In Situ and Ex Situ Characterization of the Microstructure Formation in Ni-Cr-Si Alloys during Rapid Solidification—Toward Alloy Design for Laser Additive Manufacturing

Laser beam-based deposition methods such as laser cladding or additive manufacturing of metals promises improved properties, performance, and reliability of the materials and therefore rely heavily on understanding the relationship between chemical composition, rapid solidification processing conditions, and resulting microstructural features. In this work, the phase formation of four Ni-Cr-Si alloys was studied as a function of cooling rate and chemical composition using a liquid droplet rapid solidification technique. Post mortem x-ray diffraction, scanning electron microscopy, and in situ synchrotron microbeam X-ray diffraction shows the present and evolution of the rapidly solidified microstructures. Furthermore, the obtained results were compared to standard laser deposition tests. In situ microbeam diffraction revealed that due to rapid cooling and an increasing amount of Cr and Si, metastable high-temperature silicides remain in the final microstructure. Due to more sluggish interface kinetics of intermetallic compounds than that of disorder solid solution, an anomalous eutectic structure becomes dominant over the regular lamellar microstructure at high cooling rates. The rapid solidification experiments produced a microstructure similar to the one generated in laser coating thus confirming that this rapid solidification test allows a rapid pre-screening of alloys suitable for laser beam-based processing techniques.

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Dendrite remelting during rapid solidification of undercooled CoSi-CoSi2 eutectic alloys quantified by in situ synchrotron X-ray diffraction

Scripta Materialia ◽

10.1016/j.scriptamat.2020.113645 ◽

2021 ◽

Vol 194 ◽

pp. 113645

Author(s):

Evan B. Baker ◽

Sangho Jeon ◽

Olga Shuleshova ◽

Ivan Kaban ◽

Yeqing Wang ◽

...

Keyword(s):

Rapid Solidification ◽

Eutectic Alloys ◽

X Ray Diffraction ◽

X Ray

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In‐Situ Investigation of the Rapid Solidification Behavior of Intermetallic γ‐TiAl Based Alloys Using High‐Energy X‐Ray Diffraction

Advanced Engineering Materials ◽

10.1002/adem.202100557 ◽

2021 ◽

Author(s):

Gloria Graf ◽

Jan Rosigkeit ◽

Erwin Krohmer ◽

Peter Staron ◽

Raimund Krenn ◽

...

Keyword(s):

Rapid Solidification ◽

High Energy ◽

Solidification Behavior ◽

X Ray Diffraction ◽

X Ray ◽

In Situ Investigation

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In Situ X-Ray Diffraction Investigations during Diffusion Anneals of Ni-Cu Thin Film Diffusion Couples

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.89-91.503 ◽

2010 ◽

Vol 89-91 ◽

pp. 503-508 ◽

Cited By ~ 1

Author(s):

J. Sheng ◽

U. Welzel ◽

Eric J. Mittemeijer

Keyword(s):

Thermal Stresses ◽

Stress Generation ◽

Ex Situ ◽

Diffusion Annealing ◽

X Ray Diffraction ◽

Individual Layer ◽

X Ray ◽

Bilayer System ◽

Stress Changes

The stress evolution during diffusion annealing of Ni-Cu bilayers (individual layer thicknesses of 50 nm) was investigated employing ex-situ and in-situ X-ray diffraction measurements. Annealing at relatively low homologous temperatures (about 0.3 - 0.4 Tm) for durations up to about 100 hours results in considerable diffusional intermixing, as demonstrated by Auger-electron spectroscopy investigations (in combination with sputter-depth profiling). In addition to thermal stresses due to differences of the coefficients of thermal expansion of layers and substrate, tensile stress con-tributions in the sublayers arise during the diffusion anneals. The obtained stress data have been discussed in terms of possible mechanisms of stress generation. The influence of diffusion on stress development in the sublayers of the diffusion couple during heating and isothermal annealing was investigated by comparing stress changes in the bilayer system with corresponding results obtained under identical conditions for single layers of the components in the bilayer system. The specific residual stresses that emerge due to diffusion between the (sub)layers in the bilayer could thereby be identified.

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Size dependent behavior of Fe3O4crystals during electrochemical (de)lithiation: an in situ X-ray diffraction, ex situ X-ray absorption spectroscopy, transmission electron microscopy and theoretical investigation

Physical Chemistry Chemical Physics ◽

10.1039/c7cp03312e ◽

2017 ◽

Vol 19 (31) ◽

pp. 20867-20880 ◽

Cited By ~ 27

Author(s):

David C. Bock ◽

Christopher J. Pelliccione ◽

Wei Zhang ◽

Janis Timoshenko ◽

K. W. Knehr ◽

...

Keyword(s):

Electron Microscopy ◽

Structural Changes ◽

Ex Situ ◽

X Ray Diffraction ◽

X Ray ◽

Size Dependent ◽

Transmission Electron ◽

Dependent Behavior ◽

X Ray Absorption

Crystal and atomic structural changes of Fe3O4upon electrochemical (de)lithiation were determined.

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A study on preparation and characterization of carbon doped TiO2 nanotubes

Malaysian Journal of Fundamental and Applied Sciences ◽

10.11113/mjfas.v6n1.167 ◽

2014 ◽

Vol 6 (1) ◽

Cited By ~ 1

Author(s):

Srimala Sreekantan ◽

Roshasnorlyza Hazan ◽

Zainovia Lockman ◽

Ishak Mat

Keyword(s):

Methyl Orange ◽

Tio2 Nanotubes ◽

Pure Tio2 ◽

Ex Situ ◽

X Ray Diffraction ◽

Methyl Orange Degradation ◽

Doped Tio2 ◽

X Ray ◽

Carbon Doped

The present study is directed to clarify the influence of carbon doping on the degradation of methyl orange. TiO2 nanotubes were prepared by anodizing titanium foils in a two electrode configuration bath with titanium foil as the anode and platinum as the counter electrode. The electrochemical bathconsists of 1 M Na2SO4 with 0.7 g ammonium fluoride, NH4F. The nanotubes obtained were further doped with carbon via in-situ and ex-situ method. Incorporation of carbon on TiO2 via in-situ method is accomplished during the anodization process by introducing oxalic acid into electrolyte while theex-situ doping involves carbon incorporation into pre-fabricated TiO2 nanotube via flame annealing using carbon blackN330. Characterization such as Scanning Electron Microscope (SEM), Energy Dispersive X-ray Analysis (EDX), and X-Ray Diffraction (XRD) are used to determine the surfacemorphology, composition of dopants, and phases exists. Well ordered nanotube with good adherence and smooth surface was obtained for both methods. When the oxide was annealed, X-ray diffraction analysis revealed the presence of anatase and rutile phase. The photocatalytic properties of thepure TiO2 and carbon doped TiO2 were tested for methyl orange degradation and the result indicated that the in-situ doped TiO2 has much better degradation than the ex-situ and pure TiO2. The percentage of methyl orange degradation for in-situ was 20% and 41% higher than ex-situ doped TiO2 and pure TiO2, respectively.

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The Viscosity and Atomic Structure of Volatile-Bearing Melilititic Melts at High Pressure and Temperature and the Transport of Deep Carbon

Minerals ◽

10.3390/min10030267 ◽

2020 ◽

Vol 10 (3) ◽

pp. 267 ◽

Cited By ~ 2

Author(s):

Vincenzo Stagno ◽

Veronica Stopponi ◽

Yoshio Kono ◽

Annalisa D’Arco ◽

Stefano Lupi ◽

...

Keyword(s):

Experimental Data ◽

High Pressure ◽

Atomic Structure ◽

Ex Situ ◽

X Ray Diffraction ◽

High Pressure And Temperature ◽

X Ray ◽

Falling Sphere ◽

Basaltic Melts

Understanding the viscosity of mantle-derived magmas is needed to model their migration mechanisms and ascent rate from the source rock to the surface. High pressure–temperature experimental data are now available on the viscosity of synthetic melts, pure carbonatitic to carbonate–silicate compositions, anhydrous basalts, dacites and rhyolites. However, the viscosity of volatile-bearing melilititic melts, among the most plausible carriers of deep carbon, has not been investigated. In this study, we experimentally determined the viscosity of synthetic liquids with ~31 and ~39 wt% SiO2, 1.60 and 1.42 wt% CO2 and 5.7 and 1 wt% H2O, respectively, at pressures from 1 to 4.7 GPa and temperatures between 1265 and 1755 °C, using the falling-sphere technique combined with in situ X-ray radiography. Our results show viscosities between 0.1044 and 2.1221 Pa·s, with a clear dependence on temperature and SiO2 content. The atomic structure of both melt compositions was also determined at high pressure and temperature, using in situ multi-angle energy-dispersive X-ray diffraction supported by ex situ microFTIR and microRaman spectroscopic measurements. Our results yield evidence that the T–T and T–O (T = Si,Al) interatomic distances of ultrabasic melts are higher than those for basaltic melts known from similar recent studies. Based on our experimental data, melilititic melts are expected to migrate at a rate ~from 2 to 57 km·yr−1 in the present-day or the Archaean mantle, respectively.

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PHASE FORMATION AND TEXTURE DEVELOPMENT IN AG-SHEATHED Bi, Pb(2223) TAPES STUDIED BY DIFFERENT IN-SITU AND EX-SITU DIFFRACTION TECHNIQUES

International Journal of Modern Physics B ◽

10.1142/s0217979200002788 ◽

2000 ◽

Vol 14 (25n27) ◽

pp. 2688-2693 ◽

Cited By ~ 4

Author(s):

E. GIANNINI ◽

E. BELLINGERI ◽

F. MARTI ◽

M. DHALLÉ ◽

V. HONKIMÄKI ◽

...

Keyword(s):

High Energy ◽

Texture Development ◽

Ex Situ ◽

X Ray Diffraction ◽

X Ray ◽

Scattering Geometry ◽

Reflection Geometry ◽

Comparison Of The Results ◽

In Situ Neutron Diffraction

In-situ and ex-situ high energy (80÷88 keV) X-Ray diffraction from a synchrotron radiation source were performed on multifilamentary Bi, Pb(2223)/Ag tapes using a transmission scattering geometry. Several thermo-mechanical procedures were compared, focusing mainly on the texture development of both Bi, Pb(2212) and Bi, Pb(2223) phases. The effect of the periodic pressing on the texture and on the critical current is elucidated. The texture development of the Bi, Pb(2212) phase prior to its transformation into Bi, Pb(2223) was directly observed in-situ at high temperature by using a dedicated high-energy X-ray compatible furnace and a high resolution Image Plate detector. A sharp increase of the Bi, Pb(2212) grain orientation along the [00l] direction was found to occur only above 750°C. Normal state transport measurements are in full agreement with the formation mechanism and with the texture development observed. A comparison of the results with the ones provided by in-situ neutron diffraction and standard low-energy XRD in a reflection geometry is presented.

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A Combined Experimental and Theoretical Study of Lithiation Mechanism in ZnFe2O4 Anode Materials

MRS Advances ◽

10.1557/adv.2018.305 ◽

2018 ◽

Vol 3 (14) ◽

pp. 773-778 ◽

Cited By ~ 4

Author(s):

Lei Wang ◽

Alison McCarthy ◽

Kenneth J. Takeuchi ◽

Esther S. Takeuchi ◽

Amy C. Marschilok

Keyword(s):

Early Stage ◽

Deep Understanding ◽

Lithium Ion ◽

Oxidation Products ◽

Ex Situ ◽

Theoretical Modelling ◽

X Ray Diffraction ◽

X Ray ◽

X Ray Absorption

ABSTRACTZnFe2O4 (ZFO) represents a promising anode material for lithium ion batteries, but there is still a lack of deep understanding of the fundamental reduction mechanism associated with this material. In this paper, the complete visualization of reduction/oxidation products irrespective of their crystallinity was achieved experimentally through a compilation of in situ X-ray diffraction, synchrotron based powder diffraction, and ex-situ X-ray absorption fine structure data. Complementary theoretical modelling study further shed light upon the fundamental understanding of the lithiation mechanism, especially at the early stage from ZnFe2O4 up to LixZnFe2O4 (x = 2).

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