Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Theoretical modeling of molar volume and thermal expansion
KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.ORCID iD: 0000-0001-5031-919X
KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
2005 (English)In: Acta Materialia, ISSN 1359-6454, E-ISSN 1873-2453, Vol. 53, no 8, 2259-2272 p.Article in journal (Refereed) Published
Abstract [en]

The molar volumes and thermal expansions of transition cubic metals were studied by means of the Calphad approach and the Debye-Gruneisen model. Experimental data were collected and assessed using Calphad procedures, and consistent results were obtained which give the best description of all experimental data. In order to put the prediction of the thermodynamic properties of metastable phases on a sound physical basis, the Debye-Gruneisen model was chosen to account for the vibrational contribution and calculate the coefficients of linear thermal expansion (CLEs) of stable cubic metals. Two approximations for Gruneisen parameter gamma, i.e. Slater ' s and Dugdale and MacDonald ' s expressions were adopted. A modified calculation scheme, first proposed by Wang et al., was derived in a straightforward way and used to evaluate the Debye temperature from ab initio electronic total-energy calculations at T = 0 K. The thermal electronic contribution to CLE was also evaluated from the electronic density of states. The calculated total CLEs were compared with those from the Calphad assessments. A satisfactory agreement is reached.

Place, publisher, year, edition, pages
2005. Vol. 53, no 8, 2259-2272 p.
Keyword [en]
molar volume, thermal expansion, ab initio calculations, Debye-Gruneisen model, calphad
National Category
Materials Engineering
Identifiers
URN: urn:nbn:se:kth:diva-5243DOI: 10.1016/j.actamat.2005.01.049ISI: 000228818600007Scopus ID: 2-s2.0-16344390584OAI: oai:DiVA.org:kth-5243DiVA: diva2:8127
Note
QC 20101004Available from: 2005-06-01 Created: 2005-06-01 Last updated: 2017-12-04Bibliographically approved
In thesis
1. Theoretical modeling of molar volume and thermal expansion
Open this publication in new window or tab >>Theoretical modeling of molar volume and thermal expansion
2005 (English)Doctoral thesis, comprehensive summary (Other scientific)
Abstract [en]

Combination of the Calphad method and theoretical calculations provides new possibilities for the study of materials science. This work is a part of the efforts within the CCT project (Centre of Computational Thermodynamics) to combine these methods to facilitate modeling and to extend the thermodynamic databases with critically assessed volume data. In this work, the theoretical calculations refer to first-principles and Debye-Grüneisen calculations. The first-principles (i.e. ab initio) electronic structure calculations, based on the Density- Functional Theory (DFT), are capable of predicting various physical properties at 0 K, such as formation energy, volume and bulk modulus. The ab initio simulation software, VASP, was used to calculate the binding curves (i.e. equation of state at 0 K) of metallic elements, cubic carbides and nitrides. From the binding curves, the equilibrium volumes at 0 K were calculated for several metastable structures as well as stable structures. The vibrational contribution to the free energy was calculated using the Debye-Grüneisen model combined with first-principles calculations. Two different approximations for the Grüneisen parameter, γ, were used in the Debye-Grüneisen model, i.e. Slater’s and Dugdale-MacDonald’s expressions. The thermal electronic contribution was evaluated from the calculated electronic density of states. The calculated thermal expansivities for metallic elements, cubic carbides and nitrides were compared with Calphad assessments. It was found that the experimental data are within the limits of the calculations using the two approximations for γ. By fitting experimental heat capacity and thermal expansivity around Debye temperatures, we obtained optimal Poisson’s ratio values and used them to evaluate Young’s and Shear moduli. In order to reach a reasonable agreement with the experiments, it is necessary to use the logarithmic averaged mass of the constitutional atoms. The agreements between the calculations and experiments are generally better for bulk modulus and Young’s modulus than that for shear modulus. A new model describing thermodynamic properties at high pressures was implemented in Thermo-Calc. The model is based on an empirical relation between volume and isothermal bulk modulus. Pure Fe and solid MgO were assessed using this model. Solution phases will be considered in a future work to check the model for compositional dependence.

Keyword
Materials science, first-principles calculations, ab initio, Calphad, Debye-Grüneisen model, thermodynamic properties, elastic modulus, volume, thermal expansivity, pressure, Thermo-Calc, VASP, element, carbide, nitride, Materialvetenskap
National Category
Materials Engineering
Identifiers
urn:nbn:se:kth:diva-252 (URN)91-7178-086-0 (ISBN)
Public defence
2005-06-07, Salongen, KTHB, Osquars backe 31, Stockholm, 10:00
Opponent
Supervisors
Available from: 2005-06-01 Created: 2005-06-01 Last updated: 2012-03-22

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Authority records BETA

Selleby, Malin

Search in DiVA

By author/editor
Lu, Xiao-GangSelleby, MalinSundman, Bo
By organisation
Materials Science and Engineering
In the same journal
Acta Materialia
Materials Engineering

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 257 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf