is a consortium of European and North-American research organisations
working together to develop high-quality thermodynamic
databases for a wide variety of inorganic and metallurgical systems.
has been at the forefront of the broader international effort to unify
thermodynamic data and assessment methods by promoting use of standard
reference data for the elements and binary systems, and generic models
represent the variation in thermodynamic properties with temperature
composition. NPL is a founding member of SGTE.
SGTE data can be obtained via members and their
use on personal computers with commercially available software, to
users to undertake calculations of complex chemical and phase
efficiently and reliably. Members of SGTE have played a principal role
in promoting the concept
of ‘computational thermochemistry’ as a time- and
cost-saving basis for the
control and modelling of various types of materials process. In
such calculations provide crucial process-related information regarding
nature, amounts and distribution of environmentally hazardous
produced during the different processing stages.
SGTE have developed a number of thermodynamic
database for a wide range of technologically important materials. Such
databases contain critically assessed data, a set of model parameters
which describe as accurately as possible experimental thermodynamic and
phase diagram data for binary, ternary systems and higher order
systems. The models are based on physical principles which make it
possible to extrapolate the critically assessed data to commercially
important multi-component systems. Extrapolation from several assessed
lower order systems require that these systems are internally
consistent and this take time and effort to achieve. At present, a
number of commercially interesting as well as scientifically
challenging materials have been collected into databases which are
available and listed below. The SGTE Databases are under continuous
SGTE databases include
The SGTE Pure Substance
Database containing assessed thermochemical
data for about 4000 condensed compounds or gaseous species.
The Unary database
containing assessed thermochemical data
for all stable and many metastable modifications from 298.15 K up to
gaseous state for many elements. These descriptions of the
properties of the elements are used as a basis for all SGTE databases.
Solution database which contains data
for the liquid phase and various crystalline phases of the pure
addition to over 400 binary, ternary and quaternary alloy systems. The
have been derived by a process of critically assessment taking all the
experimental data, eg enthalpies of mixing, partial pressures,
arrests etc and then using them to derive a small number of
representing how the thermodynamic properties of the system change with
temperature and composition.
Thermal Barrier Coating database was developed
in the Max-Planck-Institute Institute for Metal Research in Stuttgart.
covers the system ZrO2-Gd2O3-Y2O3-Al2O3 and is suitable for
calculations between 300 K
and 3000 K, but in particular above 1100 K. Most of the phases stable
in the system are solid solutions described using the compound energy
formalism. The liquid phase was described using the
two-sublattice partially ionic liquid model. Yyttria stabilised
zirconia (YSZ) itself has various industrial applications. For example,
the phase with the fluorite structure is used as a solid electrolyte.
The tetragonal phase with 6-8 wt. % Y2O3
is used as a thermal barrier coating (TBC) on a metal substrate.
Co-doping of the traditional YSZ with Gd enhances the insulating
efficiency of thermal barrier system. A thin layer of alpha-Al2O3
(thermally grown oxide, TGO) forms between metallic bond coat and the
TBC in the process of thermal cycling. Therefore, phase relations in
the ZrO2-Gd2O3-Y2O3-Al2O3 system are important to understand the
interactions between TBC and the TGO, stability issues of TBC materials
and interactions within multilayer TBC.
database for molten salt systems
partly on a compilation of data for Alkali metal halides from Sangster
and Pelton but modified
considerably to present self-consistent modelling of data across
database consists of data for the liquid slag and
for the Al2O3-CaO-FeO-Fe2O3-MgO-SiO2 system.
Recently, data for Na, Cr, Ni, P and have been added and thus allow
sulphide capacities of slags. The liquid slag is described with the
proposed by Kapoor-Frohberg and modified by Gaye. Composition
variations in the
solid oxides have not been taken into account.
semiconductor database contains the 15
possible binary systems between the group III elements Al, Ga and In
and the group V elements P, As and Sb.
metal alloy database contains
thermodynamic parameters for alloys of Ag, Au, Ir,
Os, Pd, Pt, Rh, Ru alloyed amongst themselves and also in alloys with
metals Al, As, Bi, C, Co, Cr, Cu, Fe, Ge, In, Mg,
Ni, Pb, Sb, Si, Sn, Ta, Te, Ti, Tl, Zn, Zr. The database
provides a good starting basis for development of data for higher-order
metal systems. At the same time, the assessed data it contains for the
and ternary sub-systems of Au-Pd-Pt-Sn allow
calculations relevant to dental alloy development.
Nuclear Database has been
generated as part of a much bigger database effort to cover many
aspects related to the field of nuclear reactors. This database is
made for the investigation of in-vessel chemical reactions. The
included in the database are O, U, Zr, Fe, Cr, Ni,
Ar, H. Also included are systems formed among the 6 oxides UO2, ZrO2,
FeO, Fe2O3, Cr2O3, NiO. The database
covers the entire composition range from pure metal to oxide regions
contains critically evaluated thermodynamic parameters for all relevant
multicomponent condensed or gaseous substances and solution phases.
SGTE has also been involved in publication of data
through the Landolt Börnstein series. Two sets of volumes
have been produced so far dealing with:
future set of subvolumes is under way covering specific ternary systems
relevant to technologically important classes of materials.
Substances - Subvolume A: Heat Capacities, Enthalpies, Entropies and
Energies, Phase Transition Data
and Compounds from AgBr to Ba3N2
from BeBr‹g> to ZrCl2‹g>
from CoCl3 to Ge3N4
from HgH‹g> to ZnTe‹g>
Systems - Subvolume B: Phase Diagrams, Phase Transition Data, Integral
Partial Quantities of Alloys
and Binary Systems from Ag-Al to Au-Tl
Systems from B-C to Cr-Zr
Systems from Cs-K to Mg-Zr
Systems from Mn-Mo to Y-Zr