The high temperature oxidation of two B2-Fe40Al Iron Aluminides has been studied in isothermal and cyclic conditions in the range 700°C to 1100°C and compared with a FeCrAlY alloy. One of the aluminides was prepared by mechanical alloying with the addition of an Y2O3-dispersion that conferred to it improved mechanical properties. No significance differences in the isothermal oxidation of the aluminides have been observed due to the presence of the Y2O3. Both aluminides presented higher oxidation rates than the FeCrAlY alloy at 758° and 858°C but lower rates at 1118°C. The tests carried out under thermal cycling (100 1-hour cycles: 40 minutes at 900°C plus 20 minutes at room temperature) showed that the FeCrAlY alloy presented a lower weight increase than both Iron aluminides. Scanning electron microscopy observations revealed a similar acicular morphology of the thin oxide layer formed on the aluminides. The oxide grown on the FeCrAlY alloy presented nodule formation.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Metals and Alloys