The creep behaviour of platinum-based γ/γ′ analogues of nickel-based superalloys at 1300 °C

The creep behaviour of several ternary Pt–Al–Z alloys (Z=Cr, Ru and Ir) at 1300 °C was investigated by conducting stress–rupture tests. The ternary elements were selected either to stabilise the L12 form of Pt3Al, or as solid–solution strengthening elements for the Pt matrix. The effects of ternary alloying elements on the high-temperature mechanical behaviour of Pt-based (Pt)/Pt3Al alloys are critical. The ferritic ODS alloy PM2000 was used as a benchmark. The tested samples were examined using scanning electron microscopy. The results are very promising, particularly those for the Pt86:Al10:Cr4 alloy, which showed very good stress–rupture strength. The Pt–Al–Z alloys had lower strength than PM2000, but far superior ductility.