Introduction
The CALPHAD-type thermodynamic assessments of phase diagrams
have been intensively performed in recent years. In the form of thermodynamic
databases, the results of such assessments are, in general, made available
to the scientific community [1,2]. However, there are still many of the
assessments that have not been incorporated into these databases, nor have
they been made available as database files suitable for use with Thermo-Calc
[1] or PANDAT [2] calculations. Even if alloy systems are already included
in existing databases, it does not mean that these data are exact and not
subject to change. With new experimental data and using different thermodynamic
models, the re-assessment of many alloy systems has been performed. Looking
at the Cu-Zr system in the NIMS thermodynamic database, for example, five
different thermodynamic assessments have been performed in the past, and
two of these are available in commercial databases, while the recent assessments
are not. Thus, one has to wait for the databases to be updated and the
latest assessment becomes available. Another option is for the user to
create a database file. However, this can be a difficult task since to
the user must check the thermodynamic models employed, sublattice configurations,
parameters for pure elements, etc. Clearly, even though this depends on
the alloy system, it is not a simple process and requires knowledge of
commands in the thermodynamic software, thermodynamic models and the CALPHAD-type
assessments. Moreover, in some cases since some papers have misprints of
parameters and free energy expressions, an incorrect phase diagram maybe
obtained even if the correct commands were used to obtain the user database
file. Thus, because of these difficulties some users do not attempt, or
become frustrated with, such thermodynamic calculations. More importantly,
these difficulties may discourage users from using the results of these
assessments.In order to improve on or remove these difficulties the NIMS
thermodynamic database provides user database files and macro files for
use with Thermo-Calc, where these files are ready-made for ease of use
with thermodynamic calculation software. We believe that the NIMS thermodynamic
database will encourage first time users of thermodynamic assessments,
and provide accurate and reliable data to existing users.
Thermodynamic data in the NIMS thermodynamic database
The NIMS thermodynamic database consists of the TDB(Thermodynamic
Database) file and the TCM (Thermo-Calc Macro) file. One can use the TDB
file on Thermo-Calc [1] or PANDAT [2], while the TCM file is only for Thermo-Calc
since it is a macro file for Thermo-Calc. From the TCM file Thermo-Calc
automatically calculates the phase diagram and certain thermodynamic quantities.
The TDB/TCM files have been tested on Thermo-Calc Version P, and PANDAT
Version 4.0. Users should note that for different versions when the TDB/TCM
files produce errors please check the commands used in the files and change
the syntax to match your version. If you have any questions, or there are
misprints/errors found in these files, please contact the webmaster.
Parameter corrections and differences
In some cases, even if you create the TDB file correctly as
indicated in the paper where the parameters are taken from, phase diagrams
shown in the paper can not be reproduced. This is, in most cases, due to
misprints of parameters. We have attempted to correct all such errors in
the TDB/TCM files given in this database, and comments are given in the
Parameter Correction and Differences file. In addition to the results of
the thermodynamic assessments, a list of important papers (experimental
works and other assessments) for the alloy system is provided in the article
section.
References
[1] Thermo-Calc Software, http://www.thermocalc.se/
[2] PANDAT, http://www.materials-design.co.jp/
How to find the data?
How to use TDB/TCM files in Thermo-Calc Classic / PANDAT
Who we are.
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