scholarly journals In Situ Synchrotron X-Ray Micro-Diffraction Investigation of Elastic Strains in Laminated Ti-Al Composites

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 668
Author(s):  
Tianbo Yu ◽  
Yan Du ◽  
Guohua Fan ◽  
Rozaliya Barabash ◽  
Dorte Juul Jensen ◽  
...  
Keyword(s):  
Compressive Strain ◽  
Spatial Variations ◽  
External Loading ◽  
Metal Composite ◽  
Tensile Direction ◽  
Mean Values ◽  
X Ray ◽  
Lattice Strains ◽  
Elastic Strains

Spatially resolved elastic strains in the bulk interior of a laminated Ti-Al metal composite were studied during in situ tensile loading at strains up to 1.66% by a synchrotron-based micro-diffraction technique, namely differential aperture X-ray microscopy (DAXM). For both Al and Ti grains, deviatoric elastic strains were estimated based on polychromatic X-ray microbeam diffraction, while lattice strains along the normal direction of the tensile sample were directly measured using monochromatic X-ray microbeam diffraction. The estimated deviatoric strains show large spatial variations, and the mean values are consistent with the external loading conditions, i.e., increasing tensile strain along the tensile direction and increasing compressive strain along the sample normal with increasing loading. The directly measured lattice strains also show large spatial variations, although the magnitude of this variation is smaller than that for the estimated deviatoric strain. The directly measured lattice strains in Ti grains are largely consistent with the external loading, whereas those in Al grains are in contradiction with the external loading. The causes of the experimental results are discussed and related to both the laminated microstructure of the composite material and the limitations of the techniques.

Elastoplastic Deformation and Damage Process in Duplex Steel Studied Using Synchrotron and Neutron Diffraction

2017 ◽  
Vol 905 ◽  
pp. 9-16
Author(s):  
Yu Chen Zhao ◽  
Léa Le Joncour ◽  
Andrzej Baczmański ◽  
Manuel François ◽  
Sebastian Wroński ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Synchrotron Diffraction ◽  
X Ray ◽  
Slip Mechanism ◽  
Lattice Strains ◽  
Duplex Steel ◽  
Consistent Model ◽  
Damage Process ◽  
Crystallographic Planes

In the present work, the mechanical behavior of phases in duplex steel during tensile test was studied. Special interest was taken in the analysis of damage process just before failure. In this aim two diffraction methods: in-situ time of flight neutron diffraction and X-ray synchrotron diffraction were applied. Using diffraction data, the slip mechanism on crystallographic planes during plastic deformation was investigated. In the case of aged UR45N steel, it was found that significant softening caused by damage process was initiated in the ferritic phase. The lattice strains measured in situ by two above mentioned diffraction methods were compared with prediction of the self-consistent model.

Micro-Tensile and Fatigue Testing of Copper Thin Films on Substrates

1998 ◽  
Vol 546 ◽  
Author(s):  
M. Hommel ◽  
O. Kraft ◽  
S. P. Baker ◽  
E. Arzt
Keyword(s):  
Elastic Strain ◽  
Fatigue Testing ◽  
Tensile Tests ◽  
Copper Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Tensile Tester ◽  
Elastic Strains ◽  
External Strain

AbstractA special micro-tensile tester was used to carry out tensile tests of thin copper films on substrates. The elastic strain in the film was measured in-situ using x-ray diffraction and the total strain with an external strain gage. From the elastic strains the stresses in the films were calculated and stress-strain curves were obtained. It was observed that the flow stress increases with decreasing film thickness. The method was also applied to investigate the mechanical behavior of films under cyclic loading.

Electromechanical Properties of Pb(Mg1/3Nb2/3)O3 Thin Film Capacitors

1998 ◽  
Vol 541 ◽  
Author(s):  
G. Catalan ◽  
M.H. Corbett ◽  
R.M. Bowman ◽  
J.M. Gregg
Keyword(s):  
Thin Film ◽  
Compressive Strain ◽  
X Ray Diffraction ◽  
Leakage Currents ◽  
Plan View ◽  
X Ray ◽  
Thin Film Capacitors ◽  
Transmission Electron ◽  
Tensile Strains

AbstractPulsed Laser Deposition was used to grow Pb(Mg1/3Nb2/3)O3 (PMN) thin film planar capacitor structures. PMN crystallography was verified by x-ray diffraction and plan-view Transmission Electron Microscopy (TEM). Capacitance of the thin film structures was measured as a function of temperature and frequency. Leakage current was also measured for each capacitor. A DC field was subsequently applied and crystallographic strain was monitored in-situ by X-ray diffraction. The electromechanical strain was found to strongly depend on the deposition conditions for each capacitor. Tensile strains of ∼0.2% and compressive strains of ∼0.3% parallel to the applied field were measured for capacitors of different oxygen contents and thicknesses. We propose that the compressive strain is caused by the combined effect of joule heating of the capacitor structure, caused by large leakage currents, and epitaxial coupling between substrate and films. Electrostrictive tensile strains are of the same order as observed inbulk.

Insight into the nanostructure of anisotropic cellulose aerogels upon compression

Soft Matter ◽  
2019 ◽  
Vol 15 (41) ◽  
pp. 8372-8380 ◽  
Author(s):  
Harald Rennhofer ◽  
Sven F. Plappert ◽  
Helga C. Lichtenegger ◽  
Sigrid Bernstorff ◽  
Michael Fitzka ◽  
...  
Keyword(s):  
Small Angle ◽  
Compressive Strain ◽  
Cellulose Ii ◽  
Stress Strain ◽  
X Ray ◽  
X Ray Scattering ◽  
Insight Into ◽  
Ray Scattering

In this article we report on the nanostructural changes of a cellulose II aerogel network during compressive strain of up to 80%, which are investigated by in situ small angle X-ray scattering and linked to the corresponding stress–strain curves.

In-Situ Study of Dynamic Structural Rearrangements During Stress Relaxation

1994 ◽  
Vol 38 ◽  
pp. 243-254 ◽  
Author(s):  
A. D. Westwood ◽  
C. E. Murray ◽  
I. C. Noyan
Keyword(s):  
Stress Relaxation ◽  
Structural Changes ◽  
Applied Strain ◽  
Homogeneous Distribution ◽  
Structural Rearrangements ◽  
X Ray Diffraction ◽  
X Ray ◽  
In Situ Study ◽  
Elastic Strains

Abstract We have conducted in-situ, real-time x-ray diffraction experiments to probe the dynamic structural changes occurring in copper during loading and then on relaxation. The 331 KαI, KαII peaks were used to monitor the development of elastic strains during loading, and their response during relaxation. The peak width was studied to better understand the structural changes that occur during loading, and more importantly on relaxation, since it is these structural rearrangements that reduce the overall strain in the system and allow the stress to relax. The results revealed that the structure is highly mobile immediately following the start of stress relaxation. The mobility decreases with time, scales with the magnitude of the applied strain and is highly dependent upon the applied strain rate. In addition, it was apparent that the KαI and KαII peaks do not respond in the same way to the elastic strains and that they also show different structural rearrangements. This suggests an in homogeneous distribution of displacements within the sample.

scholarly journals X-ray Diffraction Studies of Martensitic Transformations in Situ of the Pa-rameters of a Thin Crystalline Structure in TiNi Under External Loading

2017 ◽  
Vol 2 (1) ◽  
pp. 149
Author(s):  
A.A. Klopotov ◽  
A.I. Potekaev ◽  
E.S. Marchenko ◽  
O.M. Loskutov ◽  
G.A. Baygonakova ◽  
...  
Keyword(s):  
Applied Stress ◽  
Titanium Nickelide ◽  
Martensitic Transformations ◽  
Simultaneous Action ◽  
External Loading ◽  
Structure Parameters ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Dependences

The paper presents the results of the X-ray diffraction study of martensitic transformations B2-R-B19' in a wide temperature range under the simultaneous action of the applied stress in the alloy based on titanium nickelide. Temperature dependences of the crystal structure parameters in phases B2, R, B19' in samples under the action of the external applied stress have been determined. It has been found that heating of a TiNi-based alloy under loading leads to a rapprochement of atomic volumes of coexisting martensitic and austenitic phases.

Interpretation of Diffraction Data from In Situ Stress Measurements during Biaxial Sheet Metal Forming

2013 ◽  
Vol 768-769 ◽  
pp. 441-448
Author(s):  
Thomas Gnäupel-Herold ◽  
Mark Iadicola ◽  
Adam Creuziger ◽  
Tim Foecke ◽  
Lin Hu
Keyword(s):  
Sheet Metal Forming ◽  
Metal Forming ◽  
Lattice Strain ◽  
Hybrid Approach ◽  
Yield Behavior ◽  
Strain Measurements ◽  
X Ray ◽  
Lattice Strains ◽  
Model Predictions

Biaxial yield behavior is determined in-situ through X-ray lattice strain measurements. The distributions of d-spacings in different sample directions is affected both by the changes in diffraction elastic constants (DEC) from evolving texture and by the intergranular (IG) strains. Model predictions were found to be lacking, thus, a hybrid approach was developed based on measurements of DEC and IG strains at selected biaxial deformations. In order to convert measured lattice strains to stress for any given biaxial plastic strain a theoretical approximation was fitted to the experimental data, thus allowing the estimation of the evolution of DEC and IG strains with plastic deformation.

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