In Situ X-Ray Diffraction of an Arc Weld Showing the Phase Transformations of Ti and Fe as a Function of Position in the Weld Performed at a Synchrotron

1993 ◽  
Vol 37 ◽  
pp. 479-482 ◽  
Author(s):  
Joe Wong ◽  
J. W. Elmer ◽  
P. A. Waide ◽  
E. M. Larson
Keyword(s):  
Combustion Synthesis ◽  
Ferroelectric Material ◽  
Bragg Diffraction ◽  
Intermediate Species ◽  
X Ray Diffraction ◽  
Synchrotron Source ◽  
X Ray ◽  
Subsequent Phase ◽  
Diffraction Peaks

The synchrotron x-ray source provides a unique opportunity to observe many “in-situ” processes. The formation of the “short-lived” intermediate species, Ta2C, during the combustion synthesis of TaC, has been observed and reported by monitoring the Bragg diffraction peaks of the reactants and products, Similarly, the synthesis of the ferroelectric material, BaTiO3, and subsequent phase transfonnation from cubic to tetragonal have also been investigated. These experiments would not have been possible without the high incident x-ray flux available at a synchrotron source.

The combustion synthesis of the ferroelectric material, BaTiO3, studied by time-resolved X-ray diffraction

1999 ◽  
Vol 14 (2) ◽  
pp. 111-113 ◽  
Author(s):  
E. M. Larson ◽  
Joe Wong ◽  
J. B. Holt ◽  
P. A. Waide ◽  
B. Rupp
Keyword(s):  
Combustion Synthesis ◽  
Ferroelectric Material ◽  
Bragg Diffraction ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Tetragonal Form ◽  
Diffraction Peaks ◽  
The Common

The combustion synthesis of the common ferroelectric material, BaTiO3, was developed using the stoichiometry: BaO2+0.2 Ti+0.8 TiO2→BaTiO3+0.3 O2. An adiabatic temperature, Tad, of the reaction was calculated from known thermodynamic data to be 1917 °C. Real time chemical changes in the formation of BaTiO3 during the reaction have been monitored using time-resolved X-ray diffraction with synchrotron radiation as the X-ray source. A time resolution of 250 ms was achieved. The combustion synthesis of BaTiO3 was followed by observing the intensities of reactant and product Bragg diffraction peaks in order to qualitatively identify the phases present. Because BaTiO3 forms initially as a cubic phase, X-ray diffraction of the product was monitored for a period of 20 min after the reaction to observe the phase transformation to the tetragonal form. This transformation is evident in these post-reaction scans as the cubic 110 and 220 peaks are split to the tetragonal 101/110 and 202/220 ones, respectively.

Size Effects in Plasticity: Experiments and Simulations

2006 ◽  
Vol 503-504 ◽  
pp. 193-200 ◽  
Author(s):  
Helena Van Swygenhoven
Keyword(s):  
Large Scale ◽  
Tensile Deformation ◽  
Profile Analysis ◽  
Bragg Diffraction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Peaks ◽  
New Applications ◽  
Source And Sink

Large scale computer simulations suggest that in nanocrystalline metals grain boundaries act as source and sink for dislocations. This suggestion has been the motivation for developing a new in-situ X-ray diffraction technique that allow peak profile analysis of several Bragg diffraction peaks during tensile deformation. Synergies between simulations and experiments are discussed including new applications of the in-situ technique.

scholarly journals In Situ Stress Tensor Determination during Phase Transformation of a Metal Matrix Composite by High-Energy X-ray Diffraction

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1415 ◽  
Author(s):  
Guillaume Geandier ◽  
Lilian Vautrot ◽  
Benoît Denand ◽  
Sabine Denis
Keyword(s):  
Phase Transformation ◽  
Stress Tensor ◽  
Metal Matrix Composite ◽  
Matrix Composite ◽  
Metal Matrix ◽  
High Energy ◽  
X Ray Diffraction ◽  
Synchrotron Source ◽  
X Ray

In situ high-energy X-ray diffraction using a synchrotron source performed on a steel metal matrix composite reinforced by TiC allows the evolutions of internal stresses during cooling to be followed thanks to the development of a new original experimental device (a transportable radiation furnace with controlled rotation of the specimen). Using the device on a high-energy beamline during in situ thermal treatment, we were able to extract the evolution of the stress tensor components in all phases: austenite, TiC, and even during the martensitic phase transformation of the matrix.

A time-resolved diffraction study of the Ta–C solid combustion system

1993 ◽  
Vol 8 (7) ◽  
pp. 1533-1541 ◽  
Author(s):  
E.M. Larson ◽  
Joe Wong ◽  
J.B. Holt ◽  
P.A. Waide ◽  
G. Nutt ◽  
...  
Keyword(s):  
Combustion Synthesis ◽  
Carbon Diffusion ◽  
Time Frame ◽  
Combustion System ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Reaction Proceeds ◽  
Diffraction Peaks ◽  
Product Powder

The formation of TaC and Ta2C by combustion synthesis from their elemental constituents has been studied by time-resolved x-ray diffraction (TRXRD) using synchrotron radiation. The reactions have been followed with a time resolution down to 50 ms. Since the adiabatic temperatures for both reactions are well below any liquidus temperature in the Ta—C phase diagram, no melting occurs and these combustion reactions occur purely in the solid state. The phase transformations associated with these reactions are followed by monitoring the disappearance of reactant and appearance of product powder diffraction peaks in real time as the reaction front propagates through the combusting specimen. In the synthesis of TaC, the results show the formation of the subcarbide (Ta2C phase as an intermediate. In the synthesis of Ta2C, the reaction proceeds directly to the product with no discernible intermediate Ta–C phase within a 50 ms time frame. The chemical dynamics associated with the combustion synthesis of TaC may be described by an initial phase transformation to hexagonal Ta2C arising from carbon diffusion into the Ta metal lattice. As more carbon is available this intermediate subcarbide phase, which has one-half of its octahedral interstices occupied by the carbon, further transforms to the cubic TaC final product, in which all octahedral sites are now occupied. The time-resolved data indicate that the rate of formation of Ta2C is a factor of two faster than that of TaC.

scholarly journals Superflexibility of graphene oxide

2016 ◽  
Vol 113 (40) ◽  
pp. 11088-11093 ◽  
Author(s):  
Philippe Poulin ◽  
Rouhollah Jalili ◽  
Wilfrid Neri ◽  
Frédéric Nallet ◽  
Thibaut Divoux ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Unique Feature ◽  
Bending Rigidity ◽  
X Ray Diffraction ◽  
Synchrotron Source ◽  
X Ray ◽  
Bending Modulus ◽  
Bendable Electronics ◽  
Very High

Graphene oxide (GO), the main precursor of graphene-based materials made by solution processing, is known to be very stiff. Indeed, it has a Young’s modulus comparable to steel, on the order of 300 GPa. Despite its very high stiffness, we show here that GO is superflexible. We quantitatively measure the GO bending rigidity by characterizing the flattening of thermal undulations in response to shear forces in solution. Characterizations are performed by the combination of synchrotron X-ray diffraction at small angles and in situ rheology (rheo-SAXS) experiments using the high X-ray flux of a synchrotron source. The bending modulus is found to be 1kT, which is about two orders of magnitude lower than the bending rigidity of neat graphene. This superflexibility compares with the fluidity of self-assembled liquid bilayers. This behavior is discussed by considering the mechanisms at play in bending and stretching deformations of atomic monolayers. The superflexibility of GO is a unique feature to develop bendable electronics after reduction, films, coatings, and fibers. This unique combination of properties of GO allows for flexibility in processing and fabrication coupled with a robustness in the fabricated structure.

RF-Magnetron Sputtered Strontium Titanate: Structure, Processing and Property Relationships

1999 ◽  
Vol 603 ◽  
Author(s):  
B.J. Gibbons ◽  
Y. Fan ◽  
A.T. Findikoglu ◽  
D.W. Reagor ◽  
Q.X. Jia
Keyword(s):  
Room Temperature ◽  
Low Frequency ◽  
Ozone Treatment ◽  
X Ray Diffraction ◽  
X Ray ◽  
Treated Sample ◽  
Diffraction Peaks ◽  
Compositional Variations ◽  
First Time

AbstractThe low frequency dielectric properties of epitaxial SrTiO3 thin films deposited on LaAlO3 are presented. The films were deposited using radio-frequency magnetron sputtering from stoichiometric targets in an Ar/O2 atmosphere. For the first time, the effects of in situ ozone annealing during the early stages of deposition were explored. X-ray diffraction results indicated that the ozone treatment resulted in more symmetric and sharper diffraction peaks (2 Θ- FWHM decreased from 0.17° to 0.10°). In addition, the peaks for the ozone treated samples were shifted in 2 Θ towards values approaching the bulk value. Rutherford backscattering measurements showed Sr/Ti ratios of 1:1 for these samples, indicating these peak shifts are not due to compositional variations. The dielectric constant of the ozone treated samples increased from 275 at room temperature to 1175 at 22 K (measured at 100 kHz). The effective loss tangent of the device remained between 1 × 10−4 and 1 × 10−3 down to 100 K, where it began to increase. The tunability was also measured. The ozone treated sample showed tunability of 46%, 43% and 38% at 22 K, 40 K and 60 K, respectively. Finally, similar measurements were completed at 1 MHz, indicating a minimal dependence of these properties on frequencies in this range.

Microstructure of In Situ Particles/7055Al Matrix Composites with Deep Cryogenic Treatment

2012 ◽  
Vol 217-219 ◽  
pp. 114-118 ◽  
Author(s):  
Xun Yin Zhang ◽  
Gui Rong Li ◽  
Ting Wang Zhang ◽  
Lei Cao ◽  
Hong Ming Wang ◽  
...  
Keyword(s):  
Volume Fraction ◽  
Cryogenic Treatment ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
Deep Cryogenic Treatment ◽  
X Ray ◽  
Diffraction Peaks

Al2O3，Al3Ti and Al3Zr particles reinforced 7055 aluminium matrix composites were fabricated via melt reaction method. The volume fraction is controlled at about 4-5%. After extrusion and solution-aging heat treatment the sample was prepared for deep cryogenic treatment, The microstructure and evolution of mechanical properties of (Al3Ti+Al3Zr)p/7055 composites were analyzed using optical microscopy(OM),scanning electronic microscopy(SEM) and X-ray diffraction(XRD). Some θ(Al2Cu) phases with nanometer size precipitate in the inner grain. As some grains preferred orient the intensity of some main diffraction peaks increase. Compared with those of as-cast and squeezed states the micro hardness has increased by 16.8% and 10.0% separately.

scholarly journals Lattice Strain Evolutions in Ni-W Alloys during a Tensile Test Combined with Synchrotron X-ray Diffraction

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4027
Author(s):  
Tarik Sadat ◽  
Damien Faurie ◽  
Dominique Thiaudière ◽  
Cristian Mocuta ◽  
David Tingaud ◽  
...  
Keyword(s):  
Solid Solution ◽  
Tensile Test ◽  
Single Phase ◽  
Lattice Strain ◽  
Tensile Tests ◽  
X Ray Diffraction ◽  
X Ray ◽  
Significant Difference ◽  
Diffraction Peaks

Ni and Ni(W) solid solution of bulk Ni and Ni-W alloys (Ni-10W, Ni-30W, and Ni-50W) (wt%) were mechanically compared through the evolution of their {111} X-ray diffraction peaks during in situ tensile tests on the DiffAbs beamline at the Synchrotron SOLEIL. A significant difference in terms of strain heterogeneities and lattice strain evolution occurred as the plastic activity increased. Such differences are attributed to the number of brittle W clusters and the hardening due to the solid solution compared to the single-phase bulk Ni sample.

scholarly journals Ultrafast visualization of crystallization and grain growth in shock-compressed SiO2

2015 ◽  
Vol 6 (1) ◽  
Author(s):  
A. E. Gleason ◽  
C. A. Bolme ◽  
H. J. Lee ◽  
B. Nagler ◽  
E. Galtier ◽  
...  
Keyword(s):  
High Pressure ◽  
Grain Growth ◽  
Shock Compression ◽  
Fused Silica ◽  
X Ray Diffraction ◽  
Pump Probe ◽  
X Ray ◽  
Equilibrium Processes ◽  
Diffraction Peaks

Abstract Pressure- and temperature-induced phase transitions have been studied for more than a century but very little is known about the non-equilibrium processes by which the atoms rearrange. Shock compression generates a nearly instantaneous propagating high-pressure/temperature condition while in situ X-ray diffraction (XRD) probes the time-dependent atomic arrangement. Here we present in situ pump–probe XRD measurements on shock-compressed fused silica, revealing an amorphous to crystalline high-pressure stishovite phase transition. Using the size broadening of the diffraction peaks, the growth of nanocrystalline stishovite grains is resolved on the nanosecond timescale just after shock compression. At applied pressures above 18 GPa the nuclueation of stishovite appears to be kinetically limited to 1.4±0.4 ns. The functional form of this grain growth suggests homogeneous nucleation and attachment as the growth mechanism. These are the first observations of crystalline grain growth in the shock front between low- and high-pressure states via XRD.

scholarly journals Study of Elastic Behavior of Metallic Thin Films by 2D Synchrotron XRD and in situ Tensile Testing

2007 ◽  
Vol 1027 ◽  
Author(s):  
Geandier Guillaume ◽  
Renault Pierre-Olivier ◽  
Goudeau Philippe ◽  
Eric Le Bourhis ◽  
Girault Baptiste
Keyword(s):  
Thin Films ◽  
Mechanical Response ◽  
Tensile Tests ◽  
Elastic Behavior ◽  
Metallic Thin Films ◽  
X Ray Diffraction ◽  
Synchrotron Source ◽  
X Ray ◽  
Transmission Geometry

AbstractUnderstanding the mechanical behaviour of nano-structured thin films in relation to their structure, in particular to the grain size, is of high importance for the development of technological applications. Model nanometric multilayer W/Au systems exhibiting different structures are elaborated. These films are supported by a (thin) polyimide substrate. Films mechanical response is characterized experimentally by tensile tests carried out in-situ in a X-ray diffractometer installed on a synchrotron source. X-ray diffraction in transmission geometry has been used to study the deformations of both phases as a function of applied load. This geometry has been developed in the aim of optimizing the experiment time.

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