◽  
pp. 298-310 ◽  
Author(s):  
T. Ungár ◽  
J. Gubicza ◽  
G. Ribárik ◽  
A. Borbély
Keyword(s):  
Crystallite Size ◽  
Size Distribution ◽  
Fourier Coefficients ◽  
Profile Analysis ◽  
Nanocrystalline Powder ◽  
Dislocation Model ◽  
Size Distributions ◽  
Strain Anisotropy ◽  
Diffraction Profile ◽  
X Ray

Two different methods of diffraction profile analysis are presented. In the first, the breadths and the first few Fourier coefficients of diffraction profiles are analysed by modified Williamson–Hall and Warren–Averbach procedures. A simple and pragmatic method is suggested to determine the crystallite size distribution in the presence of strain. In the second, the Fourier coefficients of the measured physical profiles are fitted by Fourier coefficients of well establishedab initiofunctions of size and strain profiles. In both procedures, strain anisotropy is rationalized by the dislocation model of the mean square strain. The procedures are applied and tested on a nanocrystalline powder of silicon nitride and a severely plastically deformed bulk copper specimen. The X-ray crystallite size distributions are compared with size distributions obtained from transmission electron microscopy (TEM) micrographs. There is good agreement between X-ray and TEM data for nanocrystalline loose powders. In bulk materials, a deeper insight into the microstructure is needed to correlate the X-ray and TEM results.

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