The Experimental Study of Diffraction Angle of Aluminum Alloy 3003

2012 ◽  
Vol 625 ◽  
pp. 291-296
Author(s):  
Neng Quan Duan ◽  
Jian Liang Ren ◽  
Rui Qiang Pang
Keyword(s):  
Residual Stress ◽  
Aluminum Alloy ◽  
Stress Measurement ◽  
Electrical Measuring ◽  
Diffraction Method ◽  
Measuring Method ◽  
X Ray ◽  
Equal Strength ◽  
Diffraction Angle ◽  
Stress Measuring

The most suitable diffraction angle of aluminum alloy 3003 used for stress measuring is aimed to be determined in this paper. The experiment makes a stress measurement of a loading aluminum alloy 3003 equal strength beam with the traditional electrical measuring method and the X-ray stress measurement. With the electrical measuring method as reference, the research study the measured values that acquired from the X-ray diffraction method when the diffraction angle are 142° and 156°, and then compare them with that acquired from electrical measuring method. The measurement results demonstrate that the diffraction angle at 156 ° is better than at 142 ° based on the assessment standards of the liner slope and the distribution of data. Thus the optimum diffraction angle for X-ray to measure the macroscopic stress of aluminum alloy 3003 is 156 °. In this paper，the stress caused by the load on the equal strength beam is assumed to be "residual stress" and thus the conclusion has reference values for the standardization of residual stress measurement of aluminum alloy by XRD and has theoretical guiding significance in the production practices.

Performance evaluation and optimization of X-ray stress measurement for nickel aluminium bronze based on the Bayesian method

2016 ◽  
Vol 49 (2) ◽  
pp. 389-398 ◽  
Author(s):  
Yanhui Zhang ◽  
Wenyu Yang ◽  
Kemao Lv
Keyword(s):  
Residual Stress ◽  
Stress Measurement ◽  
Bragg Diffraction ◽  
Random Disturbance ◽  
Measuring Instrument ◽  
X Ray ◽  
Aluminium Bronze ◽  
Diffraction Angle ◽  
Model Class ◽  
Stress Measuring

Nickel aluminium bronze is the main material of the controllable pitch propeller in the dynamic positioning system of an ocean-going vessel. When using an X-ray stress measuring instrument to measure the residual stress in this material, measurement failure phenomena often appear since the X-ray diffraction profile of nickel aluminium bronze has a low signal-to-noise ratio. Therefore, the Bragg diffraction angle identified by the traditional method has a large uncertainty, which could cause a large random disturbance of the X-ray stress measurement. Considering the measurement noise and model error, a new approach based on the Bayesian model class framework is proposed to improve the performance of current X-ray stress measurement analysis. For model classes with different peak shape functions, the posterior distributions of the Bragg diffraction angle 2θB are identified first, the posterior probabilities of each model class are computed, a hyper-robust value of 2θB is obtained and finally the residual stress is calculated. Using the confidence intervals of 2θB, the uncertainty of the X-ray stress measuring instrument at each measurement can be determined. Several experiments show that the performance of the proposed method is better than that of the current instrumental method. Of course, the proposed method is also suitable for the residual stress measurement of other new materials and is not limited to nickel aluminium bronze.

Research on Stress Calibration Technology on Aluminum of High-Speed Train Body Structure by Nondestructive X-Ray Method Measurement

2011 ◽  
Vol 189-193 ◽  
pp. 734-742
Author(s):  
Hua Ji ◽  
Hui Chen ◽  
Guo Qing Gou ◽  
Da Li ◽  
Yan Liu ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
High Speed ◽  
Stress Measurement ◽  
Diffraction Method ◽  
Welding Residual Stress ◽  
X Ray Diffraction ◽  
Ray Method ◽  
Electrometric Method ◽  
X Ray ◽  
6082 Aluminum Alloy

X-ray diffraction method has been employed to calibrate the stress of 6082 aluminum alloy which has been widely used among modern industrial products. Based on elastic tensile conditions, by designing rod sample of uniform intensity calibration (RSUIC), the stress measurement by X-ray diffraction method has been verificated by using elastic tensile theory calculation method and electrometric method. The results show that the stress measured by the tensile stress theoretical calculation, electrometric method and X-ray diffraction method was in good accordance with each other. And the matching relation between the surface stress measured by X-ray diffraction and the internal stress is investigated. The research will lay a foundation for the application of iXRD stress instrument for nondestructive measuring the welding residual stress of aluminum alloy.

Errors in Residual Stress Measurements due to Random Counting Statistics

1970 ◽  
Vol 14 ◽  
pp. 377-388 ◽  
Author(s):  
C. J. Kelly ◽  
M. A. Short
Keyword(s):  
Residual Stress ◽  
Standard Deviation ◽  
Stress Measurement ◽  
Mathematical Expression ◽  
X Ray Diffraction ◽  
Intensity Maximum ◽  
X Ray ◽  
Diffraction Angle ◽  
Data Points ◽  
Counting Statistics

AbstractThe measurement of residual stress, using X-ray diffraction techniques, is based on the change in diffraction angle determined for the Intensity maximum of some suitable reflection from the sample when this is placed consecutively with its surface at two different angles to the diffracting planes. These diffraction angles may be obtained in a variety of ways, but are most often calculated from measurements of three X-ray diffraction intensities at angles selected in the immediate vicinity of the peak maximum at each sample angle and fitting each set of data to a parabolic curve. A simple mathematical expression may be derived relating the diffraction angles, and hence the residual stress, to the measured X-ray intensities; there will, however, be statistical errors in the calculated diffraction angles due to random counting errors in the measurement of the X-ray diffraction intensities. From the expression relating the residual stress to the X-ray intensities an equation has been derived giving the standard deviation in the residual stress due to random counting errors. In addition, a simple approximation has been obtained from this equation showing that the standard deviation is decreased by increasing the number of counts accumulated for each X-ray intensity measurement and by increasing the size of the angular increments between the data points. It will also be shown that, using the approximation, it is possible to estimate in advance the number of accumulated counts at each point necessary to attain a desired standard deviation in a residual stress measurement.

Technology development for in-situ measurement of residual stress in arc welded joints of MDN 250 by portable Cosα X-ray diffraction method

2021 ◽  
pp. 095440892110590
Author(s):  
Bibin Jose ◽  
Manikandan Manoharan ◽  
Arivazhagan Natarajan
Keyword(s):  
Residual Stress ◽  
Welded Joints ◽  
Stress Measurement ◽  
Quantitative Estimation ◽  
Diffraction Method ◽  
X Ray Diffraction ◽  
Metallic Component ◽  
Substantial Impact ◽  
X Ray ◽  
Stress Measurements

Residual stresses are inherent stresses that exist in engineering components even though no external load is applied. They are caused by the non-uniform volumetric shift of the metallic component during manufacturing processes. Welding is a key manufacturing technique that has a substantial impact on the economy since it is required for the production of a diverse variety of products used in the engineering sector. The residual stress primarily affects the stability, durability and performance of the welded joints. Hence its determination is of utmost importance. X-ray diffraction (XRD) is the most commonly used method for residual stress analysis. There are mainly two approaches for measuring residual stress using XRD; one is the sin2ψ method and the other is the cosα method. The residual stress measurements using the cosα method are handy, quick and convenient compared to the sin2ψ method. This method is well suited for welded joints, as it provides flexibility for testing immediately after the welding operation. Apart from residual stress measurements, the cosα method also gives valuable insights in the form of Debye-Scherrer (DS) rings and full width at half maximum. The present study focuses on the development of a novel technique that not only enables residual stress measurement but also provides a quantitative estimation of hardness and qualitative estimation of grain size without performing metallurgical or mechanical characterization. The material used for the present study is an arc-welded joint of MDN 250 grade maraging steel. The residual stress results show a compressive profile throughout the weldment, with a maximum value of compressive residual stress of 428 MPa at the fusion zone.

Sign in / Sign up

Export Citation Format

Share Document