Oxidation behavior of platinum-aluminum alloys and the effect of Zr doping

摘要

The isothermal and cyclic oxidation behavior ofPtAl and PtAl + Zr was studied followed by postoxidationmicrostructural and microchemical analyses. Their isothermaloxidation performance at 1200 beg C was similar to that of NiAland NiAl + Zr. In short (1-h) cycles, the cyclic oxidation resistanceof undoped PtAl was found to be substantially better than NiAl.However, with longer (100-h) cycles, little improvement in themetal consumption rate was observed relative to NiAl. Theaddition of Zr to PtAl significantly improved cyclic oxidationperformance in both short- and long-cycle tests. Spatially resolvedenergy dispersive spectroscopy indicated Zr segregation to both themetal-oxide interface and Al_2O_3 grain boundaries.