Investigation on Oxidation and Interdiffusion in the Systems of Aluminiferous Coatings and Superalloys

A novel model for coating design was proposed in this research, by considering both oxidation property and interdiffusion effect, corresponding to two factors of the Cr:Al activity ratio and the potential of Al, respectively. To verify this model, oxidation tests of coated superalloys were performed at 1000 ° C for up to 5000 h. The test results indicated a strong positive correlation between GPDZ and Al potential and a clear negative correlation between oxidation kinetics parameter k_p and Cr:Al activity ratio. Our research opened up new ideas for the coating design.