of primary phase fields and liquids valley for a ternary system at a
application is used for the calculation of liquidus projections eg
liquidus valleys and primary phase fields
for ternary systems at a fixed pressure.
Graphical output is produced as the calculations proceed showing the
liquidus valley as calculated by MTDATA.
asking for the liquidus valley to be calculated it is necessary to
datafile for the ternary system, to classify any phases required to be
absent or identified as
giving rise to miscibility gaps and to specify the pressure. All this
can be set up using the normal APPLICATION commands within MTDATA.
Also it is necessary to identify the liquid phase. eg:
set user_v(k_liquid) 3 !
to define the range
of temperatures to be covered by the scan for the liquidus valleys
range t 500 1200 1 !
third value here represents the step size in temperature when following
the valley. The best value to choose here
depends on how flat the liquidus surface is likely to be. For a very
steep liquidus surface a value such as 20 might
be appropriate, while for a flat surface, a value of 1 might be best.
start point for the calculations can be selected using the graphics
cursor interactively or, before the
"compute" command is issued, by setting the composition using the "set"
command. Following the calculations
the diagram may be labelled: entry of "l" (twice) or clicking the right
mouse button in WinMT, will show the name of the phase in this region
precipitating first from the liquid (the primary phase field). Entry of
"t" (twice) near where three liquidus valley lines join, will provide
the value of the temperature of
the invariant reaction eg a eutectic, peritectic or transition
projections may also be calculated using other MTDATA applications ie.
LIQSECT and LIQCONT. These
use different ways to delineate the liquidus valley are not limited to