EFFECTS OF Al ADDITION ON THE HIGH TEMPERATURE OXIDATION BEHAVIOR OF CM-247 LC Ni-BASED SUPERALLOY

摘要

The effects of Al addition on the oxidation behavior of CM-247 LC Ni-base superalloy were investigated under high temperature isothermal oxidation test in the dry air. In this study, we explore the difference between the trends of oxidation curves, observe the micro-structure of oxides, gamma matrix and gamma prime precipitate, and further realize the impact of high temperature oxidation behavior and phase stability analysis. Results showed that by adding a small amount of Al, protective oxides could form more easily, and a more regular morphology of γ' in the substrate microstructure could be retained, which in-directly reduced the rate of outward diffusion and prevented further oxidation.