MICROSTRUCTURAL CHARACTERISTICS OF HIGH-TEMPERATURE OXIDATION IN NICKEL-BASE SUPERALLOY

High-temperature oxidation behavior of a nickel-base superalloy is exa mined using optical and scanning electron microscopical techniques, Th e morphology of the oxide layers developed is examined, and EDX microa nalysis reveals diffusion of the elements across the oxide-metal inter face, Evidence of internal oxidation is presented, and the role of str uctural defects is considered, The morphology of the oxide-metal inter face formed in the specimens exposed in steam and air is examined to e lucidate the mechanism of high-temperature oxidation.