New methods for diffraction stress measurement: a critical evaluation of new and existing methods

2000 ◽  
Vol 33 (4) ◽  
pp. 1059-1066 ◽  
Author(s):  
J.-D. Kamminga ◽  
Th. H. de Keijser ◽  
E. J. Mittemeijer ◽  
R. Delhez
Keyword(s):  
Stress Analysis ◽  
Elastic Constants ◽  
Stress Measurement ◽  
Critical Evaluation ◽  
Polycrystalline Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
New Methods

New methods of diffraction stress analysis of polycrystalline materials, consisting of cubic elastically anisotropic crystallites, are proposed and compared with existing methods. Whereas for the existing methods knowledge of the diffraction elastic constants is presupposed, three new methods are presented that require only knowledge of the (macroscopic) mechanical elastic constants. The stress values obtained with these new methods on the basis of the mechanical elastic constants are more reliable than those obtained with the methods on the basis of the diffraction elastic constants. New and existing methods are illustrated by means of measurements of X-ray diffraction from a magnetron-sputtered TiN layer.

Residual Stress Measurement of Silicon Nitride and Silicon Carbide by X-Ray Diffraction Using Gaussian Curve Method

1988 ◽  
Vol 32 ◽  
pp. 459-469 ◽  
Author(s):  
Masanori Kurita ◽  
Ikuo Ihara ◽  
Nobuyuki Ono
Keyword(s):  
Residual Stress ◽  
Single Crystal ◽  
Elastic Constants ◽  
Stress Measurement ◽  
Polycrystalline Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Small Areas ◽  
Curve Method ◽  
The Continuum

The residual stress induced by grinding or some thermal treatment has a large effect on the strength of ceramics. The X-ray technique can be used to nondestructively measure the residual stress in small areas on the surface of polycrystalline materials. The X-ray stress measurement is based on. the continuum mechanics for macroscopically isotropic polycrystalline materials. In this method, the stress value is calculated selectively from strains of a particular diffraction plane in the grains which are favorably oriented for the diffraction. In general, however, the elastic constants of a single crystal depend on the plane of the lattice, since a single crystal is anisotropic, The behavior of the deformation of individual crystals in the aggregate of polycrystalline materials under applied stress has not yet been solved successfully. Therefore, the stress constant and elastic constants for a particular diffracting plane should be determined experimentally in order to determine the residual stress accurately by X-ray diffraction.

Standard Deviations in X-Ray Stress and Elastic Constants Due to Counting Statistics

1988 ◽  
Vol 32 ◽  
pp. 377-388 ◽  
Author(s):  
Masanori Kurita
Keyword(s):  
Elastic Constants ◽  
Stress Measurement ◽  
Steel Specimen ◽  
Polycrystalline Materials ◽  
X Rays ◽  
Confidence Limits ◽  
X Ray Diffraction ◽  
X Ray ◽  
Standard Deviations ◽  
Counting Statistics

AbstractX-ray diffraction can be used to nondestructively measure residual stress of polycrystalline materials. In x-ray stress measurement, it is important to determine a stress constant experimentally in order to measure the stress accurately. However, every value measured by x-ray diffraction has statistical errors arising from counting statistics. The equations for calculating the standard deviations of the stress constant and elastic constants measured by x-rays are derived analytically in order to ascertain the reproducibility of the measured values. These standard deviations represent the size of the variability caused by counting statistics, and can be calculated from a single set of measurements by using these equations. These equations can apply Lu any meuhud for x-ray stress ifiesuremenL. The variances of the x-ray stress and elastic constants are expressed in terms of the linear combinations of the variances of the peak position. The confidence limits of these constants of a quenched and tempered steel specimen were determined by the Gaussian curve method. The 95% confidence limits of the stress constant were -314 ± 25 MFa/deg.

Residual Stress Analysis of Textured Materials by X-Ray Diffraction Method

2012 ◽  
Vol 706-709 ◽  
pp. 1673-1678 ◽  
Author(s):  
Shouichi Ejiri ◽  
Toshihiko Sasaki ◽  
Yukio Hirose
Keyword(s):  
Residual Stress ◽  
Elastic Constant ◽  
Stress Analysis ◽  
Nonlinear Problem ◽  
Elastic Constants ◽  
Lattice Strain ◽  
Stress Measurement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Textured Materials

The residual stress measurement by the conventional X-ray diffraction was formulated on the assumption that a specimen from polycrystalline materials was quasi-isotropic and homogeneous, and the stress was biaxial and almost constant within the X-ray penetration depth. Therefore, it was not available to analyze the stress state of the textured materials by the conventional measurement as a general rule. In resent years, advanced methods have been proposed for the X-ray stress measurement of textured materials. In some methods, it is assumed that the X-ray elastic constant is derived from the crystallite orientation distribution function of textured materials for solving the first anisotropic problem. However, there is a nonlinear problem in the stress analysis from the measured lattice strain. In present study, the X-ray elastic constants were averaged as the expected value around the normal direction of the X-ray diffraction in a similar way. A stress analysis was proposed by differential calculus of the X-ray elastic constant in order to the avoidance of nonlinear problem. The stress analysis was applied to residual stress measurements of a titanium carbide coating film with preferred orientation and a cold-rolled steel with texture. The calculated values of the X-ray elastic constants showed the linearity on some condition for the film. The X-ray stress determination was carried out by the fitting the gradients of the measured lattice strain.

Measuring Residual and Applied Stress using X-Ray Diffraction on Materials with Preferred Orientation and Large Grain Size

1992 ◽  
Vol 36 ◽  
pp. 585-593
Author(s):  
James Pineault ◽  
Michael Brauss
Keyword(s):  
Grain Size ◽  
Stress Measurement ◽  
Preferred Orientation ◽  
Polycrystalline Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Common Solution ◽  
Virtual Window ◽  
The Common ◽  
Comparison Of The Results

AbstractOne of the most difficult tasks in applied and residual stress measurement of polycrystalline materials using x-ray diffraction is dealing with preferred orientation and large grain size.A common solution to large grain size problems has been to choose a larger aperture, but in certain cases this is undesirable and/or impossible. When preferred orientation has been identified as the problem, the common approach has been to choose another diffraction plane or oscillate the x-ray diffraction head during data collection. Remedies such as these can distort the peak breadth and are often not sufficient to totally negate the grain size and preferred orientation effects.A technique described as the “step scan with virtual window” has been developed jointly at MTL (formerly Canmet) and Proto Mfg. Ltd. to deal specifically with the aforementioned effects of grain size and preferred orientation.This paper highlights some of the problems that arise in stress analysis of materials exhibiting preferred orientation and large grain size. Subsequently a comparison of the results obtained using standard diffraction technique, oscillation and the “step scan with virtual window” is made.

Two-Dimensional X-Ray Diffraction for Structure and Stress Analysis

2005 ◽  
Vol 490-491 ◽  
pp. 1-6 ◽  
Author(s):  
Bob B. He ◽  
Ke Wei Xu ◽  
Fei Wang ◽  
Ping Huang
Keyword(s):  
Stress Analysis ◽  
Stress Measurement ◽  
Unit Vector ◽  
Sample Space ◽  
Matrix Transformation ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Texture Measurement ◽  
X Ray ◽  
The Matrix

This paper introduces the recent progress in two-dimensional X-ray diffraction as well as its applications in microstructure and residual stress analysis. Based on the matrix transformation between diffraction space, detector space and sample space, the unit vector of the diffraction vector can be expressed in the sample space corresponding to all the geometric parameters and Bragg conditions. The same transformation matrix can be used for texture and stress analysis. The fundamental equations for both stress measurement and texture measurement are developed with the matrix transformation defined for the two-dimensional diffraction. Stress measurement using twodimensional detector is based on a direct relationship between the stress tensor and the diffraction cone distortion. The two-dimensional detector collects texture data and background values simultaneously for multiple poles and multiple directions.

Diffraction stress analysis of elastic grain interaction in polycrystalline materials

2007 ◽  
Vol 222 (3-4) ◽  
Author(s):  
Udo Welzel ◽  
Eric J. Mittemeijer
Keyword(s):  
Stress Analysis ◽  
Mechanical Behaviour ◽  
Classical Field ◽  
Polycrystalline Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Grain Interaction ◽  
Polycrystalline Solids ◽  
Solid Bodies ◽  
Recent Insight

Recent insight on the elastic grain interaction in polycrystalline solids has been summarized. A breakthrough in this classical field of mechanical behaviour of solid bodies is due to highly accurate (X-ray) diffraction stress analysis. The occurrence of so-called direction-dependent grain interaction,

Different Grain Interaction Models Used for Interpretation of Lattice Strain Data Collected Using Grazing Incidence X-Ray Diffraction

2013 ◽  
Vol 768-769 ◽  
pp. 26-30
Author(s):  
Marianna Marciszko ◽  
Andrzej Baczmański ◽  
Mirosław Wróbel ◽  
Wilfrid Seiler ◽  
Chedly Braham ◽  
...  
Keyword(s):  
Elastic Constants ◽  
Elastic Anisotropy ◽  
Grazing Incidence ◽  
Polycrystalline Materials ◽  
X Ray Diffraction ◽  
Surface Layers ◽  
X Ray ◽  
Grain Interaction ◽  
Ni Alloy ◽  
Strain Data

Multireflection grazing incidence X-ray diffraction (MGIXD) was applied to measure residual stresses in thin surface layers and the problem of X-ray elastic constants (XEC) used for the interpretation of results was studied. To show the influence of the X-ray elastic constants on the interpretation of MGIDX results, polycrystalline materials having low (Ti alloy) and high elastic anisotropy of crystallites (Ni alloy) were investigated.

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