scholarly journals Precision X-Ray Stress Analysis of Uranium and Zirconium

1959 ◽  
Vol 3 ◽  
pp. 331-336
Author(s):  
B. J. Wooden ◽  
Lt. E. C. House ◽  
R. E. Ogilvie
Keyword(s):  
Residual Stresses ◽  
Stress Analysis ◽  
Peak Position ◽  
Diffraction Peak ◽  
X Ray Diffraction ◽  
X Ray ◽  
Least Squares Fit ◽  
Order Polynomial ◽  
Desk Calculator

AbstractThe feasibility of using X-ray diffraction methods to measure residual stresses in uranium and zirconium (Zircaloy-2) was investigated. A precision method was developed for the determination of diffraction peak positions and the precision associated therewith. The statistical tables of Fisher and Yates were used to determine what order polynomial provided the best least squares fit within the known precision of the observed data. It was found that a second-order polynomial provided an adequate regression. With the aid of a desk calculator less than 5 min calculation time is required to determine the peak position to a precision of ±0.01°.The stress constant for uranium was determined to be 1308 ± 110 psi/0.01° shift in Δ2θ for copper radiation on the (116) planes at 2θ = 158.3°. The stress constant for Zircaloy-2 was determined to be 430 ± 1 psi/0.01° shift in Δ2θ for chromium radiation on the (10,4) planes at 2θ = 156.4°.

Microbeam X-ray diffraction from twisted lamellar crystals: theory and computer simulation

2009 ◽  
Vol 42 (4) ◽  
pp. 673-680 ◽  
Author(s):  
Valeriy A. Luchnikov ◽  
Dimitri A. Ivanov
Keyword(s):  
Basal Plane ◽  
Peak Position ◽  
Diffraction Peak ◽  
Reciprocal Space ◽  
X Ray Diffraction ◽  
X Ray ◽  
Peak Broadening ◽  
Asymmetric Shape ◽  
Diffraction Peaks ◽  
Lamellar Crystals

The diffraction peak position, width and intensity distribution are calculated for the case of a helicoidally twisted crystalline lamella, both analytically and numerically. It is shown that the diffraction peak broadening depends on the orientation of the corresponding reciprocal-space vector with respect to the helicoid axis and the normal to the lamellar basal plane. The equatorial peaks, which are close to the normal direction to the lamellar basal plane, are characterized by the highest azimuthal width. By contrast, the reflections positioned close to the lamellar surface have the smallest azimuthal width. For non-equatorial peaks in the proximity of the twisting axis the intensity has an unusual asymmetric shape. The shape of the microbeam, as well as its position and direction with respect to the lamella, influences the shape of the diffraction peaks in reciprocal space and their appearance in two-dimensional diffractograms. The proposed approach can be useful, for example, for the interpretation of microbeam diffractograms of banded polymer spherulites.

X-Ray Diffraction Analysis of Steel with Oxidised Surface Layer

2016 ◽  
Vol 368 ◽  
pp. 99-102
Author(s):  
Lukáš Zuzánek ◽  
Ondřej Řidký ◽  
Nikolaj Ganev ◽  
Kamil Kolařík
Keyword(s):  
Residual Stress ◽  
Surface Layer ◽  
Residual Stresses ◽  
Diffraction Analysis ◽  
Oxide Surface ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrolytic Polishing ◽  
Small Depth

The basic principle of the X-ray diffraction analysis is based on the determination of components of residual stresses. They are determined on the basis of the change in the distance between atomic planes. The method is limited by a relatively small depth in which the X-ray beam penetrates into the analysed materials. For determination of residual stresses in the surface layer the X-ray diffraction and electrolytic polishing has to be combined. The article is deals with the determination of residual stress and real material structure of a laser-welded steel sample with an oxide surface layer. This surface layer is created during the rolling and it prevents the material from its corrosion. Before the X-ray diffraction analysis can be performed, this surface layer has to be removed. This surface layer cannot be removed with the help of electrolytic polishing and, therefore, it has to be removed mechanically. This mechanical procedure creates “technological” residual stress in the surface layer. This additional residual stress is removed by the electrolytic polishing in the depth between 20 and 80 μm. Finally, the real structure and residual stresses can be determined by using the X-ray diffraction techniques.

Non-Destructive Residual Stress Analysis of Induction Hardened Components by Neutron and X-Ray Diffraction

2013 ◽  
Vol 768-769 ◽  
pp. 420-427 ◽  
Author(s):  
Jeremy Epp ◽  
Thilo Pirling ◽  
Thomas Hirsch
Keyword(s):  
Residual Stress ◽  
Chemical Composition ◽  
Residual Stresses ◽  
Stress Analysis ◽  
Stress Gradient ◽  
X Ray Diffraction ◽  
Neutron Measurement ◽  
X Ray ◽  
Layer Removal ◽  
Residual Stress Analysis

In this paper the microstructural and residual-stress analysis of an induction hardened plate of medium carbon steel is described. The stress gradient was determined using laboratory X-ray diffraction (IWT, Bremen, Germany) and neutron strain scanning (ILL, Grenoble, France). Due to slight variations of chemical composition in the depth, matchstick like (cross section 2×2mm²) d0-reference samples were prepared from a similarly treated sample. The d0shift induced by variation of chemical composition was measured by neutron and by X-ray diffraction along the strain free direction (sin²ψ*) and used for the evaluation of the neutron stress calculation. The d0distribution obtained from the neutron measurement did not appear reliable while the method using X-ray diffraction seems to be an efficient and reliable method to determine d0profiles in small samples. The evaluation of neutron measurements was then done using the X-ray diffraction d0distribution. High compressive residual stresses were measured in the hardened layer followed by high tensile residual stresses in the core. A comparison of the neutron measurements with X-ray diffraction (XRD) depth profiles obtained after successive layer removal showed that both methods give similar results. However, these investigations opened the question about the direct comparison of the residual stresses obtained by neutron and XRD. Indeed, a correction of the neutron data regarding the residual stresses in thickness direction might be necessary as these are released in the case of X-ray diffraction measurements after layer removal.

scholarly journals Generalised Least-squares Determination of Triaxial Stress States by X-ray Diffraction and the Associated Errors

1988 ◽  
Vol 41 (2) ◽  
pp. 189 ◽  
Author(s):  
RA Winholtz ◽  
JB Cohen
Keyword(s):  
Stress State ◽  
Residual Stresses ◽  
Least Squares ◽  
Triaxial Stress ◽  
X Ray Diffraction ◽  
Triaxial Stress State ◽  
X Ray ◽  
Stress States ◽  
Counting Statistics

The determination of residual stresses via X-ray diffraction is briefly reviewed, with particular emphasis on the triaxial stress state. A new method is proposed for determining the general stress tensor, which considerably reduces the variances of the stresses due to counting statistics and gradients. The procedure involves a generalised least-squares solution of strains measured at various tilts of the X-ray beam to the sample, and a new set of tilts is recommended to minimise these errors.

Residual Stress Measurement of Industrial Polymers by X-Ray Diffraction

2015 ◽  
Vol 1110 ◽  
pp. 100-103
Author(s):  
Doi Taisei ◽  
Masayuki Nishida ◽  
Ozaki Junichi
Keyword(s):  
Residual Stresses ◽  
Measurement Accuracy ◽  
Stress Measurement ◽  
Regression Line ◽  
Polymeric Materials ◽  
Measured Data ◽  
Diffraction Peak ◽  
X Ray Diffraction ◽  
Transmission Method ◽  
X Ray

In this study, residual stresses in polyamide (PA) materials were measured by the x-ray stress measurement technique. X-ray stress measurement is widely used to measure residual stresses, however, this measurement is not many used in polymeric materials. There are two problems for measuring residual stresses in polymer. Firstly, the diffraction peak from the polymer appears at the low 2θangle region. Thus the measurement accuracy for strains reduces. Secondly, the low 2θangle region is very difficult to use the sin2ψmethod. In this study,Ω-diffractometer with transmission method was used to resolve these problems. The measured data was plotted in thed-sin2ψdiagram, and it was coincident with the linear regression line clearly. X-ray elastic constant (XEC) of PA was estimated from these results.

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