Application of synchrotron X-ray radiography to the study of dendritic equiaxed microstructure formation in Al–Cu alloys

In contrast to the inability of x-ray microanalysis to detect Li, secondary ion mass spectrometry (SIMS) generates a very strong Li+ signal. The latter’s potential was recently exploited by Williams et al. in the study of binary Al-Li alloys. The present study of Al-Li-Cu was done using the high resolution scanning ion microprobe (SIM) at the University of Chicago (UC). The UC SIM employs a 40 keV, ∼70 nm diameter Ga+ probe extracted from a liquid Ga source, which is scanned over areas smaller than 160×160 μm2 using a 512×512 raster. During this experiment, the sample was held at 2 × 10-8 torr.In the Al-Li-Cu system, two phases of major importance are T1 and T2, with nominal compositions of Al2LiCu and Al6Li3Cu respectively. In commercial alloys, T1 develops a plate-like structure with a thickness <∼2 nm and is therefore inaccessible to conventional microanalytical techniques. T2 is the equilibrium phase with apparent icosahedral symmetry and its presence is undesirable in industrial alloys.

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Soft-X-Ray Appearance Potential Spectra of Ni/Cu Alloys

Physical Review Letters ◽

10.1103/physrevlett.29.218 ◽

1972 ◽

Vol 29 (4) ◽

pp. 218-220 ◽

Cited By ~ 47

Author(s):

G. Ertl ◽

K. Wandelt

Keyword(s):

X Ray ◽

Appearance Potential ◽

Cu Alloys

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X-ray diffraction study of thermal parameters of Pd, Pd–Ag and Pd–Ag–Cu alloys as hydrogen purification membrane materials

Physica B Condensed Matter ◽

10.1016/j.physb.2015.12.048 ◽

2016 ◽

Vol 484 ◽

pp. 42-47 ◽

Cited By ~ 7

Author(s):

Subhasis Pati ◽

Ram Avtar Jat ◽

S.K. Mukerjee ◽

S.C. Parida

Keyword(s):

Diffraction Study ◽

Thermal Parameters ◽

Hydrogen Purification ◽

X Ray Diffraction ◽

Membrane Materials ◽

X Ray ◽

Cu Alloys

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Observation of microstructure change during freeze-drying by in-situ X-ray Computed Tomography

Proceedings of 21th International Drying Symposium ◽

10.4995/ids2018.2018.7642 ◽

2018 ◽

Author(s):

Kyuya Nakagawa ◽

Shinri Tamiya ◽

Shu Sakamoto ◽

Gabsoo Do ◽

Shinji Kono ◽

...

Keyword(s):

Computed Tomography ◽

Freeze Drying ◽

Glassy State ◽

Structural Deformation ◽

Microstructure Formation ◽

Microstructure Change ◽

X Ray ◽

X Ray Computed ◽

The Many

X-ray computed tomography technique was used to observe microstructure formation during freeze-drying. A specially designed vacuum freeze-drying stage was equipped at the X-ray CT stage, and the frozen and dried microstructures of dextrin solutions were successfully observed. It was confirmed that the many parts of the pore microstructures formed as a replica of the original ice microstructures, whereas some parts formed as a consequence of the dehydration dependent on the relaxation level of the glassy phases, suggesting that the post-freezing annealing is advantageous for avoiding quality loss that relates to the structural deformation of glassy matters. Keywords: freeze-drying; X-ray CT; ice microstructure; glassy state

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Phase Equilibria and Solidification of Al-Rich Ai-Ui-Cu Alloys

MRS Proceedings ◽

10.1557/proc-186-141 ◽

1990 ◽

Vol 186 ◽

Cited By ~ 1

Author(s):

Sinn-Wen Chen ◽

Y. Austin Chang

Keyword(s):

Liquidus Projection ◽

Thermodynamic Description ◽

Type Equation ◽

Ternary Alloys ◽

X Ray Diffraction ◽

Thermodynamic Models ◽

Isothermal Sections ◽

X Ray ◽

Cu Alloys ◽

Calculated Amount

AbstractA liquidus projection of the Al-rich Al-Li-Cu system is proposed. The proposed liquidus projection was based on DTA, X-ray diffraction, metallography, EPMA, SEM, and chemical analysis of 50 ternary alloys. Using these data and those reported in the literature, and thermodynamic models of Al-Li, AI-Cu and Cu-Li, a thermodynamic description of the Al-rich AI-Li-Cu system was developed. The calculated isothermal sections at several temperatures and the liquidus projection are in agreement with the experimental determinations. Combining the thermodynamic models and a Scheil-type equation, quantitative solidification paths were described. The calculated amount of primary solidification phase was compared to the experimental determination.

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Revisiting Models for Spheroidal Graphite Growth

Materials Science Forum ◽

10.4028/www.scientific.net/msf.925.118 ◽

2018 ◽

Vol 925 ◽

pp. 118-124 ◽

Cited By ~ 5

Author(s):

Mathias Karsten Bjerre ◽

Mohammed Azeem ◽

Peter D. Lee ◽

Jesper Henri Hattel ◽

Niels Skat Tiedje

Keyword(s):

Growth Rate ◽

Cast Iron ◽

Numerical Model ◽

Final Stage ◽

Nucleation And Growth ◽

Ductile Cast Iron ◽

Spheroidal Graphite ◽

Microstructure Formation ◽

X Ray ◽

Graphite Growth

Recent experiments resolved nucleation and growth of graphite during solidification of ductile cast iron in 4D using synchrotron X-ray tomography. A numerical model for microstructure formation during solidification is compared with the experiments. Despite very good overall agreement between observations of spheroidal graphite growth and model results, significant deviations exist towards the end of solidification. We use the experimental observations to analyse the relation between graphite growth rate and the state of the particle neighbourhood to pinpoint possible links between growth rate of individual graphite spheres and the overall solidification state. With this insight we revisit existing models for growth of spheroidal graphite and discuss possible modifications in order to correctly describe the critical final stage of solidification.

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