scholarly journals Thermodynamic description of metastable fcc/liquid phase equilibria and solidification kinetics in Al-Cu alloys

2022 ◽  
Vol 380 (2217) ◽  
Author(s):  
Yindong Fang ◽  
Peter K. Galenko ◽  
Dongmei Liu ◽  
Klaus Hack ◽  
Markus Rettenmayr ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Phase Equilibria ◽  
High Speed ◽  
Thermodynamic Description ◽  
General Nature ◽  
Miscibility Gap ◽  
Velocity Versus ◽  
Sharp Interface Model ◽  
Cu Alloys ◽  
Fcc Phase

The thermodynamic description of the fcc phase in the Al-Cu system has been revised, allowing for the prediction of metastable fcc/liquid phase equilibria to undercoolings of Δ T  = 421 K below the eutectic temperature. Hypoeutectic Al-Cu alloys that are prone to pronounced microsegregation were solidified containerlessly in electromagnetic levitation. Solidus and liquidus concentrations were experimentally determined from highly undercooled samples employing energy-dispersive X-ray analysis. Solid concentrations at a rapidly propagating solid/liquid interface were additionally calculated using a sharp interface model that considers all undercoolings and is based on solvability theory. Modelling results (front velocity versus undercooling) were also corroborated by in situ observation with a high-speed camera. A newly established thermodynamic description of the fcc phase in Al-Cu is compatible with existing CALPHAD-type databases. Inconsistencies of previous descriptions such as a miscibility gap between Al-fcc and Cu-fcc on the Al-rich side, an unrealistic curvature of the solidus line in the same composition range or an azeotropic point near the melting point of Cu, are amended in the new description. The procedure to establish the description of phase equilibria at high undercoolings can be transferred to other alloy systems and is of a general nature. This article is part of the theme issue 'Transport phenomena in complex systems (part 2)'.

A Thermodynamic description and phase relationships of the FeCr system: Part II the liquid phase and the fcc phase

Calphad ◽  
1987 ◽  
Vol 11 (1) ◽  
pp. 73-81 ◽  
Author(s):  
Jen-Chwen Lin ◽  
Ying-Yu Chuang ◽  
Ker-Chang Hsieh ◽  
Y.Austin Chang
Keyword(s):  
Liquid Phase ◽  
Thermodynamic Description ◽  
System Part ◽  
Fcc Phase ◽  
Cr System ◽  
Phase Relationships

VAN LAAR EQUATION AND UNIFAC TO CORRELATE THE DATA LIQUID PHASE EQUILIBRIA FOR THE EXTRACTION OF PHENOLIC COMPOUNDS FROM MODEL COAL TAR

2016 ◽  
Vol 72 (9) ◽  
Author(s):  
Dewi Selvia Fardhyanti ◽  
Wahyudi B. Sediawan ◽  
Panut Mulyono ◽  
Muslikhin Hidayat
Keyword(s):  
Phenolic Compounds ◽  
Liquid Phase ◽  
Phase Equilibria ◽  
Coal Tar ◽  
Van Laar Equation

Effect of pressure on the solid-liquid phase equilibria in (water + sodium sulfate) system

1992 ◽  
Vol 76 ◽  
pp. 163-173 ◽  
Author(s):  
Y. Tanaka ◽  
S. Hada ◽  
T. Makita ◽  
M. Moritoki
Keyword(s):  
Liquid Phase ◽  
Phase Equilibria ◽  
Sodium Sulfate ◽  
Effect Of Pressure ◽  
Solid Liquid

Solid-liquid Phase Equilibria of U(VI) in NaCl Solutions

1998 ◽  
Vol 62 (2) ◽  
pp. 245-263 ◽  
Author(s):  
P. Dı́az Arocas ◽  
B. Grambow
Keyword(s):  
Liquid Phase ◽  
Phase Equilibria ◽  
Solid Liquid

scholarly journals Thermodynamics and Machine Learning Based Approaches for Vapor–Liquid–Liquid Phase Equilibria in n-Octane/Water, as a Naphtha–Water Surrogate in Water Blends

Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 413
Author(s):  
Sandra Lopez-Zamora ◽  
Jeonghoon Kong ◽  
Salvador Escobedo ◽  
Hugo de Lasa
Keyword(s):  
Machine Learning ◽  
Liquid Phase ◽  
Phase Equilibria ◽  
Aspen Plus ◽  
Phase Region ◽  
Two Phase ◽  
Technical Literature ◽  
Phase Liquid ◽  
Liquid Vapor ◽  
Vapor Liquid

The prediction of phase equilibria for hydrocarbon/water blends in separators, is a subject of considerable importance for chemical processes. Despite its relevance, there are still pending questions. Among them, is the prediction of the correct number of phases. While a stability analysis using the Gibbs Free Energy of mixing and the NRTL model, provide a good understanding with calculation issues, when using HYSYS V9 and Aspen Plus V9 software, this shows that significant phase equilibrium uncertainties still exist. To clarify these matters, n-octane and water blends, are good surrogates of naphtha/water mixtures. Runs were developed in a CREC vapor–liquid (VL_ Cell operated with octane–water mixtures under dynamic conditions and used to establish the two-phase (liquid–vapor) and three phase (liquid–liquid–vapor) domains. Results obtained demonstrate that the two phase region (full solubility in the liquid phase) of n-octane in water at 100 °C is in the 10-4 mol fraction range, and it is larger than the 10-5 mol fraction predicted by Aspen Plus and the 10-7 mol fraction reported in the technical literature. Furthermore, and to provide an effective and accurate method for predicting the number of phases, a machine learning (ML) technique was implemented and successfully demonstrated, in the present study.

Time-Resolved Micro Liquid Desorption Mass Spectrometry: Mechanism, Features, and Kinetic Applications

2006 ◽  
Vol 59 (2) ◽  
pp. 81 ◽  
Author(s):  
Ales Charvat ◽  
Andreas Bógehold ◽  
Bernd Abel
Keyword(s):  
Mass Spectrometry ◽  
Liquid Phase ◽  
High Speed ◽  
High Performance ◽  
Kinetic Studies ◽  
Solution Concentration ◽  
Bulk Water ◽  
Laser Wavelength ◽  
Time Resolved ◽  
Desorption Mass Spectrometry

Liquid water beam desorption mass spectrometry is an intriguing technique to isolate charged molecular aggregates directly from the liquid phase and to analyze them employing sensitive mass spectrometry. The liquid phase in this approach consists of a 10 µm diameter free liquid filament in vacuum which is irradiated by a focussed infrared laser pulse resonant with the OH-stretch vibration of bulk water. Depending upon the laser wavelength, charged (e.g. protonated) macromolecules are isolated from solution through a still poorly characterized mechanism. After the gentle liquid-to-vacuum transfer the low-charge-state aggregates are analyzed using time-of-flight mass spectrometry. A recent variant of the technique uses high performance liquid chromatography valves for local liquid injections of samples in the liquid carrier beam, which enables very low sample consumption and high speed sample analysis. In this review we summarize recent work to characterize the ‘desorption’ or ion isolation mechanism in this type of experiment. A decisive and interesting feature of micro liquid beam desorption mass spectrometry is that — under certain conditions — the gas-phase mass signal for a large number of small as well as supramolecular systems displays a surprisingly linear response on the solution concentration over many orders of magnitude, even for mixtures and complex body fluids. This feature and the all-liquid state nature of the technique makes this technique a solution-type spectroscopy that enables real kinetic studies involving (bio)polymers in solution without the need for internal standards. Two applications of the technique monitoring enzyme digestion of proteins and protein aggregation of an amyloid model system are highlighted, both displaying its potential for monitoring biokinetics in solution.

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