Visualizing Time-Dependent Microstructural and Chemical Evolution during Molten Salt Corrosion of Ni-20Cr Model Alloy using Correlative Quasi In Situ TEM and In Situ Synchrotron X-ray Nanotomography

ABSTRACTA technique for nondestructively imaging microstructures of materials in situ, especially a technique capable of delineating the time evolution of chemical changes or damage, will greatly benefit studies of materials processing and failure. X-ray tomographic microscopy (XTM) is a high resolution, three-dimensional inspection method which is capable of imaging composite materials microstructures with a resolution of a few micrometers. Because XTM is nondestructive, it will be possible to examine materials under load or during processing, and obtain three-dimensional images of fiber positions, microcracks, and pores. This will allow direct imaging of microstructural evolution, and will provide time-dependent data for comparison to fracture mechanics and processing models.

Download Full-text

A furnace and environmental cell for thein situinvestigation of molten salt electrolysis using high-energy X-ray diffraction

Journal of Synchrotron Radiation ◽

10.1107/s0909049511039124 ◽

2011 ◽

Vol 19 (1) ◽

pp. 39-47 ◽

Cited By ~ 7

Author(s):

Mark J. Styles ◽

Matthew R. Rowles ◽

Ian C. Madsen ◽

Katherine McGregor ◽

Andrew J. Urban ◽

...

Keyword(s):

Molten Salt ◽

Inert Anode ◽

High Energy ◽

X Ray Diffraction ◽

Molten Salt Electrolysis ◽

X Ray ◽

Quantitative Measurements ◽

Materials Used ◽

Characterization Of Materials

This paper describes the design, construction and implementation of a relatively large controlled-atmosphere cell and furnace arrangement. The purpose of this equipment is to facilitate thein situcharacterization of materials used in molten salt electrowinning cells, using high-energy X-ray scattering techniques such as synchrotron-based energy-dispersive X-ray diffraction. The applicability of this equipment is demonstrated by quantitative measurements of the phase composition of a model inert anode material, which were taken during anin situstudy of an operational Fray–Farthing–Chen Cambridge electrowinning cell, featuring molten CaCl2as the electrolyte. The feasibility of adapting the cell design to investigate materials in other high-temperature environments is also discussed.

Download Full-text

Synthesis and Characterization of Magnesium Aluminate Spinel Porous Ceramics by Novel Molten Salt Method

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.697.399 ◽

2016 ◽

Vol 697 ◽

pp. 399-403 ◽

Cited By ~ 3

Author(s):

Xian Gong Deng ◽

Jun Kai Wang ◽

Hai Jun Zhang ◽

Jiang Hao Liu ◽

Shao Wei Zhang

Keyword(s):

Molten Salt ◽

Porous Ceramics ◽

Magnesium Aluminate ◽

Molten Salt Method ◽

Magnesium Aluminate Spinel ◽

X Ray Diffraction ◽

Liquid Environment ◽

X Ray

Magnesium aluminate spinel (MgAl2O4) porous ceramics were in-situ synthesized by heating the mixture of Al2O3 and MgCO3 with MgCl2 salt at 1400~1600 °C for 3 h, and then characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The morphology of as-prepared MgAl2O4 porous ceramics was dependent on the addition of MgCl2, and it indicated that the MgCl2 molten salt not only acted as a template for pore formation of the porous ceramics, but also provided a liquid environment for the synthesis of MgAl2O4.

Download Full-text

X-Ray Dynamical Diffraction in Powder Samples with Time-Dependent Particle Size Distributions

MRS Advances ◽

10.1557/adv.2019.445 ◽

2019 ◽

Vol 5 (29-30) ◽

pp. 1585-1591 ◽

Cited By ~ 1

Author(s):

Adriana Valério ◽

Sérgio L. Morelhão ◽

Alex J. Freitas Cabral ◽

Márcio M. Soares ◽

Cláudio M. R. Remédios

Keyword(s):

Particle Size ◽

Single Phase ◽

Diffraction Peak ◽

Time Dependent ◽

Peak Width ◽

Dynamical Diffraction ◽

X Ray ◽

Integrated Intensity ◽

Diffraction Effects

ABSTRACTIn situ X-ray diffraction is one of the most useful tools for studying a variety of processes, among which crystallization of nanoparticles where phase purity and size control are desired. Growth kinetics of a single phase can be completely resolved by proper analysis of the diffraction peaks as a function of time. The peak width provides a parameter for monitoring the time evolution of the particle size distribution (PSD), while the peak area (integrated intensity) is directly related to the whole diffracting volume of crystallized material in the sample. However, to precisely describe the growth kinetics in terms of nucleation and coarsening, the correlation between PSD parameters and diffraction peak widths has to be established in each particular study. Corrections in integrated intensity values for physical phenomena such as variation in atomic thermal vibrations and dynamical diffraction effects have also to be considered in certain cases. In this work, a general correlation between PSD median value and diffraction peak width is deduced, and a systematic procedure to resolve time-dependent lognormal PSDs from in situ XRD experiments is described in details. A procedure to correct the integrated intensities for dynamical diffraction effects is proposed. As a practical demonstration, this analytical procedure has been applied to the single-phase crystallization process of bismuth ferrite nanoparticles.

Download Full-text

Probing Molten Salt Flux Reactions Using Time-Resolved in Situ High-Temperature Powder X-ray Diffraction: A New Synthesis Route to the Mixed-Valence NaTi2O4

Chemistry of Materials ◽

10.1021/cm034770w ◽

2004 ◽

Vol 16 (6) ◽

pp. 1153-1159 ◽

Cited By ~ 31

Author(s):

Margret J. Geselbracht ◽

Liam D. Noailles ◽

Lien T. Ngo ◽

Jessica H. Pikul ◽

Richard I. Walton ◽

...

Keyword(s):

High Temperature ◽

Molten Salt ◽

Mixed Valence ◽

Salt Flux ◽

X Ray Diffraction ◽

Time Resolved ◽

X Ray ◽

Synthesis Route ◽

New Synthesis

Download Full-text

Chemical selectivity in structure determination by the time dependent analysis of in situ XRPD data: a clear view of Xe thermal behavior inside a MFI zeolite

Physical Chemistry Chemical Physics ◽

10.1039/c5cp02522b ◽

2015 ◽

Vol 17 (26) ◽

pp. 17480-17493 ◽

Cited By ~ 15

Author(s):

Luca Palin ◽

Rocco Caliandro ◽

Davide Viterbo ◽

Marco Milanesio

Keyword(s):

Powder Diffraction ◽

Structure Determination ◽

Time Dependent ◽

Pca Analysis ◽

Mfi Zeolite ◽

X Ray ◽

Zeolite P ◽

Chemical Selectivity ◽

Time Dependent Analysis

PSD/PCA analysis of MED data allowed to enhance the chemical selectivity in X-ray powder diffraction and to obtain Xe substructure into MFI zeolite.

Download Full-text

In Situ Observation of Solidification in an Organic Peritectic Alloy System

Materials Science Forum ◽

10.4028/www.scientific.net/msf.649.159 ◽

2010 ◽

Vol 649 ◽

pp. 159-164 ◽

Cited By ~ 6

Author(s):

J.P. Mogeritsch ◽

Sven Eck ◽

Monika Grasser ◽

Andreas Ludwig

Keyword(s):

Phase Diagram ◽

Alloy System ◽

Model Alloy ◽

Fixed Temperature ◽

Peritectic Alloy ◽

X Ray ◽

Dsc Measurements ◽

Initial Alloy ◽

In Situ Observations

Up to date very few organic substances have been reported that show a non-faceted/non-faceted (nf/nf) peritectic phase diagram in a temperature range suitable for direct observation in a micro Bridgman furnace setup. Sturz et al. [1] and Barrio et al. [2] studied the peritectic phase diagram for the organic model alloy TRIS (Tris(hydroxymenthyl)aminomethane) - NPG (Neopentylglycol). The phase diagram is based on thermal analysis by means of DSC measurements [1, 2] and evaluation of lattice parameters measured with x-ray diffractometry [2]. In the current work we present investigations on the system TRIS – NPG that have been obtained by optical investigations of directional solidification in a micro Bridgman-furnace with various initial alloy concentrations and pulling rates in a fixed temperature gradient. The phase diagram [1, 2] was confirmed by direct comparison of DSC measurements and optical investigations. Furthermore we present in situ observations of solidification in the peritectic region. They show a solidification behavior that was clearly distinguishable from the solidification in hyper- and hypoperitectic regions of the phase diagram.

Download Full-text