title: The OpenCalphad thermodynamic software interface.
abstract: Thermodynamic data are needed for all kinds of simulations of materials processes. Thermodynamics determines the set of stable phases and also provides chemical potentials, compositions and driving forces for nucleation of new phases and phase transformations. Software to simulate materials properties needs accurate and consistent thermodynamic data to predict metastable states that occur during phase transformations. Due to long calculation times thermodynamic data are frequently pre-calculated into "lookup tables" to speed up calculations. This creates additional uncertainties as data must be interpolated or extrapolated and conditions may differ from those assumed for creating the lookup table. Speed and accuracy requires that thermodynamic software is fully parallelized and the Open-Calphad (OC) software is the first thermodynamic software supporting this feature. This paper gives a brief introduction to computational thermodynamics and introduces the basic features of the OC software and presents four different application examples to demonstrate its versatility.
authors.affiliation: INSTN, CEA Saclay, France.
authors.forename: Bo
authors.initials: B
authors.lastname: Sundman
authors.affiliation: National Institute of Standards and Technology, Gaithersburg, MD, USA.
authors.forename: Ursula R
authors.initials: UR
authors.lastname: Kattner
authors.affiliation: Constellium Technology Center, CS 10027, 38341 Voreppe Cedex, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Sigli
authors.affiliation: Ruhr University Bochum, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Stratmann
authors.affiliation: CEA, DEN, DTN/SMTA/LPMA Cadarache, F-13108 St Paul-lez-Durance, France.
authors.forename: Romain
authors.initials: R
authors.lastname: Le Tellier
authors.affiliation: SISSA, Trieste, Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Palumbo
authors.affiliation: Ruhr University Bochum, Germany.
authors.forename: Suzana G
authors.initials: SG
authors.lastname: Fries
keywords: CALPHAD; Computational Thermodynamics; Free Software; Parallel Computing; Phase Transformations; Simulations