Dislocation densities and prevailing slip-system types determined by X-ray line profile analysis in a textured AZ31 magnesium alloy deformed at different temperatures

2013 ◽  
Vol 46 (1) ◽  
pp. 55-62 ◽  
Author(s):  
Bertalan Jóni ◽  
Talal Al-Samman ◽  
Sandip Ghosh Chowdhury ◽  
Gábor Csiszár ◽  
Tamás Ungár
Keyword(s):  
Magnesium Alloy ◽  
Tensile Deformation ◽  
Profile Analysis ◽  
High Angular Resolution ◽  
Line Profile Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dislocation Densities ◽  
Different Temperatures ◽  
Diffraction Patterns

Tension experiments were carried out at room temperature, 473 K and 673 K on AZ31-type extruded magnesium alloy samples. The tensile deformation has almost no effect on the typical extrusion texture at any of the investigated temperatures. X-ray diffraction patterns provided by a high-angular-resolution diffractometer were analyzed for the dislocation density and slip activity after deformation to fracture. The diffraction peaks were sorted into two groups corresponding either to the major or to the random texture components in the specimen. The two groups of reflections were evaluated simultaneously as if the two texture components were two different phases. The dislocation densities in the major texture components are found to be always larger than those in the randomly oriented grain populations. The overwhelming fraction of dislocations prevailing in the samples is found to be of 〈a〉 type, with a smaller fraction of 〈c + a〉-type dislocations. The fraction of 〈c〉-type dislocations is always obtained to be zero within experimental error.

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 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.

Deposition of TiO2 Thin Films Using Magnetron Sputtering

2011 ◽  
Vol 217-218 ◽  
pp. 1743-1746
Author(s):  
Xing Long Guo
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Magnetron Sputtering ◽  
Profile Analysis ◽  
Line Profile Analysis ◽  
Analysis Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Average Grain Size ◽  
Diffraction Patterns

TiO2 with 20nm in diameter have been prepared by using magnetron sputtering technique. The structure of these powers was determined by X-ray diffraction experiments. The average grain size and particle size in these powers were measured by the line profile analysis method of X-ray diffraction patterns and by scan electron microscopy, respectively. The thin films were investigated by using XRD, SEM measurements.

scholarly journals In situ synchrotron X-ray diffraction line-profile analysis of additively manufactured Ti−6Al−4V alloy under tensile deformation

2020 ◽  
Vol 321 ◽  
pp. 03026
Author(s):  
K. Yamanaka ◽  
A. Kuroda ◽  
M. Ito ◽  
M. Mori ◽  
T. Shobu ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Line Profile ◽  
Tensile Deformation ◽  
Profile Analysis ◽  
High Energy ◽  
Line Profile Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Β Phase

In this study, the tensile deformation behavior of an electron beam melted Ti−6Al−4V alloy was examined by in situ X-ray diffraction (XRD) line-profile analysis. The as-built Ti−6Al−4V alloy specimen showed a fine acicular microstructure that was produced through the decomposition of the α′-martensite during the post-melt exposure to high temperatures. Using high-energy synchrotron radiation, XRD line-profile analysis was successfully applied for examining the evolution of dislocation structures not only in the α-matrix but also in the nanosized, low-fraction β-phase precipitates located at the interfaces between the α-laths. The results indicated that the dislocation density was initially higher in the β-phase and an increased dislocation density with increasing applied tensile strain was quantitatively captured in each constitutive phase. It can be thus concluded that the EBM Ti−6Al−4V alloy undergoes a cooperative plastic deformation between the constituent phases in the duplex microstructure. These results also suggested that XRD line-profile analysis combined with highenergy synchrotron XRD measurements can be utilized as a powerful tool for characterizing duplex microstructures in titanium alloys.

scholarly journals Microstructure Characterization in Individual Texture Components by X-Ray Line Profile Analysis: Principles of the X-TEX Method and Practical Application to Tensile-Deformed Textured Ti

Crystals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 691
Author(s):  
Bertalan Jóni ◽  
Éva Ódor ◽  
Mia Maric ◽  
Wolfgang Pantleon ◽  
Tamás Ungár
Keyword(s):  
Line Profile ◽  
Profile Analysis ◽  
Subgrain Size ◽  
Pure Titanium ◽  
Evaluation Procedure ◽  
Line Profile Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dislocation Densities ◽  
Diffraction Peaks

A novel X-ray diffraction-based method and computer program X-TEX has been developed to determine the microstructure in individual texture components of polycrystalline, textured materials. Two different approaches are presented. In the first one, based on the texture of the specimen, the X-TEX software provides optimized specimen orientations for X-ray diffraction experiments in which diffraction peaks consist of intensity contributions stemming from grain populations of separate texture components in the specimen. Texture-specific diffraction patterns can be created by putting such peaks together from different measurements into an artificial pattern for each texture component. In the second one, the X-TEX software can determine the intensity contributions of different texture components to diffraction peaks measured in a particular sample orientation. According to this, peaks belonging mainly to one of the present texture components are identified and grouped into the same quasi-phase during the evaluation procedure. The X-TEX method was applied and tested on tensile-deformed, textured, commercially pure titanium samples. The patterns were evaluated by the convolutional multiple whole profile (CMWP) procedure of line profile analysis for dislocation densities, dipole character, slip systems and subgrain size for three different texture components of the Ti specimens. Significant differences were found in the microstructure evolution in the two major and the random texture components. The dislocation densities were discussed by the Taylor model of work hardening.

Dislocation Densities, Slip-System Types and Burgers Vector Populationsinhexagonal and Cubiccrystalsfrom X-Ray Line Profile Analysis

2011 ◽  
Vol 702-703 ◽  
pp. 479-484
Author(s):  
Tamás Ungár
Keyword(s):  
Line Profile ◽  
Profile Analysis ◽  
Polycrystalline Materials ◽  
Line Profile Analysis ◽  
X Ray Diffraction ◽  
Burgers Vector ◽  
X Ray ◽  
Diffraction Line Profile ◽  
Vector Population ◽  
Dislocation Densities

X-ray diffraction line profile analysis can be carried out on the hkl planes corresponding to the same texture component or the same crystallographic orientation fiber. It is shown that in textured polycrystalline materials or in thin films or multilayers X-ray line profiles measured on planes corresponding either to the main or the minor texture components can provide the Burgers vector population and dislocations densities in the different texture components separately. The experimental technique is outlined for textured specimens and the multiple convolutional whole profile method, i.e. the CMWP line profile analysis procedure, is presented for its capacity to determine the substructure pertaining to different texture components in textured samples.

Twinning on pyramidal planes in hexagonal close packed crystals determined along with other defects by X-ray line profile analysis

2009 ◽  
Vol 42 (4) ◽  
pp. 580-591 ◽  
Author(s):  
Levente Balogh ◽  
Géza Tichy ◽  
Tamás Ungár
Keyword(s):  
Crystallite Size ◽  
Profile Analysis ◽  
Line Profile Analysis ◽  
Slip Systems ◽  
Line Broadening ◽  
X Ray ◽  
Hexagonal Close Packed ◽  
Dislocation Densities ◽  
Different Temperatures ◽  
Active Slip

A systematic procedure is developed to evaluate the frequency of {10.1}〈10.\overline 2〉 and {11.2}〈11.\overline 3〉 compressive twins and {10.2}〈10.\overline 1〉 and {11.1}〈\overline 1\overline 1.6〉 tensile twins together with dislocation densities, active slip systems and crystallite size in hexagonal close packed (hcp) metals. The effect of pyramidal twinning on X-ray line broadening in hcp metals is fundamentally different from the effect of twinning on close packed planes in face centred cubic (fcc) crystals. Therefore, the usual theoretical descriptions developed previously for fcc crystals cannot be used for pyramidal twinning in hcp crystals. The profile functions of sub-reflections for this type of twinning are derived to be the sum of a symmetrical and an antisymmetrical Lorentzian function. Sub-profile properties are parameterized and the parameter files are incorporated into the convolutional multiple whole profile (CMWP) procedure. The extended procedure,eCMWP, is applied to determine pyramidal twin frequencies together with dislocation densities, active slip systems and crystallite size in Mg deformed at different temperatures, in commercial purity Ti deformed at high temperature and in high-purity Ti deformed at room temperature.

Twinning, Dislocations and Grain Size in NanoSPD Materials Determined by X-Ray Diffraction

2008 ◽  
Vol 584-586 ◽  
pp. 571-578 ◽  
Author(s):  
Tamás Ungár ◽  
L. Balogh ◽  
Gábor Ribárik
Keyword(s):  
Line Profile ◽  
Profile Analysis ◽  
Line Profile Analysis ◽  
Line Broadening ◽  
X Ray Diffraction ◽  
Systematic Analysis ◽  
Planar Defects ◽  
X Ray ◽  
Dislocation Densities ◽  
And Shifts

High resolution X-ray line profile analysis is sensitive to crystallite size, dislocation densities and character, and to planar defects, especially stacking faults or twinning. The different effects of microstructure features can be evaluated separately on the basis of the different corresponding profile functions and the different hkl dependences of line broadening. Profiles of faulted crystals consist of sub-profiles broadened and shifted according to different hkl conditions. The systematic analysis of the breadts and shifts of sub-profiles enables X-ray line profile analysis by using defect related profile functions corresponding to: (i) size, (ii) strain and (iii) planar faults, respectively. It is shown that twinning can either be enhanced or weakened by severe plastic deformation.

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