scholarly journals Stress Analysis by Kossel Microdiffraction on a Nickel-Based Single Crystal Superalloy during an In Situ Tensile Test – Comparison with Classical X-Ray Diffraction

2011 ◽  
Vol 681 ◽  
pp. 1-6 ◽  
Author(s):  
Denis Bouscaud ◽  
Raphaël Pesci ◽  
Sophie Berveiller ◽  
Etienne Patoor
Keyword(s):  
Crystallographic Orientation ◽  
Elastic Strain ◽  
Strain Tensor ◽  
Ccd Camera ◽  
X Ray Diffraction ◽  
Charge Coupled Device ◽  
X Ray ◽  
Set Up ◽  
Elastic Strain Tensor

A Kossel microdiffraction experimental set up is under development inside a Scanning Electron Microscope (SEM) in order to determine the crystallographic orientation as well as the inter- and intragranular strains and stresses. An area of about one cubic micrometer can be analysed using the microscope probe, which enables to study different kinds of elements such as a grain boundary, a crack, a microelectronic component, etc. The diffraction pattern is recorded by a high resolution Charge-Coupled Device (CCD) camera. The crystallographic orientation, the lattice parameters and the elastic strain tensor of the probed area are deduced from the pattern indexation using a homemade software. The purpose of this paper is to report some results achieved up to now to estimate the reliability of the Kossel microdiffraction technique.

scholarly journals Elastic strain tensor of zirconium hydrides in Zr2.5%Nb pressure tubes by synchrotron X-ray diffraction

2019 ◽  
Vol 52 (5) ◽  
pp. 1128-1143 ◽  
Author(s):  
Miguel Angel Vicente Alvarez ◽  
Javier Santisteban ◽  
Gladys Domizzi ◽  
John Okasinski ◽  
Jonathan Almer
Keyword(s):  
Phase Transformation ◽  
Elastic Strain ◽  
Power Plants ◽  
Strain Tensor ◽  
Axial Direction ◽  
Zirconium Hydride ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pole Figures ◽  
Elastic Strain Tensor

Zirconium alloys are used in fuel cladding and structural components of nuclear power plants. Hydrogen enters the Zr matrix during plant operation and precipitates as hydride particles that degrade the mechanical properties of the alloy, limiting service life. Knowledge of the stress state within hydride precipitates is important to understand stress-induced degradation mechanisms such as delayed hydride cracking, but no direct quantification has yet been reported in the literature. Here, measurements are reported of the average elastic strain tensor within δ zirconium hydride precipitates in Zr2.5%Nb pressure tube material from CANDU power plants. Complete intensity and strain pole figures for the hydride were obtained by synchrotron X-ray diffraction experiments on specimens with hydrogen contents ranging from ∼100 wt p.p.m. hydrogen to nearly 100% δ-hydride. Zirconium hydride precipitates by a process involving a martensitic transformation, with two hydride variants possible from a single α-Zr grain. A synthetic model of the hydride crystallographic texture allowed the interpretation of the measured strain pole figures and quantification of the elastic strain tensor for both texture components. It was found that the two variants appear in nearly equal proportion but with different stress states, differing in the sign of the shear strain components (∼±3000 µ∊). This difference is possibly associated with the shear movement of Zr atoms during the phase transformation. This suggests that hydride clusters are composed of stacks of smaller hydrides in alternating hydride variants. Stresses were estimated from a set of rather uncertain hydride elastic constants. Overall, both variants showed compressive strains along the tube axial direction (∼5000 µ∊). For low hydrogen concentrations, the hydrides' stress tensor is dominated by compressive stresses of ∼300 MPa along the axial direction, probably caused by the elongated morphology of hydride clusters along this direction, and variant-dependent shear stresses of ∼±100 MPa, probably from the shear movement of the Zr atoms involved in the phase transformation.

Submicrometre-resolution polychromatic three-dimensional X-ray microscopy

2012 ◽  
Vol 46 (1) ◽  
pp. 153-164 ◽  
Author(s):  
B. C. Larson ◽  
L. E. Levine
Keyword(s):  
Spatial Resolution ◽  
Elastic Strain ◽  
Strain Tensor ◽  
Three Dimensional ◽  
Direct Determination ◽  
Phase Identification ◽  
Sn Whisker ◽  
X Ray ◽  
Elastic Strain Tensor

The ability to study the structure, microstructure and evolution of materials with increasing spatial resolution is fundamental to achieving a full understanding of the underlying science of materials. Polychromatic three-dimensional X-ray microscopy (3DXM) is a recently developed nondestructive diffraction technique that enables crystallographic phase identification, determination of local crystal orientations, grain morphologies, grain interface types and orientations, and in favorable cases direct determination of the deviatoric elastic strain tensor with submicrometre spatial resolution in all three dimensions. With the added capability of an energy-scanning incident beam monochromator, the determination of absolute lattice parameters is enabled, allowing specification of the complete elastic strain tensor with three-dimensional spatial resolution. The methods associated with 3DXM are described and key applications of 3DXM are discussed, including studies of deformation in single-crystal and polycrystalline metals and semiconductors, indentation deformation, thermal grain growth in polycrystalline aluminium, the metal–insulator transition in nanoplatelet VO2, interface strengths in metal–matrix composites, high-pressure science, Sn whisker growth, and electromigration processes. Finally, the outlook for future developments associated with this technique is described.

Kinetics of high-pressure mineral phase transformations using in situ time-resolved X-ray diffraction in the Paris-Edinburgh cell: a practical guide for data acquisition and treatment

2008 ◽  
Vol 72 (2) ◽  
pp. 683-695 ◽  
Author(s):  
J. P. Perrillat
Keyword(s):  
High Pressure ◽  
Phase Transformations ◽  
Kinetic Studies ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Practical Guide ◽  
Set Up ◽  
Isothermal Kinetic

AbstractSynchrotron X-ray diffraction (XRD) is a powerful technique to study in situ and in real-time the structural and kinetic processes of pressure-induced phase transformations. This paper presents the experimental set-up developed at beamline ID27 of the ESRF to perform time-resolved angle dispersive XRD in the Paris-Edinburgh cell. It provides a practical guide for the acquisition of isobaric-isothermal kinetic data and the construction of transformation-time plots. The interpretation of experimental data in terms of reaction mechanisms and transformation rates is supported by an overview of the kinetic theory of solid-solid transformations, with each step of data processing illustrated by experimental results of relevance to the geosciences. Reaction kinetics may be affected by several factors such as the sample microstructure, impurities or differential stress. Further high-pressure kinetic studies should investigate the influence of such processes, in order to acquire kinetic information more akin to natural or technological processes.

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.

scholarly journals Single-shot full strain tensor determination with microbeam X-ray Laue diffraction and a two-dimensional energy-dispersive detector

2017 ◽  
Vol 50 (3) ◽  
pp. 901-908 ◽  
Author(s):  
A. Abboud ◽  
C. Kirchlechner ◽  
J. Keckes ◽  
T. Conka Nurdan ◽  
S. Send ◽  
...  
Keyword(s):  
Elastic Strain ◽  
Strain Tensor ◽  
Energy Dispersive ◽  
Single Shot ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Laue Diffraction ◽  
Experimental Procedure ◽  
X Ray ◽  
Diffraction Patterns

The full strain and stress tensor determination in a triaxially stressed single crystal using X-ray diffraction requires a series of lattice spacing measurements at different crystal orientations. This can be achieved using a tunable X-ray source. This article reports on a novel experimental procedure for single-shot full strain tensor determination using polychromatic synchrotron radiation with an energy range from 5 to 23 keV. Microbeam X-ray Laue diffraction patterns were collected from a copper micro-bending beam along the central axis (centroid of the cross section). Taking advantage of a two-dimensional energy-dispersive X-ray detector (pnCCD), the position and energy of the collected Laue spots were measured for multiple positions on the sample, allowing the measurement of variations in the local microstructure. At the same time, both the deviatoric and hydrostatic components of the elastic strain and stress tensors were calculated.

Micro X-ray diffraction (µXRD): a versatile technique for characterization of Earth and planetary materials

2007 ◽  
Vol 44 (9) ◽  
pp. 1333-1346 ◽  
Author(s):  
Roberta L Flemming
Keyword(s):  
Ccd Camera ◽  
Optical Microscope ◽  
X Ray Diffraction ◽  
Thin Sections ◽  
X Ray ◽  
Area Detector ◽  
Wide Range ◽  
Individual Grains ◽  
Planetary Materials

Recent developments in laboratory-based micro X-ray diffraction (µXRD) have extended X-ray examination of geomaterials to the microscopic level (50–500 µm), greatly expanding the applicability of XRD to mineralogy, petrology, materials, environmental, and planetary sciences. Laboratory-based µXRD has been accomplished using a Bruker™ D8 Discover diffractometer, having a sealed-tube Cu source, theta–theta geometry, Gobel mirror parallel optics with 50–500 µm collimation, and general area detector diffraction system (GADDS). A wide range of samples, including polished thin sections, electron probe microanalysis (EPMA) mounts, rock slabs, whole rocks, and powders have been examined with µXRD using a remote-controlled XYZ sample stage, with imaging by optical microscope monitor and charge-coupled device (CCD) camera. Individual grains in heterogeneous samples have been examined in situ, with little or no sample preparation. The two-dimensional GADDS preserves textural and crystallinity information (e.g., bioapatite) and easily discriminates between multiple phases of utility for synthetic or natural samples (e.g., mine tailings). In situ µXRD of minerals preserves spatial relationships, enabling study of orientational phenomena, such as strain-related mosaicity (giving “streaked” diffraction lines). Examples include strained quartz (La Malbaie quartzite, Quebec) and shocked clinopyroxenes (Shergottite NWA 3171). Mineral mapping has been demonstrated by reproducing exsolution textures of kamacite from taenite (Widmanstätten pattern) in the Toluca iron meteorite. Diffraction data obtained from single crystals (by the omega scan method) have enabled grain-by-grain correlation between unit cell (µXRD) and chemical composition (EPMA), as demonstrated by kimberlite indicator garnets. The examples shown herein demonstrate the breadth of information that can be obtained by µXRD of Earth and planetary materials.

In situ time-lapse synchrotron radiation X-ray diffraction of silver corrosion

2015 ◽  
Vol 30 (3) ◽  
pp. 694-701 ◽  
Author(s):  
Rita Wiesinger ◽  
Rosie Grayburn ◽  
Mark Dowsett ◽  
Pieter-Jan Sabbe ◽  
Paul Thompson ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Gas Flow ◽  
Time Lapse ◽  
X Ray Diffraction ◽  
X Ray ◽  
Environmental Cell ◽  
Temperature And Pressure ◽  
Set Up ◽  
Gaseous Corrosion

In order to study the initial corrosion processes of silver in the presence of corrosive gases in situ time-lapse XRD experiments were performed. The data collected using a newly combined environmental cell/gas flow set up introduces a set of highly useful tools for scientists to study time-lapse gaseous corrosion at ambient temperature and pressure.

In Situ X-RAY Diffraction Studies of Li+ Insertion into V6O13

1992 ◽  
Vol 293 ◽  
Author(s):  
C. Lampe-Önnerud ◽  
T. Gustafsson ◽  
J.O. Thomas
Keyword(s):  
Structural Changes ◽  
Open Circuit ◽  
Line Broadening ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gradual Loss ◽  
Set Up ◽  
Insertion Process ◽  
Reflection Intensity

AbstractA fast in situ X-ray powder diffraction set-up working in transmission mode is used to explore the structural changes occurring on Li+ insertion into the active V6O13 component of the cathode in a thin-film < Li I polymer electrolyte | V6O13 > battery. It is confirmed that the V6O13 is indeed converted reversibly into three discrete phases, LixV6O13 for x = 1, 4 and 8, as the fully charged cell (ca. 3.OV) is discharged to 1.8V. The effect on the insertion process of repeated cycling with different currents has been studied. Cell collapse was induced after ca. 35 cycles for 0.2 mA/cm2. This was not reflected, however, in any significant change in the diffraction pattern from the battery. Moreover, the battery returned to normal functioning after lying on open circuit for 7 days. A gradual loss of reflection intensity is observed, but no particle line-broadening. The implications of these results are discussed as they relate to the nature of the solid-state insertion process of Li+ into V6O13.

In Situ Observation of Polytype Switches during SiC PVT Bulk Growth by High Energy X-Ray Diffraction

2009 ◽  
Vol 615-617 ◽  
pp. 23-26 ◽  
Author(s):  
Peter J. Wellmann ◽  
Katja Konias ◽  
Philip Hens ◽  
Rainer Hock ◽  
Andreas Magerl
Keyword(s):  
Signal To Noise Ratio ◽  
High Energy ◽  
In Situ Observation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bulk Growth ◽  
Diffraction Patterns ◽  
Set Up ◽  
Good Signal

This work reports on the in-situ observation of a polytype switch during physical vapor transport (PVT) growth of bulk SiC crystals by x-ray diffraction. A standard PVT reactor for 2” and 3” bulk growth was set up in a high-energy x-ray diffraction lab. Due to the high penetration depth of the high-energy x-ray beam no modification of the PVT reactor was necessary in order to measure Laue diffraction patterns of the growing crystal with good signal to noise ratio. We report for the first time upon the in-situ observation of polytype switching during SiC bulk PVT growth.

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