Study of Residual Stress Relaxation Using X-Ray Diffraction

2004 ◽  
Vol 274-276 ◽  
pp. 871-876 ◽  
Author(s):  
Wun Chet Davy Cheong ◽  
W.Z. Zhuang ◽  
Liang Chi Zhang
Keyword(s):  
Residual Stress ◽  
Stress Relaxation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Residual Stress Relaxation

Thermal Residual Stress Relaxation in Sputtered ZnO Film on (100) Si Substrate Studied In Situ by Synchrotron X-Ray Diffraction

2011 ◽  
Vol 681 ◽  
pp. 127-132
Author(s):  
Christopher Krauss ◽  
Guillaume Geandier ◽  
Florine Conchon ◽  
Pierre Olivier Renault ◽  
Eric Le Bourhis ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stress Relaxation ◽  
Structural Changes ◽  
Zno Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Si Substrates ◽  
Compressive Stresses ◽  
Residual Stress Relaxation

Residual stress relaxation in sputtered ZnO films has been studied in-situ by synchrotron x-ray diffraction. The films deposited on (001) Si substrates were thermally treated from 25°C to 700°C. X-ray diffraction 2D patterns were captured continuously during the heating, plateau and cooling ramps. The corrections carried out for compensating the furnace drift are discussed. We first observe an increase of the intrinsic compressive stresses before stress relaxation starts to operate around 370°C. Then, thermal contraction upon cooling dominates so that overall, the large initial compressive film stresses turn to tensile after thermal treatment. The overall behaviour is discussed in terms of structural changes induced by the heat treatment.

scholarly journals Micro-Hardness and Residual Stress Relaxation of 2024 T351 Aluminum Alloy

2011 ◽  
Vol 462-463 ◽  
pp. 343-348 ◽  
Author(s):  
Omar Suliman Zaroog ◽  
Aidy Ali ◽  
Sahari B. Barkawi ◽  
Rizal Zahari
Keyword(s):  
Residual Stress ◽  
Aluminum Alloy ◽  
Stress Relaxation ◽  
Shot Peening ◽  
X Ray Diffraction ◽  
Initial State ◽  
Load Amplitude ◽  
Initial Residual Stress ◽  
Residual Stress Relaxation ◽  
Two Stages

The residual stress relaxation can be divided into two stages: The first cycle relaxation and the following cycles. In both stages, residual stress relaxed considerably from the initial state. The aim of this study is to investigate the residual stress relaxation and microhardness reduction after first and second cyclic load. A 2024 T351 aluminum alloy specimens were shot peened into three shot peening intensities. The fatigue test for first and second cyclic loads of two loads 15.5 kN and 30 kN was performed. The initial residual stress and residual stress after the first and second cycle stress was measured for the three shot peening intensities using X-ray diffraction. Microhardness test was performed for each specimen. The results showed that the residual stress relaxation for first cycle was reached more than 40% of the initial residual stress and it depends on the load amplitude, and microhardness decreased for the first cycle reached 22% and also it depended on load amplitude.

Experimental Comparison of In-Depth Residual Stresses Measured with Neutron and X-Ray Diffraction with a Numerical Stress Relaxation Correction Method

2017 ◽  
Vol 905 ◽  
pp. 131-136
Author(s):  
Bruno Levieil ◽  
Florent Bridier ◽  
Cédric Doudard ◽  
Vincent Klosek ◽  
David Thévenet ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stress Relaxation ◽  
Neutron Diffraction ◽  
Residual Stresses ◽  
Correction Method ◽  
Experimental Comparison ◽  
X Ray Diffraction ◽  
Element Analysis ◽  
Notched Specimen ◽  
X Ray

This study is an experimental comparison of in-depth X-ray diffraction residual stress measurements with neutron diffraction measurements. The goal is to evaluate the relevance of the Savaria-Bridier-Bocher [1] stress relaxation correction method. Neutron diffraction are performed on a bent notched specimen. Destructive X-ray diffraction is performed until 5.25mm below the surface by polishing the material. This polishing induces stress relaxation and X-ray diffraction results have to be corrected. For that purpose, a finite element analysis is realised and show good correlation with neutron measurements results. The application of the stress correction method improves the X-ray measurements especially after 2 mm below the surface. The differences between measured and corrected residual stresses from both diffraction techniques are analyzed and discussed.

scholarly journals Material Removal, Correction and Laboratory X-Ray Diffraction

2014 ◽  
Vol 996 ◽  
pp. 181-186 ◽  
Author(s):  
Eric Wasniewski ◽  
Baptiste Honnart ◽  
Fabien Lefebvre ◽  
Eric Usmial
Keyword(s):  
Residual Stress ◽  
Stress Relaxation ◽  
Stress Field ◽  
Residual Stresses ◽  
Material Removal ◽  
Stress Gradient ◽  
X Ray Diffraction ◽  
X Ray ◽  
Surface Residual Stresses ◽  
Residual Stress Gradient

Laboratory X-ray diffraction is commonly used for surface residual stresses determination. Nevertheless, the in-depth residual stress gradient also needs to be known. Chemical or electro-polishing method is generally used for material removal. However, material removal may seek a new equilibrium and stress field may change in such a way that experimental residual stress values must be corrected. Different methods exist to account for the residual stress relaxation associated with the material removal operation and will be discussed in this paper.

scholarly journals The Effect of Specimen Dimension on Residual Stress Relaxation of the Weldments

2014 ◽  
Vol 996 ◽  
pp. 820-826 ◽  
Author(s):  
Zhong Yuan Qian ◽  
Scott Chumbley ◽  
Eric Johnson
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stress Relaxation ◽  
Finite Element Modeling ◽  
Empirical Model ◽  
Stress Measurement ◽  
Relaxation Behavior ◽  
Stress Relaxation Behavior ◽  
X Ray ◽  
Residual Stress Relaxation

The purpose of this study is to evaluate the residual stress relaxation behavior in weldments. The stress relaxation is studied while successively reducing the size of weld specimens. Finite-element modeling was used to simulate the stress relaxation, and then an empirical model was derived based on the experimental and modeling results. The results of this study shall encourage industry users to utilize more plentiful conventional X-ray diffractometers for residual stress measurement of large weld components.

Stress Relaxation Mechanism after Thinning Process on 4H-SiC Substrate

2018 ◽  
Vol 924 ◽  
pp. 535-538
Author(s):  
Ruggero Anzalone ◽  
Nicolò Piluso ◽  
Grazia Litrico ◽  
Simona Lorenti ◽  
Giuseppe Arena ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stress Relaxation ◽  
Relaxation Mechanism ◽  
Post Processing ◽  
X Ray Diffraction ◽  
Final Thickness ◽  
X Ray ◽  
Before And After ◽  
Thinning Process ◽  
Koh Etching

In this work a comparison between different 6 inches 4H-SiC commercial substrates after post processing has been shown. The main comparison was done between two different suppliers after a thinning process that leaves the sample with a final thickness of 150 microns. After the processing the two substrates show different behavior with different curvature and residual stress. X-Ray diffraction show different crystal quality and curvature values of the substrates. Micro-Raman show different residual stress of the substrates before and after the thinning process. Moreover, molten KOH etching for dislocation detection also show different value of dislocation density for both substrates.

Comparative study of the effective parameters on residual stress relaxation in welded aluminum plates under cyclic loading

2020 ◽  
Vol 21 (5) ◽  
pp. 505
Author(s):  
Yousef Ghaderi Dehkordi ◽  
Ali Pourkamali Anaraki ◽  
Amir Reza Shahani
Keyword(s):  
Residual Stress ◽  
Cyclic Loading ◽  
Stress Relaxation ◽  
Stress Amplitude ◽  
Cyclic Plasticity ◽  
Mean Stress ◽  
Effective Parameters ◽  
Perfect Plasticity ◽  
Residual Stress Relaxation ◽  
Aluminum Plates

The prediction of residual stress relaxation is essential to assess the safety of welded components. This paper aims to study the influence of various effective parameters on residual stress relaxation under cyclic loading. In this regard, a 3D finite element modeling is performed to determine the residual stress in welded aluminum plates. The accuracy of this analysis is verified through experiment. To study the plasticity effect on stress relaxation, two plasticity models are implemented: perfect plasticity and combined isotropic-kinematic hardening. Hence, cyclic plasticity characterization of the material is specified by low cycle fatigue tests. It is found that the perfect plasticity leads to greater stress relaxation. In order to propose an accurate model to compute the residual stress relaxation, the Taguchi L18 array with four 3-level factors and one 6-level is employed. Using statistical analysis, the order of factors based on their effect on stress relaxation is determined as mean stress, stress amplitude, initial residual stress, and number of cycles. In addition, the stress relaxation increases with an increase in mean stress and stress amplitude.

scholarly journals Statistical analysis of the reproducibility of residual stress measurements in cold extruded parts

2021 ◽  
Author(s):  
Fabian Jaeger ◽  
Alessandro Franceschi ◽  
Holger Hoche ◽  
Peter Groche ◽  
Matthias Oechsner
Keyword(s):  
Residual Stress ◽  
Statistical Analysis ◽  
Stress Measurement ◽  
Industrial Applications ◽  
Cold Extrusion ◽  
X Ray Diffraction ◽  
Forming Process ◽  
X Ray ◽  
Stress States ◽  
Key Aspects

AbstractCold extruded components are characterized by residual stresses, which originate from the experienced manufacturing process. For industrial applications, reproducibility and homogeneity of the final components are key aspects for an optimized quality control. Although striving to obtain identical deformation and surface conditions, fluctuation in the manufacturing parameters and contact shear conditions during the forming process may lead to variations of the spatial residual stress distribution in the final product. This could lead to a dependency of the residual stress measurement results on the relative axial and circumferential position on the sample. An attempt to examine this problem is made by the employment of design of experiments (DoE) methods. A statistical analysis of the residual stress results generated through X-Ray diffraction is performed. Additionally, the ability of cold extrusion processes to generate uniform stress states is analyzed on specimens of austenitic stainless steel 1.4404 and possible correlations with the pre-deformed condition are statistically examined. Moreover, the influence of the coating, consisting of oxalate and a MoS2 based lubricant, on the X-Ray diffraction measurements of the surface is investigated.

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