| 1. |
- Arvhult, Carl-Magnus, et al.
(författare)
-
Experimental Phase Diagram Study of the Fe-Ni-Te System
- 2019
-
Ingår i: JOURNAL OF PHASE EQUILIBRIA AND DIFFUSION. - : Springer Nature. - 1547-7037 .- 1863-7345. ; 40:4, s. 610-622
-
Tidskriftsartikel (refereegranskat)abstract
- Fe-Ni-Te alloys have been experimentally studied using isothermal heat treatments with SEM-EDS and WDS, XRD, and DTA in order to add phase diagram data for a thermodynamic assessment. This is for the application of fission product-induced corrosion of the stainless steel cladding of nuclear fuel pins, where Te is a key element. Phase diagram data are presented at phase. SEM images show unidentified precipitates in several samples.
|
|
| 2. |
- Bigdeli, Sedigheh, et al.
(författare)
-
A New Description of Pure C in Developing the Third Generation of Calphad Databases
- 2018
-
Ingår i: Journal of Phase Equilibria and Diffusion. - : Springer Nature. - 1547-7037 .- 1863-7345. ; 39:6, s. 832-840
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- In connection to developing the third generation of Calphad databases a new thermodynamic description is presented for unary carbon. Models used in this work have more physical basis and are valid down to 0 K. The anisotropy in graphite, caused by weak Van der Waals inter-plane forces makes it difficult to fit the heat capacity data by a single Einstein tempera-ture for modelling the harmonic vibration of the atoms. By using multiple Einstein temperatures this problem is solved and a good agreement with the experimental data at low temperatures is achieved. Diamond is mod-eled using new models too, and the two-state model is used for modelling the liquid phase.
|
|
| 3. |
- Bigdeli, Sedigheh, 1984, et al.
(författare)
-
Strategies for High-Temperature Corrosion Simulations of Fe-Based Alloys Using the Calphad Approach : Part I
- 2021
-
Ingår i: Journal of Phase Equilibria and Diffusion. - : Springer Nature. - 1547-7037 .- 1863-7345. ; 42:3, s. 403-418
-
Tidskriftsartikel (refereegranskat)abstract
- The environmental degradation of materials at high temperatures limits the useful life of different industrial components and hinders the development of more economical and environmentally friendly processes for the energy production. Despite the importance of this phenomena, a model to predict lifetime of materials that degrade due to high-temperature corrosion has up till now been lacking due to limitations of the computational possibilities and the complex nature of oxidation. In the present work we develop some strategies to model high-temperature corrosion in Fe-based alloys using the Calphad (Calculation of Phase Diagrams) approach. It is proposed that kinetic-based simulations for oxidation of Al and Cr can accurately represent the lifetime of the protective layers in FeCrAl and FeCr alloys at different temperatures in air. The oxide systems are in addition investigated by equilibrium calculations. The corrosion mechanisms of FeCr and FeCrAl alloys are discussed based on theoretical and experimental knowledge.
|
|
| 4. |
- Chen, Qing, et al.
(författare)
-
On Negative Diagonal Elements in the Diffusion Coefficient Matrix of Multicomponent Systems
- 2018
-
Ingår i: JOURNAL OF PHASE EQUILIBRIA AND DIFFUSION. - : Springer. - 1547-7037 .- 1863-7345. ; 39:5, s. 592-596
-
Tidskriftsartikel (refereegranskat)abstract
- In multicomponent systems the diffusion coefficient turns into a matrix. The diagonal elements represent diffusion of a species caused by its own concentration gradient. In a thermodynamically stable binary alloy it is easy to see that this diagonal element must be positive but in a multicomponent system it is less obvious. The sign of the diagonal elements in the general case is discussed in this report. It is shown that the sign of an individual diagonal element has no physical meaning but can be changed by changing the dependent concentration variable. Only the sum of all the diagonal elements need to be positive in a stable system.
|
|
| 5. |
- Dilner, David, et al.
(författare)
-
Thermodynamic Assessment of the Fe-Ca-S, Fe-Mg-O and Fe-Mg-S Systems
- 2016
-
Ingår i: Journal of Phase Equilibria and Diffusion. - : Springer-Verlag New York. - 1547-7037 .- 1863-7345. ; , s. 1-16
-
Tidskriftsartikel (refereegranskat)abstract
- Thermodynamic descriptions of the Fe-Mg-O, Fe-Ca-S and Fe-Mg-S systems are all important in order to perform thermodynamic calculations related to the steelmaking process. The experimental information of many sulphur-containing systems, including Fe-Ca-S and Fe-Mg-S, is lacking and they are here thus approximated to behave similarly to the corresponding oxygen systems. This study presents a description of the Fe-Mg-O system in good agreement with experimental information. Additionally, descriptions of the Fe-Ca-S and Fe-Mg-S systems are presented. These descriptions may be reasonable estimations considering the lack of experimental information.
|
|
| 6. |
- Dyal Ukabhai, K., et al.
(författare)
-
Formation of Ti2Cu in Ti-Cu Alloys
- 2022
-
Ingår i: JOURNAL OF PHASE EQUILIBRIA AND DIFFUSION. - : Springer Nature. - 1547-7037 .- 1863-7345. ; 43:3, s. 332-344
-
Tidskriftsartikel (refereegranskat)abstract
- One of the major issues with dental implants is failure due to bacterial infection, and additions of copper are known to improve the antimicrobial properties of Ti alloys. There are inconsistencies in the Ti rich area of the Cu-Ti binary phase diagram, hence the need to find out if Ti2Cu or Ti3Cu is formed, and to identify the type of formation of Ti2Cu. Four alloys: 20, 33, 40 and 50 Cu (mass%) were produced by arc melting and studied using SEM, XRD and DSC. The reactions were derived, and the temperatures of the reactions were determined by DSC. The formation of Ti2Cu is congruent, and no Ti3Cu was found.
|
|
| 7. |
- He, Zhangting, et al.
(författare)
-
A third generation Calphad description of Fe: revisions of fcc, hcp and liquid
- 2022
-
Ingår i: Journal of Phase equilibria and Diffusion. - : Springer Science and Business Media LLC. - 1547-7037 .- 1863-7345.
-
Tidskriftsartikel (refereegranskat)abstract
- The thermodynamic description of pure Fe was re-assessed using updated third generation Calphad models and taking into account the most recent theoretical data. In the present re-assessment, a critical evaluation was performed for the magnetic properties of the fcc and hcp phases yielding different descriptions from those accepted in the SGTE database. The selected magnetic properties enable us to model the thermodynamic properties of fcc satisfactorily without using the magnetic two-state model. A new method was applied to extrapolate the thermodynamic data for the solid phases, i.e. a single Gibbs energy expression is used for the entire temperature range for the bcc, fcc and hcp phases. The description of the liquid phase was re-evaluated following a recent suggestion on estimating the electronic heat capacity coefficient for the liquid phase. Overall, the present Calphad description can reproduce the selected experimental and theoretical data well.
|
|
| 8. |
- Höglund, Lars, et al.
(författare)
-
Simulation of Carbon Diffusion in Steel Driven by a Temperature Gradient
- 2010
-
Ingår i: Journal of Phase Equilibria and Diffusion. - : Springer Science and Business Media LLC. - 1547-7037 .- 1863-7345. ; 31:3, s. 212-215
-
Tidskriftsartikel (refereegranskat)abstract
- The basis of thermomigration in multicomponent alloys is summarized, and the general equations are given and implemented in the DICTRA software. Experimental information from Okafor et al. is analyzed with the new simulations and it is concluded that steady- state conditions was not established during their experiment. A heat of transport Q(C)* = -44000 J/mol, almost four times larger than the value given by Okafor et al., was found to give a satisfactory representation of the experimental information.
|
|
| 9. |
- Kjellqvist, Lina, 1979-, et al.
(författare)
-
Thermodynamic assessment of the Fe-Mn-O system
- 2010
-
Ingår i: Journal of Phase Equilibria and Diffusion. - : Springer US. - 1547-7037 .- 1863-7345. ; 31:2, s. 113-134
-
Tidskriftsartikel (refereegranskat)abstract
- The C-Cr-Fe-Ni-O system has recently been studied with the intention to thermodynamically describe the influence of oxygen on high alloyed steels. In this study the ternary Fe-Mn-O system is assessed and part of the binary Mn-O system is reassessed. α- and β-hausmannite (Mn3O4) were earlier described as stoichiometric phases, but are here described using the compound energy formalism with a four sublattice model to be consistent with the preceding study of the Cr-Fe-Ni-O spinel. The liquid phase is assessed using the ionic two-sublattice model. Good agreement between calculated and experimental values is achieved.
|
|
| 10. |
- Li, Zhou, 1987-, et al.
(författare)
-
Thermodynamic Modeling of Pure Co Accounting Two Magnetic States for the Fcc Phase
- 2018
-
Ingår i: JOURNAL OF PHASE EQUILIBRIA AND DIFFUSION. - : Springer. - 1547-7037 .- 1863-7345. ; 39:5, s. 502-509
-
Tidskriftsartikel (refereegranskat)abstract
- The thermodynamic functions of the pure Co were assessed using CALPAHD method for the third generation thermodynamic databases. To model the magnetic properties of the cobalt, a two-state magnetic model was accounted for the fcc phase. Calculated results were compared with the experimental information and a good fit to the experimental data was achieved.
|
|
