of phase boundary compositions in multicomponent, multiphase systems
for a fixed
temperature and pressure
this application might be used for calculating the solubilities of
elements in a phase.
After having loaded the appropriate data into MTDATA and selected the
phase classifications as required, this application is
initiated by entering "transn_p.mac". Prompts are provided to help the
user to decide what to type in next.
first prompt asks for the maximum number of phase boundaries to be
found. In order to find them all a relatively high number eg 20 should
it is possible to do a calculation, it is necessary to set the
temperature required (using the set command) and the
compositions limits for the scan. The composition limits are defined
through use of composition groups, again using the
set command. eg
set "start" = 0.8 0.0001 0.05
0.15 ! set
"final" = 0.8 0.05 0.0001 0.15 !
compositions could be defined either in terms of moles or masses, again
by using the set command. eg
set w = 1 !
set n = 1 !
the "range" command is used to confirm these groups and specify the
tolerance in composition that we wish to use (typically 0.001). eg
range "start" "final" 0.001 !
computer output (following the entry of "compute !") for this
application consists of:
initial composition (in terms of moles and masses of the components
depending on how it was defined)
The set of phases stable in the particular composition range
The composition of any phase boundaries encountered defined in terms of
the proportion of the composition range scanned
and in terms of the actual
component mole or mass fractions
The final composition defined for the calculations
output might look something like this:
Number of phase boundaries requested 20
0.80000000 1.000000E-04 5.000000E-02 0.15000000
GRAPHITE BCC_A2 M23C6
0.80000000 2.877427E-02 2.132573E-02 0.15000000
GRAPHITE BCC_A2 M7C3 M23C6
0.80000000 4.953120E-02 5.688011E-02 0.15000000
GRAPHITE BCC_A2 M7C3
0.80000000 5.000000E-02 1.000000E-04 0.15000000