Montag, 6. Januar 2014

Eine DTA-Simulation in VBA für den Excel-Export von Pandat2012

Das hier ist ein kleines VBA-Programm, mit dem man das DTA-Signal aus dem Excel-Export der Verfestigungssimulation von Pandat2012 heraus generieren kann. Dabei wird entweder das Scheil- oder das Lever-Verfestigungszenario berücksichtigt. Zur Berechnung wird die Enthalpie Htot verwendet. Viel Spass damit und ich bin gerne offen für Tipps zur Verbesserung. Die mathematische Grundlage für dieses Script wurde veröffentlicht von:

This is a small VBA program, with which you can generate the  DTA-signal from the Excel output of the enthalpy Htot from the solidification simulation of Pandat2012. Pandat generates the data for the Scheil and Lever solidification scenario. Have fun with it and I would like to hear your opinions and hints. The mathematical basis for this script has been published by:

Boettinger, W. J., Kattner, U. R., Moon, K.-W. & Perepezko, J. H. Methods for
Phase Diagram Determinatiom, chap. DTA and Heat-Flux DSC Measurements of
Alloy Melting and Freezing, 151–221 (Elsevier BV, 2007).

See also their online-booklet and their Mathematica program. This macro is in fact just a VBA translation of it. Please read especially what they wrote about the time constants!

Now its easy to do: just get Pandat2012 Demo, take the thermodynamic Database file from NIMS or Calphad journal (look for "assessment" articles there) or the COST507 light metal alloy database, make a solidfication simulation within the desired temperature region with equal minimal and maximal time-steps and without liquidus boundary, generate a "table_output.xls", copy the macro in there et voilà! Remember also to match time-steps and heating rate (6K/min = 0.1K/s). You can change sample mass, crucible mass, the heat capacity of the crucible etc. in the macro to match your wishes.

Since the macro is somewhat long to post, you can download it now here.


Unfortunately, the easy exact fixing of timesteps is not any more available in the new version Pandat2014. This makes the macro harder to use. But not all is lost. Now you have to work with the batchfile from Pandat2014. You have to create the bachfile for the solidification, fix the the timesteps in it with an editor and run the batchfile in Pandat. I will provide an example batch file soon.