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.

Study of Stresses in Texture Components Using Neutron Diffraction

2013 ◽  
Vol 768-769 ◽  
pp. 289-295
Author(s):  
Andrzej Baczmański ◽  
Elżbieta Gadalińska ◽  
Sebastian Wroński ◽  
Léa Le Joncour ◽  
Benoit Panicaud ◽  
...  
Keyword(s):  
Experimental Data ◽  
Neutron Diffraction ◽  
Tensile Load ◽  
Group Method ◽  
Model Calculations ◽  
Lattice Strains ◽  
Consistent Model ◽  
Self Consistent ◽  
Full Stress Tensor

In this work a new method for analysis of neutron diffraction results obtained during “in situ” tensile load is proposed and tested. The methodology is based on the measurements of lattice strains during “in situ” tensile test for several hkl reflections and for different orientations of the sample with respect to the scattering vector. As the result the full stress tensor for preferred texture orientations in function of applied stress can be determined with help of crystallite group method. The experimental data are presented and compared with self-consistent model calculations performed for groups of grains corresponding to the measured hkl reflections.

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.

Neutron Diffraction Study of Elastoplastic Behaviour of Al/SiCp Metal Matrix Composite

2017 ◽  
Vol 905 ◽  
pp. 66-73
Author(s):  
Elżbieta Gadalińska ◽  
Andrzej Baczmański ◽  
Sebastian Wroński ◽  
Mirosław Wróbel ◽  
Alain Lodini ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Metal Matrix Composite ◽  
Matrix Composite ◽  
Metal Matrix ◽  
Tensile Deformation ◽  
Neutron Radiation ◽  
Neutron Diffraction Study ◽  
Lattice Strains ◽  
Critical Resolved Shear Stress

The TOF neutron diffraction measurements were done for Al/SiCp metal–matrix composite (17% of SiC) subjected to T6 thermal treatment. Using three separated diffraction peaks of SiC phase and four peaks of Al phase, the lattice strains were measured for both phases independently during in situ tensile test. The experimental results were presented in comparison with elastoplastic model, which allows to find the values of parameters determining plastic deformation of Al matrix (critical resolved shear stress and hardening parameter). Additionally, the results of TOF method were compared with those which were obtained with monochromatic neutron radiation (LLB, Saclay). In the latter experiment Al/SiCp composite containing 25% of SiC was measured. It was shown that after elastoplastic deformation the mismatch stresses determined for both phases relax during tensile deformation.

Quantitative Estimation of the Second Order Plastic Incompatibility Stresses in Textured Duplex Steel

2006 ◽  
Vol 524-525 ◽  
pp. 841-846 ◽  
Author(s):  
Sebastian Wroński ◽  
Andrzej Baczmanski ◽  
Krzysztof Wierzbanowski ◽  
Chedly Braham ◽  
Rim Dakhlaoui ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Elastoplastic Deformation ◽  
Quantitative Estimation ◽  
Diffraction Method ◽  
Second Order ◽  
The Self ◽  
Two Phase ◽  
Duplex Steel ◽  
Consistent Model ◽  
Self Consistent

A new method for determining the parameters characterising elastoplastic deformation of two-phase material is proposed. The method is based on the results of neutron diffraction, which are analysed using the self-consistent rate-independent model of elastoplastic deformation. The neutron diffraction method (time-of-flight technique) was applied and the self-consistent model was used to predict the second order stresses in austeno-ferritic duplex steel. Calculations based on the model were successfully compared with experimental results for both phases of the duplex steel.

scholarly journals Investigation of α-Ti plastic anisotropy under thermomechanical loadings: temperature influence on deformation mechanisms

2020 ◽  
Vol 321 ◽  
pp. 07004
Author(s):  
K. E. Agbovi ◽  
J. Fajoui ◽  
B. Girault ◽  
D. Gloaguen ◽  
S. Kabra ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Bulk Material ◽  
Plastic Anisotropy ◽  
Diffraction Method ◽  
Tensile Tests ◽  
Deformation Mechanisms ◽  
Uniaxial Tensile ◽  
Lattice Strains ◽  
Deformation Modes

In situ neutron diffraction method has been used to investigate deformation mechanisms (slip and twinning deformation modes) during uniaxial tensile tests of extruded a-titanium alloy at room temperature, 100 and 300 °C. For this purpose, the prediction of an Elasto-Plastic Self-Consistent (EPSC) model was compared with the experimental data. Results show that there is a good agreement between the simulations and neutron diffraction measurements. The EPSC model enables realistic predictions of not only the elastic lattice strains developed in variously oriented grain families but also the macroscopic stress-strain response within the bulk material.

scholarly journals The Hardening in Alloys and Composites and Its Examination with a Diffraction and Self-Consistent Model

2018 ◽  
Vol 2018 (10) ◽  
pp. 31-46
Author(s):  
Elżbieta Gadalińska ◽  
Andrzej Baczmański ◽  
Sebastian Wroński ◽  
Mirosław Wróbel ◽  
Christian Scheffzük
Keyword(s):  
Tensile Test ◽  
Stress Measurement ◽  
Hardening Process ◽  
Consistent Model ◽  
Self Consistent ◽  
Hardening Parameter ◽  
Critical Resolved Shear Stress ◽  
The Impact

Abstract The paper presents the results of diffraction stress measurement in Al/SiC composite and in 2124T6 aluminum alloy during the in situ tensile test. The main aim of the work is to observe the stress values for different stages of tensile test for the composite after applying two types of thermal treatment and for the alloy used as a matrix in this composite, to identify the type of hardening process. The experimental results were compared against the calculations results obtained from the self-consistent model developed by Baczmański [1] - [3] to gain the information about the micromechanical properties (critical resolved shear stress τcr and hardening parameter H) of the examined materials. This comparison allowed researchers to determine the role of reinforcement in the composite as well as the impact of the heat treatment on the hardening of the material.

Evaluating the Mechanical Behavior of 316 Stainless Steel at the Microscale Using Finite Element Modelling and In-Situ Neutron Scattering

2010 ◽  
Author(s):  
Dong-Feng Li ◽  
Noel P. O’Dowd ◽  
Catrin M. Davies ◽  
Shu-Yan Zhang
Keyword(s):  
Finite Element ◽  
Stainless Steel ◽  
Finite Element Modelling ◽  
Mechanical Response ◽  
Fe Model ◽  
Lattice Strains ◽  
Crystallographic Slip ◽  
In Situ Neutron Diffraction ◽  
Elastic Lattice

In this study, the deformation behavior of an austenitic stainless steel is investigated at the microscale by means of in-situ neutron diffraction (ND) measurements in conjunction with finite-element (FE) simulations. Results are presented in terms of (elastic) lattice strains for selected grain (crystallite) families. The FE model is based on a crystallographic (slip system based) representation of the deformation at the microscale. The present study indicates that combined in-situ ND measurement and micromechanical modelling provides an enhanced understanding of the mechanical response at the microscale in engineering steels.

scholarly journals Bending Behavior of a Wrought Magnesium Alloy Investigated by the In Situ Pinhole Neutron Diffraction Method

Crystals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 348 ◽  
Author(s):  
Wei Wu ◽  
Alexandru Stoica ◽  
Dunji Yu ◽  
Matthew Frost ◽  
Harley Skorpenske ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Neutron Diffraction ◽  
Spatial Resolution ◽  
Diffraction Method ◽  
Middle Layer ◽  
Mapping Method ◽  
Step Size ◽  
Four Point Bending ◽  
Wrought Magnesium Alloy

The tensile twinning and detwinning behaviors of a wrought magnesium alloy have been investigated during in situ four-point bending using the state-of-the-art high spatial resolution pinhole neutron diffraction (PIND) method. The PIND method allowed us to resolve the tensile twinning/detwinning and lattice strain distributions across the bending sample during a loading-unloading sequence with a 0.5 mm step size. It was found that the extensive tensile twinning and detwinning occurred near the compression surface, while no tensile twinning behavior was observed in the middle layer and tension side of the bending sample. During the bending, the neutral plane shifted from the compression side to the tension side. Compared with the traditional neutron diffraction mapping method, the PIND method provides more detailed information inside the bending sample due to a higher spatial resolution.

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