In-Situ Synchrotron Diffraction and Modeling of Non-Equilibrium Solidification of a MnFeCoNiCu Alloy

Abstract The solidification mechanism and segregation behavior of laser-melted Mn35Fe5Co20Ni20Cu20 was firstly investigated via in-situ synchrotron x-ray diffraction at millisecond temporal resolution. The transient composition evolution of the random solid solution during sequential solidification of dendritic and interdendritic regions complicates the analysis of synchrotron diffraction data via any single conventional tool, such as Rietveld refinement. Therefore, a novel approach combining a hard-sphere approximation model, thermodynamic simulation, thermal expansion measurement and microstructural characterization was developed to assist in a fundamental understanding of the evolution of local composition, lattice parameter, and dendrite volume fraction corresponding to the diffraction data. This methodology yields self-consistent results across different methods. Via this approach, four distinct stages were identified, including: (I) FCC dendrite solidification, (II) solidification of FCC interdendritic region, (III) solid-state interdiffusion and (IV) final cooling with marginal diffusion. It was found out that in Stage I, Cu and Mn were rejected into liquid as Mn35Fe5Co20Ni20Cu20 solidified dendritically. During Stage II, the lattice parameter disparity between dendrite and interdendritic region escalated as Cu and Mn continued segregating into the interdendritic region. After complete solidification, during Stage III, the lattice parameter disparity gradually decreases, demonstrating a degree of composition homogenization. The volume fraction of dendrites slightly grew from 58.3–65.5%, based on the evolving composition profile across a dendrite/interdendritic interface in diffusion calculations. Postmortem metallography further confirmed that dendrites have a volume fraction of 64.7% ± 5.3% in the final microstructure.

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In situ synchrotron diffraction and modeling of non-equilibrium solidification of a MnFeCoNiCu alloy

Scientific Reports ◽

10.1038/s41598-021-85430-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Benjamin Schneiderman ◽

Andrew Chihpin Chuang ◽

Peter Kenesei ◽

Zhenzhen Yu

Keyword(s):

Diffraction Data ◽

Interdendritic Region ◽

Volume Fraction ◽

Thermodynamic Simulation ◽

Microstructural Characterization ◽

Lattice Parameter ◽

Synchrotron Diffraction ◽

Local Composition ◽

Novel Approach

AbstractThe solidification mechanism and segregation behavior of laser-melted Mn35Fe5Co20Ni20Cu20 was firstly investigated via in situ synchrotron x-ray diffraction at millisecond temporal resolution. The transient composition evolution of the random solid solution during sequential solidification of dendritic and interdendritic regions complicates the analysis of synchrotron diffraction data via any single conventional tool, such as Rietveld refinement. Therefore, a novel approach combining a hard-sphere approximation model, thermodynamic simulation, thermal expansion measurement and microstructural characterization was developed to assist in a fundamental understanding of the evolution of local composition, lattice parameter, and dendrite volume fraction corresponding to the diffraction data. This methodology yields self-consistent results across different methods. Via this approach, four distinct stages were identified, including: (I) FCC dendrite solidification, (II) solidification of FCC interdendritic region, (III) solid-state interdiffusion and (IV) final cooling with marginal diffusion. It was found out that in Stage I, Cu and Mn were rejected into liquid as Mn35Fe5Co20Ni20Cu20 solidified dendritically. During Stage II, the lattice parameter disparity between dendrite and interdendritic region escalated as Cu and Mn continued segregating into the interdendritic region. After complete solidification, during Stage III, the lattice parameter disparity gradually decreases, demonstrating a degree of composition homogenization. The volume fraction of dendrites slightly grew from 58.3 to 65.5%, based on the evolving composition profile across a dendrite/interdendritic interface in diffusion calculations. Postmortem metallography further confirmed that dendrites have a volume fraction of 64.7% ± 5.3% in the final microstructure.

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Derivation of d-Values from Digitized X-ray and Synchrotron Diffraction Data

Advances in X-ray Analysis ◽

10.1154/s0376030800019698 ◽

1989 ◽

Vol 33 ◽

pp. 295-303 ◽

Cited By ~ 6

Author(s):

T. C. Huang ◽

W. Parrish ◽

N. Masciocchi ◽

P. W. Wang

Keyword(s):

Diffraction Data ◽

Practical Method ◽

Xrd Analysis ◽

Lattice Parameter ◽

Lattice Parameters ◽

Synchrotron Diffraction ◽

Experimental Conditions ◽

X Ray ◽

D Values

AbstractA precise and practical method for the determination of d-values and lattice parameters from digital diffraction data is described. Systematic errors are corrected mathematically during a d-spacing / lattice-parameter least-Squares refincment process making it unnecessary to use internal standards. X-ray and synchrotron diffraction data of an ICDD alumina plate obtained with a wide variety of experimental conditions and analysis parameters were used to study the precision in the derivation of d-values and the accuracy in the determination of lattice parameters. Results showed that the precision in determining d-values was high with |Δd/d|avg ranging from 2x105 to 4x10-5. Using the results obtained from the high precision XRD analysis as a reference standard, the accuracy in the lattice parameter determinations from the synchrotron diffraction data reached the l-2x10-6] range. Lattice parameters, with an accuracy in the high 10-5 range, were also obtained using parameters commonly used in a routine XRD analysis such as a wide RS (0.11°) for high intensity, peaks only in the front reflection region, no Kα2 stripping, and a Single 2θo parameter for systematic error corrections.

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Determination of Residual Stresses in an Oxidized Metallic Alloy under Thermal Loadings

Metals ◽

10.3390/met8110913 ◽

2018 ◽

Vol 8 (11) ◽

pp. 913

Author(s):

Zhimao Wang ◽

Jean-Luc Grosseau-Poussard ◽

Benoît Panicaud ◽

Guillaume Geandier ◽

Pierre-Olivier Renault ◽

...

Keyword(s):

Residual Stresses ◽

Correction Method ◽

Lattice Parameter ◽

European Synchrotron Radiation Facility ◽

X Ray Diffraction ◽

Synchrotron Diffraction ◽

X Ray ◽

Crystallographic Planes

In order to clarify the mechanical features of a metal under thermal cyclic loading for the system Ni30Cr-Cr2O3, a specific study has been carried out. In the present work, the residual stresses in both the metal and the oxide layer have been investigated. An adapted method is applied to process the experimental results that were obtained by using in-situ high temperature synchrotron diffraction at European Synchrotron Radiation Facility. The sin2ψ analysis provides information about the stress in metal and oxide. X-ray diffraction provides also the lattice parameter between crystallographic planes in the metal. To obtain correct stress values, a correction method is also proposed taking into account different discrepancies sources to ensure the equation of mechanical balance.

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Application of Advanced Experimental Techniques for the Microstructural Characterization of Nanobainitic Steels

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.172-174.1249 ◽

2011 ◽

Vol 172-174 ◽

pp. 1249-1254 ◽

Cited By ~ 4

Author(s):

Ilana Timokhina ◽

Hossein Beladi ◽

Xiang Yuan Xiong ◽

Yoshitaka Adachi ◽

Peter D. Hodgson

Keyword(s):

Dislocation Density ◽

Carbon Content ◽

Retained Austenite ◽

Volume Fraction ◽

Accurate Determination ◽

Bainitic Ferrite ◽

Microstructural Characterization ◽

Atom Probe ◽

Isothermal Heat Treatment ◽

Local Composition

A 0.79C-1.5Si-1.98Mn-0.98Cr-0.24Mo-1.06Al-1.58Co (wt%) steel was isothermally heat treated at 350°C bainitic transformation temperature for 1 day to form fully bainitic structure with nano-layers of bainitic ferrite and retained austenite, while a 0.26C-1.96Si-2Mn-0.31Mo (wt%) steel was subjected to a successive isothermal heat treatment at 700°C for 300 min followed by 350°C for 120 min to form a hybrid microstructure consisting of ductile ferrite and fine scale bainite. The dislocation density and morphology of bainitic ferrite, and retained austenite characteristics such as size, and volume fraction were studied using Transmission Electron Microscopy. It was found that bainitic ferrite has high dislocation density for both steels. The retained austenite characteristics and bainite morphology were affected by composition of steels. Atom Probe Tomography (APT) has the high spatial resolution required for accurate determination of the carbon content of the bainitic ferrite and retained austenite, the solute distribution between these phases and calculation of the local composition of fine clusters and particles that allows to provide detailed insight into the bainite transformation of the steels. The carbon content of bainitic ferrite in both steels was found to be higher compared to the para-equilibrium level of carbon in ferrite. APT also revealed the presence of fine C-rich clusters and Fe-C carbides in bainitic ferrite of both steels.

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Characterization of γ′ Precipitates in Cast Ni-Based Superalloy and Their Behaviour at High-Homologous Temperatures Studied by TEM and in Situ XRD

Materials ◽

10.3390/ma13102397 ◽

2020 ◽

Vol 13 (10) ◽

pp. 2397 ◽

Cited By ~ 3

Author(s):

Łukasz Rakoczy ◽

Ondrej Milkovič ◽

Bogdan Rutkowski ◽

Rafał Cygan ◽

Małgorzata Grudzień-Rakoczy ◽

...

Keyword(s):

Volume Fraction ◽

Matrix Material ◽

High Volume ◽

Lattice Parameter ◽

X Ray Diffraction ◽

In Situ Xrd ◽

Transmission Electron ◽

The Matrix

In situ X-ray diffraction and transmission electron microscopy has been used to investigate René 108 Ni-based superalloy after short-term annealing at high-homologous temperatures. Current work is focused on characterisation of γ′ precipitates, their volume fraction, evolution of the lattice parameter of γ and γ′ phases and misfit parameter of γ′ in the matrix. Material in the initial condition is characterised by a high-volume fraction (over 63%) of γ′ precipitates. Irregular distribution of alloying elements was observed. Matrix channels were strongly enriched in Cr, Co, W and Mo, whereas precipitates contain large amount of Al, Ti, Ta and Hf. Exposure to high-homologous temperatures in the range 1100–1250 °C led to the dissolution of the precipitates, which influenced the change of lattice parameter of both γ and γ′ phases. The lattice parameter of the matrix continuously grew during holding at high temperatures, which had a dominant influence on the more negative misfit coefficient.

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Microstrucrure and Properties of In-Situ R. F. Sputtered YBa2Cu3O7−x Thin Films for Microwave Applications

MRS Proceedings ◽

10.1557/proc-275-513 ◽

1992 ◽

Vol 275 ◽

Author(s):

David W. Reagor ◽

Margarita E. Piza ◽

Robert J. Houlton ◽

Fernando H. Garzon ◽

Marilyn Hawley ◽

...

Keyword(s):

Surface Resistance ◽

Volume Fraction ◽

Film Surface ◽

Lattice Parameter ◽

Scanning Tunneling ◽

Tunneling Microscopy ◽

Free Film ◽

Film Substrate ◽

Deposition Conditions

ABSTRACTThe residual surface resistance of a number of films of YBa2Cu3O7−x, prepared by off-axis sputtering onto MgO substrates, has been measured using a parallel-plate resonator technique. Deposition conditions were kept constant, apart from the substrate temperature. There is no correlation between surface resistance and other important microscopic parameters, such as Tc and c-axis lattice parameter. There is, however, a trend to higher Rs with increasing volume fraction of in-plane misoriented material, although the correlation is not perfect. Furthermore, we have found that most of the misoriented material is localized at the film substrate interface and, therefore, is probably not responsible for most of the RF losses. The data suggest that at higher deposition temperatures, there is an increasing tendency for 45° misoriented material to appear in the films, and a significant fraction of this material may be present closer to the free film surface. Scanning Tunneling Microscopy (STM) qualitatively supports this conclusion.

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In situ X-ray and neutron powder diffraction study of LaNi5-x Snx–H systems

MRS Proceedings ◽

10.1557/proc-837-n1.8 ◽

2004 ◽

Vol 837 ◽

Cited By ~ 1

Author(s):

Yumiko Nakamura ◽

Robert C. Bowman ◽

Etsuo Akiba

Keyword(s):

Neutron Diffraction ◽

Diffraction Data ◽

Lattice Strain ◽

Profile Analysis ◽

Lattice Parameter ◽

Hydride Phase ◽

Neutron Diffraction Data ◽

X Ray ◽

Hydrogen Deuterium

ABSTRACTWe have studied structural change and lattice strain formation during absorption and desorption of hydrogen (deuterium) by high purity LaNi5-x Snx alloys (x = 0.22, 0.25) using in situ X-ray and neutron diffraction along with simultaneously measuring the P-C isotherms. From profile analysis of the X-ray diffraction data, lattice parameter and lattice strain in each hydriding state are evaluated. In situ neutron diffraction data provided hydrogen occupation changing with hydrogen content. Significant lattice contract and strain formation were observed in the hydride phase in desorption. This behavior was related with decrease in hydrogen occupation in the hydride phase revealed from the neutron diffraction data.

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Microstructural characterization of a rapidly solidified Al-Fe-V-Si alloy for elevated temperature applications

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100104819 ◽

1988 ◽

Vol 46 ◽

pp. 550-551

Author(s):

R. E. Franck ◽

J. A. Hawk ◽

G. J. Shiflet

Keyword(s):

High Temperature ◽

Elevated Temperature ◽

Grain Growth ◽

Volume Fraction ◽

Microstructural Characterization ◽

Second Phase ◽

Microstructural Stability ◽

Elevated Temperature Strength ◽

Temperature Applications

Rapid solidification processing (RSP) is one method of producing high strength aluminum alloys for elevated temperature applications. Allied-Signal, Inc. has produced an Al-12.4 Fe-1.2 V-2.3 Si (composition in wt pct) alloy which possesses good microstructural stability up to 425°C. This alloy contains a high volume fraction (37 v/o) of fine nearly spherical, α-Al12(Fe, V)3Si dispersoids. The improved elevated temperature strength and stability of this alloy is due to the slower dispersoid coarsening rate of the silicide particles. Additionally, the high v/o of second phase particles should inhibit recrystallization and grain growth, and thus reduce any loss in strength due to long term, high temperature annealing.The focus of this research is to investigate microstructural changes induced by long term, high temperature static annealing heat-treatments. Annealing treatments for up to 1000 hours were carried out on this alloy at 500°C, 550°C and 600°C. Particle coarsening and/or recrystallization and grain growth would be accelerated in these temperature regimes.

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Microstructural characterization of YBaCuO Films on LaAlO3 substrates

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100152872 ◽

1989 ◽

Vol 47 ◽

pp. 180-181

Author(s):

E. L. Hall ◽

A. Mogro-Campero ◽

N. Lewis ◽

L. G. Turner

Keyword(s):

Dielectric Constant ◽

Single Crystal ◽

Film Growth ◽

Microstructural Characterization ◽

Lattice Parameter ◽

Film Plane ◽

Substrate Material ◽

High Loss ◽

Amorphous Substrates ◽

High Dielectric

There have been a large number of recent studies of the growth of Y-Ba-Cu-O thin films, and these studies have employed a variety of substrates and growth techniques. To date, the highest values of Tc and Jc have been found for films grown by sputtering or coevaporation on single-crystal SrTiO3 substrates, which produces a uniaxially-aligned film with the YBa2Cu3Ox c-axis normal to the film plane. Multilayer growth of films on the same substrate produces a triaxially-aligned film (regions of the film have their c-axis parallel to each of the three substrate <100> directions) with lower values of Jc. Growth of films on a variety of other polycrystalline or amorphous substrates produces randomly-oriented polycrystalline films with low Jc. Although single-crystal SrTiO3 thus produces the best results, this substrate material has a number of undesireable characteristics relative to electronic applications, including very high dielectric constant and a high loss tangent at microwave frequencies. Recently, Simon et al. have shown that LaAlO3 could be used as a substrate for YBaCuO film growth. This substrate is essentially a cubic perovskite with a lattice parameter of 0.3792nm (it has a slight rhombohedral distortion at room temperature) and this material exhibits much lower dielectric constant and microwave loss tangents than SrTiO3. It is also interesting from a film growth standpoint since it has a slightly smaller lattice parameter than YBa2Cu3Ox (a=0.382nm, b=c/3=0.389nm), while SrTiO3 is slightly larger (a=0.3905nm).

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