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thermodynamic-driving-forces
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On the phase field modeling of crack growth and analytical treatment on the parameters
, Article Continuum Mechanics and Thermodynamics ; 2018 , Pages 1-18 ; 09351175 (ISSN) ; Javanbakht, M ; Jafarzadeh, H ; Sharif University of Technology
Springer New York LLC
2018
Abstract
A thermodynamically consistent phase field model for crack propagation is analyzed. The thermodynamic driving force for the crack propagation is derived based on the laws of thermodynamics. The Helmholtz free energy satisfies the thermodynamic equilibrium and instability conditions for the crack propagation. Analytical solutions for the Ginzburg–Landau equation including the surface profile and the estimation of the kinetic coefficient are found. It is shown how kinetic coefficient affects the local stress field. The local critical stress for the crack propagation is calibrated with the theoretical strength which gives the value of the crack surface width. The finite element method is...
Fast isothermal solidification during transient liquid phase bonding of a nickel alloy using pure copper filler metal: solubility vs diffusivity
, Article Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science ; Volume 50, Issue 5 , 2019 , Pages 2235-2245 ; 10735623 (ISSN) ; Pouranvari, M ; Sharif University of Technology
Springer Boston
2019
Abstract
This investigation aims at understanding the underlying fundamentals of the isothermal solidification phenomenon during the transient liquid phase (TLP) bonding process. The isothermal solidification is governed by solid-state diffusion of the melting point depressant (MPD) into the base material, which, in turn, is controlled by both kinetic and thermodynamic parameters; however, the latter factor is generally ignored. In this work, the competition between kinetics and thermodynamics of diffusion were considered in TLP bonding of a nickel alloy, Monel 400, using two distinct filler metals including pure copper (Cu) and Ni-Si-B filler metal. The joint generated by Ni-Si-B filler metal...
Gaseous reduction of manganese ores: A review and theoretical insight
, Article Mineral Processing and Extractive Metallurgy Review ; Volume 41, Issue 3 , 2020 , Pages 198-215 ; Yoozbashizadeh, H ; Safarian, J ; Sharif University of Technology
Taylor and Francis Inc
2020
Abstract
Gaseous reduction of manganese ores has been studied as it is beneficial for both understanding the common ferromanganese production process and the development of new processes. Thermodynamics, kinetics, and the mechanisms of reduction by methane have been reviewed, supported by thermodynamic calculations from the commercial HSC Chemistry and FactSage software. While there were similarities in reduction process by CO and H2, methane was a more efficient reductant and yielded reduction levels beyond MnO, which was due to the large thermodynamic driving force for carbide formation by metastable methane. The practical aspects of gaseous reduction by methane, such as application of a...
On the phase field modeling of crack growth and analytical treatment on the parameters
, Article Continuum Mechanics and Thermodynamics ; Volume 32, Issue 3 , 2020 , Pages 589-606 ; Javanbakht, M ; Jafarzadeh, H ; Sharif University of Technology
Springer
2020
Abstract
A thermodynamically consistent phase field model for crack propagation is analyzed. The thermodynamic driving force for the crack propagation is derived based on the laws of thermodynamics. The Helmholtz free energy satisfies the thermodynamic equilibrium and instability conditions for the crack propagation. Analytical solutions for the Ginzburg–Landau equation including the surface profile and the estimation of the kinetic coefficient are found. It is shown how kinetic coefficient affects the local stress field. The local critical stress for the crack propagation is calibrated with the theoretical strength which gives the value of the crack surface width. The finite element method is...
Thermodynamic analysis of Ti-Al-C intermetallics formation by mechanical alloying
, Article Journal of Alloys and Compounds ; Volume 576 , 2013 , Pages 317-323 ; 09258388 (ISSN) ; Karimzadeh, F ; Abbasi, M. H ; Sharif University of Technology
2013
Abstract
In the present study the behavior of Ti-Al-C ternary system is investigated during mechanical alloying. The mixture of Ti, Al and C powders was used with initial stoichiometric composition of Ti3AlC2. X-ray diffraction (XRD) was used to characterize the milled powders and a thermodynamic analysis of the process was then carried out using Miedema model. This thermodynamic analysis showed that for all binary Ti-C, Al-C, Ti-Al systems and ternary Ti-Al-C systems, among all compositions, the thermodynamic driving force for intermetallic phase formation is much greater when compared with the formation of solid solutions or amorphous phases. Finally the reactions that are feasible to occur during...