scholarly journals Understanding Thermodynamic and Kinetic Stabilization of FeNiZr via Systematic High-Throughput In Situ XRD Analysis

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 482
Author(s):  
Efraín Hernández-Rivera ◽  
Sean J. Fudger ◽  
B. Chad Hornbuckle ◽  
Anthony J. Roberts ◽  
Kristopher A. Darling
Keyword(s):  
Statistical Approach ◽  
Xrd Analysis ◽  
Quantitative Information ◽  
Transfer Model ◽  
In Situ Xrd ◽  
Flow Through ◽  
Xrd Patterns ◽  
Powder Compacts

The role of kinetically and thermodynamically driven microstructural evolution on FeNiZr was explored through in situ XRD analysis. A statistical approach based on log-likelihoods and composite link model was used to fit and extract important data from the XRD patterns. Best practices on using the statistical approach to obtained quantitative information from the XRD patterns was presented. It was shown that the alloyed powder used in the current study presents more thermodynamic stability than previously reported ball-milled powders. Based on hardness values, it was shown that mechanical strength is expected to be retained at higher processing temperatures. Lastly, a 2-dimensional heat transfer model was used to understand heat flow through the powder compacts.

Zirconium phase transformations observed by “in-situ” XRD analysis

Vacuum ◽  
2012 ◽  
Vol 86 (6) ◽  
pp. 785-788 ◽  
Author(s):  
Jan Riha ◽  
Pavol Sutta ◽  
Andrej Vincze ◽  
Rostislav Medlin
Keyword(s):  
Phase Transformations ◽  
Xrd Analysis ◽  
In Situ Xrd

Observation on the Structure of Ordered Mesoporous Materials at High Temperature via In Situ X-Ray Diffraction

2010 ◽  
Vol 132 ◽  
pp. 29-37
Author(s):  
Chun Fang Zhou ◽  
Jian Hua Zhu
Keyword(s):  
High Temperature ◽  
Mesoporous Materials ◽  
Pore Wall ◽  
Short Paper ◽  
Structure Variation ◽  
Ordered Mesoporous Materials ◽  
In Situ Xrd ◽  
Mesoscopic Structure ◽  
Xrd Patterns

This short paper reports the direct observation of the structure variation of mesoporous silica at temperatures higher than 600 oC by use of an in situ XRD technique. The mesostructure of SBA-15 or other mesoporous materials such as MCM-41 became almost invisible when the temperature rose to above 600 oC, but recovered or partially recovered once the temperature decreased. Contrarily, the characteristic XRD patterns of zeolites such as ZSM-5 kept unchangeable under the same conditions. On the basis of comparative experiments performed on various mesoporous samples, it is inferred that the reversible variation of XRD patterns probably originates from the thermal shock of the pore wall, not from the permanent collapse of the mesoscopic structure in these samples. This observation indicates the special features of SBA-15 at high temperature.

scholarly journals Effect of Soil Solution pH during the Tetracycline Intercalation on the Structural Properties of a Dioctahedral Smectite: Microstructural Analysis

2019 ◽  
Vol 2019 ◽  
pp. 1-17
Author(s):  
Walid Oueslati
Keyword(s):  
Soil Solution ◽  
Structural Changes ◽  
Ph Value ◽  
Microstructural Analysis ◽  
Xrd Analysis ◽  
Deformation Bands ◽  
Solution Ph ◽  
Hydration Properties ◽  
In Situ Xrd

The aim of this work is to quantitatively characterize the structural response to a chemical disruption of saturated montmorillonite crystallites by organic molecules (tetracycline (TC)), derived from pharmaceutical waste. The chemical disturbance is performed by varying the surrounding soil solution pH. To show the effect of this chemical perturbation on the interlamellar space (IS) configuration and the hydration properties, an “in situ” XRD analysis, based on the modeling of the 00l reflections, is carried out. The “in situ” XRD analysis is performed by varying the relative humidity conditions (%RH). FTIR SEM and BET- (Brunauer-Emmett-Teller-) BJH (Barrett-Joyner-Halenda) analyses are used as complementary techniques to confirm the structural changes accompanying the intercalation process. Results showed a dependence between solution acid character and the TC adsorption mechanism. From pH values close to 7, the deprotonation of the TC molecule within IS is accelerated by an increasing %RH rate. IR spectroscopy shows that the structure is preserved versus pH value and only a shift of the water deformation bands ascribed to interlamellar water molecule abundance and TC conformation is observed. The surface morphology studied by SEM shows the increase in the surface porosity by increasing the pH value. BET-specific surface area and BJH pore size distribution (PSD) analyses confirm the SEM observations.

Studying the Progress of Sintering in Ferrous Powder Compacts by In-Situ Measuring the Thermal Conductivity

2018 ◽  
Vol 18 (2) ◽  
pp. 80-95
Author(s):  
H. Danninger ◽  
G. Leitner ◽  
Ch. Gierl-Mayer
Keyword(s):  
Thermal Conductivity ◽  
Laser Flash ◽  
Sintering Process ◽  
In Situ Characterization ◽  
Dimensional Changes ◽  
Flow Through ◽  
Powder Compacts ◽  
Good Agreement

Abstract In situ characterization of the sintering process is a difficult task, in particular for systems without pronounced dimensional changes. Dilatometry is not too helpful in those cases, and therefore other properties have to be recorded. In the present study, sintering of ferrous powder compacts was studied in situ by measuring the thermal diffusivity a using a laser flash apparatus. This property is a measure to characterise the heat flow through a material; it depends on the contact area between the particles and thus reveals their change during sintering. It is shown that the change of a during sintering of ferrous compacts is much less pronounced than in the case of cemented carbides which is not surprising when regarding the widely differing porosity changes. The results are however in good agreement with expectations when considering some experimental limitations. The trend for the thermal conductivity λ. which can be calculated from a, the specific heat and the density, is in good agreement with that found for the electrical conductivity, both properties being linked through Wiedemann-Franz’ law.

In situ XRD analysis of the oxide layers formed by oxidation at 743 K on Zircaloy 4 and Zr–1NbO

2000 ◽  
Vol 280 (3) ◽  
pp. 318-330 ◽  
Author(s):  
N. Pétigny ◽  
P. Barberis ◽  
C. Lemaignan ◽  
Ch. Valot ◽  
M. Lallemant
Keyword(s):  
Xrd Analysis ◽  
Oxide Layers ◽  
In Situ Xrd

In situ Raman and in situ XRD analysis of PdO reduction and Pd° oxidation supported on γ-Al2O3 catalyst under different atmospheres

2011 ◽  
Vol 13 (10) ◽  
pp. 4607 ◽  
Author(s):  
Alexandre Baylet ◽  
Patrice Marécot ◽  
Daniel Duprez ◽  
Paola Castellazzi ◽  
Gianpiero Groppi ◽  
...  
Keyword(s):  
Xrd Analysis ◽  
In Situ Xrd ◽  
In Situ Raman ◽  
Al2o3 Catalyst

In situ XRD analysis of Ni(Pt)/Si(100) reactions in low temperature regime ≤400°C

2003 ◽  
Vol 128 (9-10) ◽  
pp. 325-328 ◽  
Author(s):  
P.S. Lee ◽  
K.L. Pey ◽  
D. Mangelinck ◽  
J. Ding ◽  
L. Chan
Keyword(s):  
Low Temperature ◽  
Temperature Regime ◽  
Xrd Analysis ◽  
In Situ Xrd

scholarly journals Limestone calcination under calcium-looping conditions for CO2 capture and thermochemical energy storage in the presence of H2O: an in situ XRD analysis

2017 ◽  
Vol 19 (11) ◽  
pp. 7587-7596 ◽  
Author(s):  
Jose Manuel Valverde ◽  
Santiago Medina
Keyword(s):  
Crystal Structure ◽  
Energy Storage ◽  
Co2 Capture ◽  
Xrd Analysis ◽  
In Situ Xrd ◽  
Calcium Looping ◽  
Low Concentrations ◽  
Limestone Calcination

The presence of H2O at very low concentrations in the calciner significantly accelerates decomposition, while the resulting CaO crystal structure and reactivity are not modified.

In situ XRD analysis of dolomite calcination under CO2 in a humid environment

CrystEngComm ◽  
2020 ◽  
Vol 22 (39) ◽  
pp. 6502-6516 ◽  
Author(s):  
Santiago Medina-Carrasco ◽  
Jose Manuel Valverde
Keyword(s):  
Xrd Analysis ◽  
In Situ Xrd ◽  
Humid Environment

In situ XRD analysis on the calcination and decrepitation of natural dolomite under pure CO2 atmosphere and influence of humidity under conditions relevant for CO2 capture.

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