Influence Factors of High Temperature Oxidation for Pt-Modified-Aluminide Bond Coatings

Abstract:

Oxidation of EB-PVD thermal barrier coatings (TBC) deposited and undeposited on nickel base superalloy CMSX-4 with Pt content modified aluminide bond coating have been studied in air at 900, 1000 and 1100 ℃ in order to determine the influence factor of temperature, Pt content and TBC for TGO. It is found that some cracks growth due to the alumina phase transformation and aluminum oxide spallation happened on the surface of low αAl coating TGO. Some voids were formed on the interface between TGO and low aAl bond coating during the initial oxidation period. However, at 900 ℃ inner voids still exist after 300 h oxidation. Thermally grown oxide (TGO) stress trend of samples with TBC was also different compared with that without TBC. The TBC lifetime would be rapidly decreased if the operated oxidation temperature increases