| 1. |
- Strandlund, Henrik, et al.
(author)
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Diffusion process simulations - an overview of different approaches
- 2004
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In: Diffusion and defect data, solid state data. Part A, Defect and diffusion forum. - 1012-0386 .- 1662-9507. ; 233, s. 97-113
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Journal article (peer-reviewed)abstract
- Some different approaches to diffusion process simulations are briefly presented. Their varying areas of applicability are discussed. Example simulations using the phase-field method, the DICTRA software, and random-walk based approaches are presented.
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| 2. |
- Strandlund, Henrik, et al.
(author)
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Prediction of Kirkendall shift and porosity in binary and ternary diffusion couples
- 2004
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In: Acta Materialia. - : Elsevier BV. - 1359-6454 .- 1873-2453. ; 52:15, s. 4695-4703
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Journal article (peer-reviewed)abstract
- Computer simulations are applied to simulate the Kirkendall shift and porosity in binary and ternary alloys. Three different computational methods, based on different assumptions, are used together with assessed thermodynamic and kinetic data. The simulation results show good agreement compared with experimental data.
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| 3. |
- Strandlund, Henrik, et al.
(author)
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Simulation of diffusion by direct solution in the lattice-fixed frame of reference
- 2006
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In: Metallurgical and Materials Transactions. A. - : Springer Science and Business Media LLC. - 1073-5623 .- 1543-1940. ; 37A:6, s. 1785-1789
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Journal article (peer-reviewed)abstract
- A new simulation method for bulk diffusion that automatically takes the Kirkendall effect into account is presented. Example simulations are presented and compared with experimental data and DICTRA simulations.
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| 4. |
- Chen, Q, et al.
(author)
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Thermo-Calc program interfaces and their applications - Direct insertion of thermodynamic and kinetic data into modeling of materials processing, structure, and property
- 2005
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In: PRICM 5. - ZURICH-UETIKON : TRANS TECH PUBLICATIONS LTD. - 0878499601 ; , s. 3145-3148
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Conference paper (peer-reviewed)abstract
- Thermodynamic and kinetic data are generally essential for quantitative modeling of materials processing, structure, and property. Thermo-Calc program interfaces, including TQ, TC-API, and TC MATLAB Toolbox, provides a hierarchy of APIs for application programmers to access thermodynamic and kinetic data via the kernel of Thermo-Calc and DICTRA, the most widely used software and database system for multi-component phase equilibrium and phase transformation calculations. With these program interfaces, variation of thermodynamic and kinetic properties can be directly obtained in real time as the local temperature, pressure, or composition changes. The structure and usage of the Thermo-Calc program interfaces will be introduced in this article. Successful application examples will be illustrated.
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| 5. |
- Larsson, Henrik, et al.
(author)
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Unified treatment of Kirkendall shift and migration of phase interfaces
- 2006
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In: Acta Materialia. - : Elsevier BV. - 1359-6454 .- 1873-2453. ; 54:4, s. 945-951
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Journal article (peer-reviewed)abstract
- A recent treatment of diffusion in a lattice-fixed frame of reference, which can predict the Kirkendall shift, is modified to be applicable also to the migration of phase interfaces. The net flux across a reference point in the lattice, yielding the Kirkendall shift, as well as the net flux across a phase interface, yielding its migration, are obtained from the same flux equation. Numerical calculations are presented and demonstrate that the method gives expected results. The strength of the method is that it is not based on the assumption of local equilibrium and it is capable of automatically yielding close to local equilibrium conditions except at high supersaturations. There it describes an increasing deviation from local equilibrium as the initial alloy composition is moved inside the one-phase field for the new phase. The interaction of a migrating phase interface and Kirkendall markers is also illustrated.
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| 6. |
- Offerman, S. E., et al.
(author)
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Ferrite formation during slow continuous cooling in steel
- 2007
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In: Fundamentals of Deformation and Annealing. - Stafa : Trans Tech Publications Inc.. - 0878494340 - 9780878494347 ; , s. 357-362
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Conference paper (peer-reviewed)abstract
- Ferrite formation during austenite decomposition in carbon-manganese steel is studied during slow continuous cooling by three-dimensional x-ray diffraction microscopy at a synchrotron source. The ferrite fraction and nucleation rate are measured simultaneously and independently in real time in the bulk of the specimen. Thermodynamic calculations involving both ortho - and para -equilibrium have been performed to determine the driving force for nucleation. From the experiments and thermodynamic calculations the activation energies are estimated for nucleation and the transfer of iron atoms across the interface of the cluster during ferrite nucleation in steel.
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| 7. |
- Strandlund, Henrik, et al.
(author)
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An effective mobility approach to solute drag in computer simulations of migrating grain boundaries
- 2008
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In: Computational materials science. - : Elsevier BV. - 0927-0256 .- 1879-0801. ; 44:2, s. 265-273
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Journal article (peer-reviewed)abstract
- An approach for taking solute drag into account in simulations of grain boundary migration in multicomponent systems in two or three dimensions has been developed. The new method is based on an effective mobility which is a function of the thermodynamic properties in the bulk and the grain boundary and the total driving force. Examples from phase-field simulations in Fe-Ni and Ni-Cr-Fe are presented.
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| 8. |
- Strandlund, Henrik, et al.
(author)
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Computer simulations of solute drag in grain boundary migration and phase transformations
- 2005
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In: Solid-Solid Phase Transformations in Inorganic Material 2005, Vol 2. ; , s. 817-822
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Conference paper (peer-reviewed)abstract
- The effect of alloying elements on migrating interfaces, so-called solute drag, has been studied for many years and different theoretical treatments have been presented. In this work the approach based on the dissipation of Gibbs energy due to diffusion inside the interface, originally introduced by Hillert and Sundman, has been applied and coupled to simulations of grain growth using the phase-field method. In the phase-field simulations an effective mobility, which takes the effect of solute-drag into account, has been formulated and implemented into a phase-field software. The approach is not restricted only to curvature driven grain growth, also recrystallization can be taken into account. In addition, the austenite to ferrite transformation has been studied using a recent coupling between the DICTRA software and the dissipation of Gibbs energy approach.
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| 9. |
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| 10. |
- Strandlund, Henrik
(author)
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High-speed thermodynamic calculations for kinetic simulations
- 2004
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In: Computational materials science. - : Elsevier BV. - 0927-0256 .- 1879-0801. ; 29:2, s. 187-194
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Journal article (peer-reviewed)abstract
- Simulation of phase transformations may be divided into two parts: the simulation of kinetics and the calculation of thermodynamic quantities. A number of softwares for thermodynamic calculations are available and it is thus convenient to use such software to obtain an accurate description of thermodynamic properties and couple them to a software simulating the kinetics. A major problem then is that the computational work to evaluate the thermodynamic quantities is often too heavy unless very simplified thermodynamic models are used. That problem may be solved by calculating the thermodynamic quantities in selected points and time steps only and apply an artificial neural network to obtain the values in all other points. This approach has successfully been applied to diffusion in alloys and has enabled us to incorporate thermodynamic data from the Thermo-Calc software package into simulations of diffusion in a very efficient way.
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