Abstract
A study on the anisotropic oxidation resistance in a Ni-base single crystal superalloy was investigated at 1000 degrees C. Overall, the specimens with (100) face showed a higher oxidation rate compared with the specimens with (110) face. These results showed that the anisotropic oxidation resistance occurred in this study. The formation of the oxide scales on the surfaces of superalloy produces a large number of short-circuit diffusion paths. These short-circuit diffusion paths were influenced by the crystallographic orientations during oxidation which finally results in various oxidation rates as a function of the specimen orientations. This anisotropic oxidation resistance can be triggered by the different structure of gamma/gamma' interface acting as rapid diffusion paths for cations diffusion during oxidation in the superalloy. Furthermore, the difference in NiO grain size oxides scale structure and the thickness of oxide scale can be used to clarify the oxidation anisotropy in a Ni-base single crystal superalloy.