Effect of High Temperature Oxidation on Creep Behavior of Ni-Based Single Crystal Superalloy

Creep tests were performed on nickel-based single crystal superalloy in vacuum after different periods of pre-oxidation treatment. The creep properties were found to be seriously affected by oxidation. After oxidation for a period of time, a heat affected zone (HAZ) formed below the oxide layer. Compared with the substrate, microcracks and defects are easier to form in the heat affected zone. Based on the thickening dynamic model of heat affected layer and crystal plasticity theory, two oxidation-creep models have been established. The initial damage model of pre-oxidation is efficient, which can be predicted the creep life of nickel-based single crystal superalloy under oxidation environment. Another model, the two-phase model, specifically reveals the difference in the failure mechanism of the heat affected zone and the substrate. The research can also be used to promote the disclosure of the creep mechanism and life prediction of multilayer structure materials.