Early stages ofα−α′phase separation in Fe-Cr alloys: An atomistic study

2009 ◽  
Vol 79 (10) ◽  
Author(s):  
G. Bonny ◽  
D. Terentyev ◽  
L. Malerba ◽  
D. Van Neck
Keyword(s):  
Phase Separation ◽  
Early Stages ◽  
Α Phase ◽  
Atomistic Study

The β'-α' Interaction: a Study of early Stages of Phase Separation in a Fe-20%Cr-6%Al-0.5%Ti Alloy

2011 ◽  
Vol 172-174 ◽  
pp. 315-320
Author(s):  
Carlos Capdevila ◽  
Michael K. Miller ◽  
K.F. Russell ◽  
J. Chao ◽  
F.A. López
Keyword(s):  
Phase Separation ◽  
Atom Probe Tomography ◽  
Temporal Evolution ◽  
Theoretical Calculations ◽  
Three Dimensional ◽  
Atom Probe ◽  
Early Stages ◽  
Β Phase ◽  
Α Phase ◽  
Power Measurements

The temporal evolution of the microstructure resulting from phase separation into Fe-rich (α), Cr-rich (α¢), and Fe(Ti,Al) (β¢) phases of a Fe-20Cr-6Al-0.5Ti alloy has been analyzed by thermoelectric power measurements (TEP). The early stages of decomposition and the evolution of the three-dimensional microstructure have been analyzed by atom probe tomography (APT). The roles of Cr, Al, and Ti during the decomposition process have been investigated in terms of solute partitioning between the phases. Analysis of proximity histograms revealed that significant Al and Ti partitioning occurs, which is consistent with theoretical calculations. The results indicate that as the α-α¢ phase separation proceeds, Al and Ti are rejected into the α phase, which causes the β¢ phase to nucleate on the surface of the α¢ phase.

scholarly journals On the Role of Poly-Glutamic Acid in the Early Stages of Iron(III) (Oxy)(hydr)oxide Formation

Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 715
Author(s):  
Miodrag J. Lukić ◽  
Felix Lücke ◽  
Teodora Ilić ◽  
Katharina Petrović ◽  
Denis Gebauer
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Phase Separation ◽  
Fourier Transform Infrared Spectroscopy ◽  
Fourier Transform Infrared ◽  
Nucleation Theory ◽  
Classical Nucleation Theory ◽  
Oxide Formation ◽  
Early Stages ◽  
Titration Assay

Nucleation of minerals in the presence of additives is critical for achieving control over the formation of solids in biomineralization processes or during syntheses of advanced hybrid materials. Herein, we investigated the early stages of Fe(III) (oxy)(hydr)oxide formation with/without polyglutamic acid (pGlu) at low driving force for phase separation (pH 2.0 to 3.0). We employed an advanced pH-constant titration assay, X-ray diffraction, thermal analysis with mass spectrometry, Fourier Transform infrared spectroscopy, and scanning electron microscopy. Three stages were observed: initial binding, stabilization of Fe(III) pre-nucleation clusters (PNCs), and phase separation, yielding Fe(III) (oxy)(hydr)oxide. The data suggest that organic–inorganic interactions occurred via binding of olation Fe(III) PNC species. Fourier Transform Infrared Spectroscopy (FTIR) analyses revealed a plausible interaction motif and a conformational adaptation of the polypeptide. The stabilization of the aqueous Fe(III) system against nucleation by pGlu contrasts with the previously reported influence of poly-aspartic acid (pAsp). While this is difficult to explain based on classical nucleation theory, alternative notions such as the so-called PNC pathway provide a possible rationale. Developing a nucleation theory that successfully explains and predicts distinct influences for chemically similar additives like pAsp and pGlu is the Holy Grail toward advancing the knowledge of nucleation, early growth, and structure formation.

Kinetics of the α-α′ phase separation in a 14%Cr oxide dispersion steel at intermediate temperatures

2020 ◽  
pp. 129088
Author(s):  
Yael Templeman ◽  
Malki Pinkas ◽  
Eli Brosh ◽  
Einat Strumza ◽  
Shmuel Hayun ◽  
...  
Keyword(s):  
Phase Separation ◽  
Oxide Dispersion ◽  
Α Phase ◽  
Kinetics Of

scholarly journals Oxidation of polycrystalline Ni studied by spectromicroscopy: Phase separation in the early stages of crystallite growth

2010 ◽  
Vol 81 (8) ◽  
Author(s):  
A. Cornish ◽  
T. Eralp ◽  
A. Shavorskiy ◽  
R. A. Bennett ◽  
G. Held ◽  
...  
Keyword(s):  
Phase Separation ◽  
Crystallite Growth ◽  
Early Stages

Phase separation during the early stages of ordering in Mi3Mo

1988 ◽  
Vol 36 (2) ◽  
pp. 413-424 ◽  
Author(s):  
U.D. Kulkarni ◽  
S. Banerjee
Keyword(s):  
Phase Separation ◽  
Early Stages

Reverseα–α´ phase separation in Fe-20Cr-6Al alloy

2013 ◽  
Vol 93 (14) ◽  
pp. 1640-1651 ◽  
Author(s):  
C. Capdevila ◽  
M.K. Miller ◽  
F.A. López ◽  
G. Pimentel ◽  
J. Chao
Keyword(s):  
Phase Separation ◽  
Α Phase

Viscoelastic Effects on the Early Stages of Phase Separation in Polymer Blends

1997 ◽  
Vol 30 (15) ◽  
pp. 4459-4463 ◽  
Author(s):  
N. Clarke ◽  
T. C. B. McLeish ◽  
S. Pavawongsak ◽  
J. S. Higgins
Keyword(s):  
Phase Separation ◽  
Polymer Blends ◽  
Early Stages ◽  
Viscoelastic Effects

The Measurement of Composition During the Early Stages of the Spinodal Decomposition of Fe-Cr Alloys

1990 ◽  
Vol 186 ◽  
Author(s):  
M.G. Hetherington ◽  
J.M. Hyde ◽  
M.K. Miller
Keyword(s):  
Monte Carlo ◽  
Phase Separation ◽  
Spinodal Decomposition ◽  
Atom Probe ◽  
Statistical Techniques ◽  
Fine Scale ◽  
Monte Carlo Calculations ◽  
Early Stages ◽  
Non Linear

AbstractThe properties of many advanced alloys are derived from extremely fine-scale microstructures. This poses interesting questions about the measurement of composition on this scale. The phase separation of model Fe-Cr alloys has been been studied with the atom-probe. Statistical techniques have been used to estimate the composition and compare the results with the predictions of linear and non-linear theories of spinodal decomposition and the distributions obtained from Monte-Carlo calculations.

scholarly journals Revealing the early stages of carbamazepine crystallization by cryoTEM and 3D electron diffraction

IUCrJ ◽  
2021 ◽  
Vol 8 (6) ◽  
Author(s):  
Edward T. Broadhurst ◽  
Hongyi Xu ◽  
Simon Parsons ◽  
Fabio Nudelman
Keyword(s):  
Phase Separation ◽  
Electron Diffraction ◽  
Early Stage ◽  
Active Pharmaceutical Ingredient ◽  
Time Resolved ◽  
Carbamazepine Dihydrate ◽  
Early Stages ◽  
3D Electron

Time-resolved carbamazepine crystallization from wet ethanol has been monitored using a combination of cryoTEM and 3D electron diffraction. Carbamazepine is shown to crystallize exclusively as a dihydrate after 180 s. When the timescale was reduced to 30 s, three further polymorphs could be identified. At 20 s, the development of early stage carbamazepine dihydrate was observed through phase separation. This work reveals two possible crystallization pathways present in this active pharmaceutical ingredient.

Microstructure and Densification of Sintered (B+C)-Doped β-Silicon Carbide

1993 ◽  
Vol 327 ◽  
Author(s):  
Wolfgang Braue ◽  
Hans-J. Kleebe ◽  
Carsten Wehling
Keyword(s):  
Silicon Carbide ◽  
Phase Transformation ◽  
Surface Layer ◽  
Preliminary Data ◽  
Combined Approach ◽  
Early Stages ◽  
Α Phase ◽  
Powder Particles

AbstractThe role of boron and carbon during densification of sintered β-SiC was investigated through the combined approach of in-situ dilatometry and CTEM/AEM inspection of TEM-foils referring to well-defined densification events. Preliminary data obtained indicate that in the early stages of densification, boron is not enriched in the continuous carbon-rich surface layer covering the β-SiC powder particles nor does it segregate to internal interfaces in high quantities. Small boron quantities are dissolved in the SiC grains- Simultaneously with the β- to α- phase transformation, decomposition of foam-like B4C aggregates releases small B4C particles, which are bound intragranularly to α-SiC.

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