Modeling the Influence of Strain Fields Around Precipitates on Defect Equilibria and Kinetics Under Irradiation in ODS Steels: A Multi Scale Approach

2019 ◽  
Author(s):  
Markus Mock ◽  
Peter Stein ◽  
Celine Hin ◽  
Karsten Albe
Keyword(s):  
Strain Fields ◽  
Multi Scale ◽  
Defect Equilibria ◽  
Ods Steels

scholarly journals Predicting point defect equilibria across oxide hetero-interfaces: model system of ZrO2/Cr2O3

2017 ◽  
Vol 19 (5) ◽  
pp. 3869-3883 ◽  
Author(s):  
Jing Yang ◽  
Mostafa Youssef ◽  
Bilge Yildiz
Keyword(s):  
Space Charge ◽  
Point Defect ◽  
Model System ◽  
Space Charge Layer ◽  
Scale Model ◽  
Charge Layer ◽  
Multi Scale ◽  
Defect Equilibria

We present a multi-scale model to predict defect redistribution both in interface core and space charge layer across oxide/oxide hetero-interfaces.

Multi-Scale Strain Measurements of a Particulate Composite Material

2002 ◽  
Author(s):  
C. T. Liu ◽  
C. W. Smith ◽  
G. Ravichandran
Keyword(s):  
Composite Material ◽  
Particulate Composite ◽  
Experimental Results ◽  
Strain Fields ◽  
Length Scales ◽  
Strain Measurements ◽  
Multi Scale ◽  
Hard Particles ◽  
Particulate Composite Material

In this study, the strain fields on two different length scales in a particulate composite material containing hard particles embedded in a rubbery matrix were investigated, using two different techniques. The experimental results were analyzed and are discussed.

scholarly journals 3D Strain Mapping of Opaque Materials Using an Improved Digital Volumetric Speckle Photography Technique with X-Ray Microtomography

2019 ◽  
Vol 9 (7) ◽  
pp. 1418 ◽  
Author(s):  
Lingtao Mao ◽  
Haizhou Liu ◽  
Ying Zhu ◽  
Ziyan Zhu ◽  
Rui Guo ◽  
...  
Keyword(s):  
Composite Beam ◽  
Speckle Photography ◽  
Woven Composite ◽  
Strain Mapping ◽  
Strain Fields ◽  
X Ray ◽  
Red Sandstone ◽  
Three Point Bending ◽  
Multi Scale ◽  
Calculation Process

Digital volumetric speckle photography (DVSP) method has been used to strain investigation in opaque materials. In this paper, an improved DVSP algorithm is introduced, in which a multi-scale coarse–fine subset calculation process and a subvoxel shifting technique are applied to increase accuracy. We refer to the new algorithm as Multi-scale and Subvoxel shifting Digital Volumetric Speckle Photography (MS-DVSP). The displacement and strain fields of a red sandstone cylinder exposed to uniaxial compression and a woven composite beam under three-point bending are mapped in detail. The characteristics of the interior deformation of the specimens are clearly depicted, thus elucidating the failure mechanism of the materials.

Characteristic Geometry and Diffraction Contrast of Dispersed ThO2 Crystals

1969 ◽  
Vol 27 ◽  
pp. 168-169
Author(s):  
R. J. Horylev ◽  
L. E. Murr
Keyword(s):  
Dark Field ◽  
Particle Orientation ◽  
Contrast Effects ◽  
Strain Fields ◽  
Diffraction Contrast ◽  
Dispersed Particles ◽  
Field Electron Microscopy ◽  
Dark Field Electron ◽  
Particle Images ◽  
Diffraction Effects

Smith has shown by dark-field electron microscopy of extracted ThO2 particles from TD-nickel (2% ThO2) that they possess single crystal characteristics. It is generally assumed that these particle dispersions are incoherent. However, some diffraction effects associated with the particle images appeared to be similar to coherency strain fields. The present work will demonstrate conclusively that ThO2 dispersed particles in TD-nickel (2% ThO2) and TD-NiCr (2% ThO2, 20% Cr, Ni) are single crystals. Moreover, the diffraction contrast effects are extinction fringes. That is, these effects arise because of the particle orientation with respect to the electron beam and the extinction conditions for various operating reflections The particles are in fact incoherent.

Effect of strain on ADF-STEM high-resolution images

1991 ◽  
Vol 49 ◽  
pp. 666-667
Author(s):  
M. Kelly ◽  
D.M. Bird
Keyword(s):  
High Resolution ◽  
Strong Influence ◽  
Intensity Variation ◽  
Dark Field ◽  
Atomic Resolution ◽  
Strain Fields ◽  
High Resolution Image ◽  
Annular Dark Field ◽  
High Resolution Images ◽  
Interesting Alternative

It is well known that strain fields can have a strong influence on the details of HREM images. This, for example, can cause problems in the analysis of edge-on interfaces between lattice mismatched materials. An interesting alternative to conventional HREM imaging has recently been advanced by Pennycook and co-workers where the intensity variation in the annular dark field (ADF) detector is monitored as a STEM probe is scanned across the specimen. It is believed that the observed atomic-resolution contrast is correlated with the intensity of the STEM probe at the atomic sites and the way in which this varies as the probe moves from cell to cell. As well as providing a directly interpretable high-resolution image, there are reasons for believing that ADF-STEM images may be less suseptible to strain than conventional HREM. This is because HREM images arise from the interference of several diffracted beams, each of which is governed by all the excited Bloch waves in the crystal.

Analysis of 2D and 3D defects associated with precipitation of Cu in silicon

1991 ◽  
Vol 49 ◽  
pp. 870-871
Author(s):  
P.M. Rice ◽  
MJ. Kim ◽  
R.W. Carpenter
Keyword(s):  
Colony Growth ◽  
Dark Field ◽  
Dark Side ◽  
Silicide Phase ◽  
Strain Fields ◽  
Near Surface ◽  
Unknown Composition ◽  
Secondary Precipitates ◽  
20 Nm ◽  
2D And 3D

Extrinsic gettering of Cu on near-surface dislocations in Si has been the topic of recent investigation. It was shown that the Cu precipitated hetergeneously on dislocations as Cu silicide along with voids, and also with a secondary planar precipitate of unknown composition. Here we report the results of investigations of the sense of the strain fields about the large (~100 nm) silicide precipitates, and further analysis of the small (~10-20 nm) planar precipitates.Numerous dark field images were analyzed in accordance with Ashby and Brown's criteria for determining the sense of the strain fields about precipitates. While the situation is complicated by the presence of dislocations and secondary precipitates, micrographs like those shown in Fig. 1(a) and 1(b) tend to show anomalously wide strain fields with the dark side on the side of negative g, indicating the strain fields about the silicide precipitates are vacancy in nature. This is in conflict with information reported on the η'' phase (the Cu silicide phase presumed to precipitate within the bulk) whose interstitial strain field is considered responsible for the interstitial Si atoms which cause the bounding dislocation to expand during star colony growth.

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