Oxidation behavior of ODS alloy MA 6000

MA 6000 is a mechanically alloyed Ni-base ODS alloy. Excellent high-temperature strength makes it a strong candidate for application in high-temperature industrial processes. In order to assess its usefulness for high-temperature structural components, in-depth knowledge of its oxidation behavior, particularly long-term exposure, is necessary. The present work deals with studies of the cyclic and isothermal oxidation of MA 6000 in the temperature range 900-1050 degrees C, with emphasis at 1050 degrees C. A few complementary studies have been carried out on the oxide integrity under creep conditions for exposure times of up to 11,000 hr. The results have shown that oxidation of MA 6000 involves rather complex mechanisms and alterations of the oxidation behavior still occur after long-term exposure. Excellent oxidation resistance is based on the formation of an internal continuous Al2O3 layer.