1) Environment and Energy Materials Division, National Institute for Materials Science
2) Department of Metallurgy and Ceramics Science, Tokyo Institute of Technology
3) Department of Materials, Physics and Energy Engineering, Nagoya University
4) Fracture and Reliability Research Institute, School of Engineering, Tohoku University
*: Corresponding author, abe.taichi@nims.go.jp
Abstract:
The activity of CALPHAD (CALculation of PHAse Diagrams) has been started in the late 1960’s [1]. Based on the CALPHAD approach, many of phase diagrams have been critically assessed where the Gibbs energy of both stable and metastable phases were optimized to experimental and theoretical thermodynamic quantities such as enthalpies and phase equilibria. Consequently, there are many thermodynamic databases available for e.g. Ni-based, Fe-based alloys. Since these databases can be applied for estimating phase equilibria in multi-component systems (commercial alloys), which consist of more than 10 elements. It is becoming a powerful tool for alloy developments and process optimizations. For alloy systems with lanthanide elements, there is no thermodynamic database available for public, since thermodynamic quantities are difficult to be measured; it is mainly due to their strong affinity to Oxygen. Correcting data in literature and thermodynamic quantities obtained in the ESICMM project, we are constructing a database for Nd-based permanent magnets.
Since the present database [2] is still a preliminary version, applicable composition ranges are very limited upto several at.% of additives, and some of ternary mixings into binary compounds are not included. Oxygen and lanthanide elements other than Nd will be included in the future updates. This database is written in a TDB (Thermodynamic DataBase) format, which are for many of thermodynamic software packages such as CaTCalc, PANDAT, and Thermo-Calc.
Some results of the thermodynamic calculations using our database will be shown and discussed in this presentation.
Since the present database [2] is still a preliminary version, applicable composition ranges are very limited upto several at.% of additives, and some of ternary mixings into binary compounds are not included. Oxygen and lanthanide elements other than Nd will be included in the future updates. This database is written in a TDB (Thermodynamic DataBase) format, which are for many of thermodynamic software packages such as CaTCalc, PANDAT, and Thermo-Calc.
Some results of the thermodynamic calculations using our database will be shown and discussed in this presentation.
[1] H.L.Lukas, S.G.Fries, B.Sundman: Computational thermodynamics, Cambridge, (2007).
[2] NIMS Computational phase diagram database: http://cpddb.nims.go.jp/
[2] NIMS Computational phase diagram database: http://cpddb.nims.go.jp/
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