Phase Diagrams 
& Computational Thermodynamics

DTA Simulation

Calculation of DTA Curve for Arbitrary Enthalpy vs. T Data Input
Using Model of W.J. Boettinger and U. R. Kattner
and Notebook by K.-W. Moon

Introduction

This Mathematica (Version 4.1) notebook file is used to predict Differential Thermal Analysis Curves for a user-specified sample enthalpy - temperture relation and for a user-specified set of  instrument parameters. Its primary use is to provide DTA users with information on what to expect from DTA curves under known conditions so that real DTA data can be more easily interpreted.
The notebook follows the model developed by W.J. Boettinger and U. R. Kattner (Metall. Mater. Trans. A, Vol. 33A, No. 6, (2002) pp. 1779) The instrument parameters are time constants, heating rate, crucible thermal properties and sample mass.  The instrument  time constants of this example notebook are determined from experiments on the melting of pure Ni for a  Perkin-Elmer DTA1700. (The user should determine time constants and crucible thermal properties appropriate to his/her particular instrument.) The enthalpy-temperature data used for this example are obtained by thermodynamic calculation and stored simply as two columns (temperature, enthalpy) in a ASCII file that is read by the notebook script.   Two enthalpy files are available for Scheil and lever solidification of UDIMET 700.  The calculations were carried out with the NIST solidification programs and Thermotech's Ni-Data database (http://www.thermotech.co.uk/databases.html).

Disclaimer: Commercial equipment and materials are identified in orer to adequately specify certain procedures.  In no case does such identification imply recommendation or endorsement by the National Institute of Standards and Technology, nor does it imply that the materials or equipment identified are necessarily the best available for the purpose.