Oxidation of ruthenium aluminide-based alloys: The role of microstructure and platinum additions

The cyclic oxidation behavior of six RuAl-based alloys was studied in air over the temperature range of 1000–1300 °C. Oxidation kinetics were influenced by microstructure as well as the addition of platinum. Single phase RuAl-based alloys formed a layered oxide structure during oxidation. The presence of the δ-Ru-rich eutectic along grain boundaries strongly accelerated the oxidation process. A single phase Pt-containing RuAl-based alloy exhibited the highest oxidation resistance.