The aim of this work concerns comparison of phase equilibria and kinetics between Pt and Ru in diffusion barriers for gas turbine engines. Ru is believed to be suitable for these applications since it forms an aluminide similar to NiAl, but with a higher melting point and higher ductility at low temperatures. Moreover, Ru is much less expensive than Pt.
The Ni-Al-Ru and the Ni-Al-Pt phase diagram are beeing assessed using the CALPHAD technique. Mobilities of Ru in fcc-Ru and fcc-Ni, and of Ni in hcp-Ru have been optimized using a newly developed method which uses the MATLAB TC-API to optimize the mobilities directly from concentration profiles.