scholarly journals Accounting for a Distribution of Morphologies and Orientations on Stresses Analysis by X-Ray and Neutron Diffraction: Normalized Self-Consistent Modeling

2014 ◽  
Vol 996 ◽  
pp. 82-87
Author(s):  
Viwanou Hounkpati ◽  
Sylvain Fréour ◽  
David Gloaguen ◽  
Vincent Legrand
Keyword(s):  
Neutron Diffraction ◽  
Crystallographic Texture ◽  
X Ray ◽  
Consistent Model ◽  
Self Consistent

The historical Eshelby-Kröner self-consistent model is only valid in the case when grains can be assumed similar to ellipsoids aligned preferentially along a same direction into the polycrystal. In this work, distributions of crystallites morphologies and geometrical orientations were accounted for, owing to the so-called generalized self-consistent model, in order to satisfy Hills averages principles. Different nonlinear εφψ-vs.-sin2ψ distributions were predicted in elasticity, even in the absence of crystallographic texture, in the case when several morphologies and geometrical orientations coexist within the same polycrystal.

scholarly journals Stellar Flares: Observations and Theory

1989 ◽  
Vol 104 (2) ◽  
pp. 49-52
Author(s):  
Suzanne L. Hawley
Keyword(s):  
Scaling Law ◽  
Dynamic Scaling ◽  
X Ray ◽  
Temperature Distributions ◽  
Photometric And Spectroscopic Observations ◽  
Stellar Flares ◽  
Consistent Model ◽  
Self Consistent ◽  
Flare Model ◽  
Large Flare

AbstractPhotometric and spectroscopic observations of a very large flare on AD Leo are presented. A self consistent model of a flare corona, transition region and chromosphere is developed; in particular the chromospheric temperature distributions resulting from X-ray and EUV irradiation by coronae of various temperatures are determined. The predicted line fluxes in Hγ are compared to the observed line fluxes to find the coronal temperature as a function of time during the flare. This run of temperature with time is then compared with the predictions of an independent theoretical flare model based on a dynamic scaling law (see paper by Fisher and Hawley, these proceedings).

Localization of Stresses in Polycrystalline Grains Measured by Neutron Diffraction and Predicted by Self-Consistent Model

2011 ◽  
Vol 681 ◽  
pp. 103-108
Author(s):  
Anita Gaj ◽  
Lea le Joncour ◽  
Andrzej Baczmanski ◽  
Sebastian Wroński ◽  
Benoit Panicaud ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Load Transfer ◽  
Diffraction Method ◽  
Lattice Strains ◽  
Consistent Model ◽  
Self Consistent ◽  
Main Component ◽  
Critical Resolved Shear Stress ◽  
Elastic Lattice

Time of flight neutron diffraction method was applied to measure elastic lattice strains in austenitic steel during "in situ" tensile test. Comparing experimental data with self-consistent model, the critical resolved shear stress and hardening parameters were determined for polycrystalline grains. The result allowed us to determine the main component of the stress localization tensor, relating the rate of grain stress with the applied macrostress rate. The evolution of concentration tensor in function of the applied macrostress was analyzed. Finally, the load transfer between grains during yielding of the sample was studied.

scholarly journals Determining Ti-17 β-Phase Single-Crystal Elasticity Constants through X-Ray Diffraction and Inverse Scale Transition Model

2011 ◽  
Vol 681 ◽  
pp. 97-102 ◽  
Author(s):  
Sylvain Fréour ◽  
Emmanuel Lacoste ◽  
Manuel François ◽  
Ronald Guillén
Keyword(s):  
Mechanical Load ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Β Phase ◽  
Consistent Model ◽  
Self Consistent ◽  
Diffraction Lattice ◽  
Two Phases ◽  
Multi Phase

The scope of this work is the determination of single-crystals elastic constants (SEC) from X-ray diffraction lattice strains measurements performed on multi-phase polycrystals submitted to mechanical load through a bending device. An explicit three scales inverse self-consistent model is developed in order to express the SEC of a cubic phase, embedded in a multi-phase polycrystal, as a function of its X-ray Elasticity Constants. Finally, it is applied to a two-phases (α+β) titanium based alloy (Ti-17), in order to estimate Ti-17 β-phase unknown SEC. The purpose of the present work is to account the proper microstructure of the material. In particular, the morphologic texture of Ti-17 a-phase, i.e. the relative disorientation of the needle-shaped grains constituting this phase, is considered owing to the so-called Generalized Self-Consistent model.

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.

A self-consistent model for line trapping effect in x-ray lasers

1995 ◽  
Author(s):  
Djamel E. Benredjem ◽  
Alain Sureau ◽  
Clary Möller ◽  
Hélène Guennou
Keyword(s):  
X Ray ◽  
Trapping Effect ◽  
Consistent Model ◽  
Self Consistent

Microstresses Determined by Neutron Diffraction and Self-consistent Model

2006 ◽  
pp. 477-486
Author(s):  
A. Baczmanski ◽  
C. Braham ◽  
R. Levy-Tubiana ◽  
A. Lodini ◽  
K. Wierzbanowski
Keyword(s):  
Neutron Diffraction ◽  
Consistent Model ◽  
Self Consistent

scholarly journals Effect of Interlamellar Spacing on the Monotonic Behavior of C70 Pearlitic Steel

2014 ◽  
Vol 996 ◽  
pp. 88-93
Author(s):  
Houda Yahyaoui ◽  
Habib Sidhom ◽  
Chedly Braham ◽  
Andrzej Baczmański ◽  
Manuel François ◽  
...  
Keyword(s):  
Plastic Anisotropy ◽  
Critical Shear Stress ◽  
Interlamellar Spacing ◽  
Pearlitic Steel ◽  
Shear Stresses ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lattice Strains ◽  
Consistent Model ◽  
Self Consistent

The effect of interlamellar spacing on monotonic behavior of C70 pearlitic steel was investigated. Tensile tests under X-ray diffraction coupled with self-consistent model have been used to identify the role of interlamellar spacing on the ferrite plasticity parameters and residual stresses. It has been established that yielding of pearlite is controlled by ferrite critical shear stresses ( τc 0α) which is higher for the smaller interlamellar spacing. Moreover, the residual stress level in ferrite is higher for the largest interlamellar spacing under the same imposed total strain. Lattice strains, measured by synchrotron X-ray diffraction, show an elastic and plastic anisotropy of ferrite crystallites and high stresses in cementite which confirm the self-consistent model calculation. Keywords: Pearlitic steel, X-ray diffraction, Synchrotron radiation, Self-consistent model, Critical shear stress, Lattice strains.

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