The isothermal and cyclic oxidation behavior of PtAl and PtAl + Zr was stud
ied followed by postoxidation microstructural and microchemical analyses. T
heir isothermal oxidation performance at 1200 degrees C was similar to that
of NiAl and NiAl + Zr. In short (1-h) cycles, the cyclic oxidation resista
nce of undoped PtAl was found to be substantially better than NiAl. However
, with longer (100-h) cycles, little improvement in the metal consumption r
ate was observed relative to NiAl. The addition of Zr to PtAl significantly
improved cyclic oxidation performance in both short- and long-cycle tests.
Spatially resolved energy dispersive spectroscopy indicated Zr segregation
to both the metal-oxide interface and Al2O3 grain boundaries.