Over the last decades, computational thermodynamic programs like e.g. Thermo-Calc or JMatPro® have established themselves as powerful tools for theoretical alloy design and improvement, but also for process parameter optimization and development for industrial applications (e.g. heat treatment, high temperature brazing).
The aim of the present investigation was the experimental validation of thermodynamic equilibrium calculations using the TCNi6 database and Thermo-Calc 2015b for the design of an advanced NiCrAlY coating alloy applied in the hot gas section of stationary gas turbines. Thermodynamic equilibrium calculations, performed for different Ni-base coating alloys, were compared to experimental data derived from dilatometry, scanning electron microscopy, energy dispersive X-ray spectroscopy, standard X-ray diffraction and in-situ high temperature X-ray diffraction.
In general, a good agreement between calculated and measured data for the evolution of α-(Cr), β-(NiAl) and γ’-(Ni3Al) precipitates in the γ (Ni, solid solution) matrix was found. The potential of computational thermodynamic calculations for the development of multi-component alloys was shown and could be verified for the investigated materials.