Non-destructive evaluation of residual stresses in thin films via x-ray diffraction topography methods

1991 ◽  
Vol 20 (7) ◽  
pp. 819-825 ◽  
Author(s):  
J. Tao ◽  
L. H. Lee ◽  
J. C. Bilello
Keyword(s):  
Thin Films ◽  
Residual Stresses ◽  
X Ray Diffraction ◽  
X Ray ◽  
Non Destructive Evaluation ◽  
Non Destructive

Influence of deposition parameters on the residual stresses of WC-Wo sputtered thin films

MRS Advances ◽  
2020 ◽  
Vol 5 (23-24) ◽  
pp. 1215-1223
Author(s):  
R.R. Phiri ◽  
O.P. Oladijo ◽  
E.T. Akinlabi
Keyword(s):  
Thin Films ◽  
Residual Stress ◽  
Residual Stresses ◽  
Substrate Surface ◽  
Tribological Performance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Compressive Stresses ◽  
Deposition Parameters ◽  
Cobalt Thin Films

AbstractControl and manipulation of residual stresses in thin films is a key for attaining coatings with high mechanical and tribological performance. It is therefore imperative to have reliable residual stress measurements methods to further understand the dynamics involved. The sin2ψ method of X-ray diffraction was used to investigate the residual stresses on the tungsten carbide cobalt thin films deposited on a mild steel surface to understand the how the deposition parameters influence the generation of residual stresses within the substrate surface. X-ray spectra of the surface revealed an amorphous phase of the thin film therefore the stress measured was of the substrate surface and the effects of sputtering parameters on residual stress were analysed. Compressive stresses were identified within all samples studied. The results reveal that as the sputtering parameters are varied, the residual stresses also change. Optimum deposition parameters in terms of residual stresses were suggested.

X-ray diffraction analysis of residual stresses in textured ZnO thin films

2017 ◽  
Vol 395 ◽  
pp. 16-23 ◽  
Author(s):  
E. Dobročka ◽  
P. Novák ◽  
D. Búc ◽  
L. Harmatha ◽  
J. Murín
Keyword(s):  
Thin Films ◽  
Residual Stresses ◽  
Diffraction Analysis ◽  
Zno Thin Films ◽  
X Ray Diffraction ◽  
X Ray

Three-dimensional welding residual stresses evaluation based on the eigenstrain methodology via X-ray measurements at the surface

2014 ◽  
Vol 03 (04) ◽  
pp. 1450023
Author(s):  
Masaru Ogawa
Keyword(s):  
Neutron Diffraction ◽  
Residual Stresses ◽  
Three Dimensional ◽  
Strain Gauges ◽  
X Ray Diffraction ◽  
Stress Evaluation ◽  
X Ray ◽  
Residual Strains ◽  
Non Destructive ◽  
Evaluation Accuracy

In order to assure structural integrity for operating welded structures, it is necessary to evaluate crack growth rate and crack propagation direction for each observed crack non-destructively. Here, three dimensional (3D) welding residual stresses must be evaluated to predict crack propagation. Today, X-ray diffraction is used and the ultrasonic method has been proposed as non-destructive method to measure residual stresses. However, it is impossible to determine residual stress distributions in the thickness direction. Although residual stresses through a depth of several tens of millimeters can be evaluated non-destructively by neutron diffraction, it cannot be used as an on-site measurement technique. This is because neutron diffraction is only available in special irradiation facilities. Author pays attention to the bead flush method based on the eigenstrain methodology. In this method, 3D welding residual stresses are calculated by an elastic Finite Element Method (FEM) analysis from eigenstrains which are evaluated by an inverse analysis from released strains by strain gauges in the removal of the reinforcement of the weld. Here, the removal of the excess metal can be regarded as non-destructive treatment because toe of weld which may become crack starters can be eliminated. The effectiveness of the method has been proven for welded plates and pipes even with relatively lower bead height. In actual measurements, stress evaluation accuracy becomes poorer because measured values of strain gauges are affected by processing strains on the machined surface. In the previous studies, the author has developed the bead flush method that is free from the influence of the affecting strains by using residual strains on surface by X-ray diffraction. However, stress evaluation accuracy is not good enough because of relatively poor measurement accuracy of X-ray diffraction. In this study, a method to improve the estimation accuracy of residual stresses in this method is formulated, and it is shown numerically that inner welding residual stresses can be estimated accurately from the residual strains measured by X-ray diffraction.

X-Ray Diffraction and TEM Studies of the Delamination of Copper Thin Films from Glass and Silica Substrates

1989 ◽  
Vol 167 ◽  
Author(s):  
Alan G. Fox ◽  
Rowland M. Cannon
Keyword(s):  
Thin Films ◽  
Residual Stresses ◽  
Bragg Diffraction ◽  
Slight Reduction ◽  
X Ray Diffraction ◽  
Dislocation Generation ◽  
X Ray ◽  
Cu Films ◽  
Glass Substrates ◽  
Tensile Strains

AbstractThe events associated with fractures along interfaces between copper thin films and glass substrates were investigated by X-ray diffraction and transmission electron microscopy (TEM). In the as-bonded films the Bragg diffraction lines were shifted and broadened (relative to pure strain-free copper) due to residual in-plane tensile strains arising from the differences in thermal contraction between the copper and the substrates; TEM studies of these films in cross-section showed that the residual stresses had been relieved somewhat by dislocation densities as high as 1010 lines/cm2 in Cu/SiO2 films.The passage of a crack along the Cu/glass interfaces led to a significant reduction in the line shift and a slight reduction in the line broadening. Thus dislocations generated by the fracture events ‘plastically relaxed’ the residual stresses present in the as-bonded Cu by superposing a compressive component onto the pre-existing in-plane tensile strains. This dislocation generation was confirmed by TEM studies. In addition, it was found that the greater the strength of an interface, the greater was the reduction in mean strain due to the fracture; this is consistent with a larger crack-tip plastic zone and the generation of greater numbers of dislocations in the Cu films by fracture along interfaces of higher toughness (i.e. bond strength).

scholarly journals X-Ray Diffraction Analysis of Residual Stresses in the Premium Rails Welded by Flash Butt Process

2020 ◽  
Vol 25 ◽  
Author(s):  
Bras Senra de Oliveira ◽  
Lino Alberto Soares Rodrigues ◽  
Ednelson Silva Costa ◽  
Eduardo de Magalhães Braga ◽  
Marcos Allan Leite dos Reis
Keyword(s):  
Residual Stresses ◽  
Stress Measurement ◽  
Surface Hardness ◽  
Welding Process ◽  
X Ray Diffraction ◽  
Butt Welding ◽  
X Ray ◽  
Compressive Stresses ◽  
Non Destructive ◽  
Welding Technique

Abstract: This work is distinguished by searching for a non-destructive technology, and X-ray diffraction was validated by the XStress 3000 analyser. Measurements of residual stresses in the welded zone of premium pearlitic rails was performed, rail surface hardness of 370 HB and 0.79% carbon content. The welding of the rails was done by flash butt process, performed by Schlatter GAAS 80 stationary equipment. The results of the tensile and compressive stress measurements identified the residual stresses in the welded zone, with specific zones of tensile stresses misplaced at the weld center, with values up to 391 MPa, and compressive stresses, with values up to -166 MPa, as it moves away rails weld center. An important point of this study is the residual stress measurement considering a complete welding process, including: pre-grinding, flash butt welding, heat treatment, finishing grinding and straightening. Lastly, was observed the welding technique potentially can induce residual stresses at rails.

Evolution of Residual Stresses in Thin Films Deposited on Mechanically Strained Substrates

1990 ◽  
Vol 203 ◽  
Author(s):  
G. Sheikh ◽  
A. Berger ◽  
I. C. Noyan
Keyword(s):  
Thin Films ◽  
Simple Model ◽  
Residual Stresses ◽  
Vapor Phase ◽  
X Ray Diffraction ◽  
Total Stress ◽  
X Ray ◽  
Cu Films ◽  
Residual Film ◽  
Nickel Substrates

ABSTRACTA simple model for the formation of residual stresses in thin films deposited on elastically strained substrates was derived and experimentally tested. In the experiments, Cu thin films were deposited on elastically stretched nickel substrates. These Cu films were2 to 4.m thick and were deposited through vapor phase evaporation or electroplating. The loads applied during the deposition were then relaxed, and the total stress in both the film and the substrate were monitored (by x-ray diffraction) during this relaxation. It was seen that the final (residual) film stresses were significantly different for bothdeposition methods. The causes of such differences are discussed.

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