Development of AGAT, a Third-Generation Nickel-Based Superalloy for Single Crystal Turbine Blade Applications

The new third-generation single crystalSingle crystalsuperalloySuperalloy AGAT has been developed for aircraft engine turbine blade applications. Alloy designAlloy design procedure is described and AGAT alloy properties are presented and compared with those of, respectively, first-, second-, and third-generation AM1, CMSX-4 and CMSX-10 alloys. AGAT alloy exhibits high creepCreep resistance at very high temperature (1200 °C) compared with first- and second-generation superalloysSuperalloy while maintaining moderate density (8870 kg m−3) and stable microstructure unlike the third-generation superalloySuperalloy. High cycle fatigue (HCF) and low cycle fatigue (LCF) properties of AGAT alloy are similar to second-generation CMSX-4 alloy. AGAT solution heat treatment allows suppressing the γ/γ′ interdendritic eutectic pools at a temperature 30 °C lower than for CMSX-10 with a shorter duration. OxidationOxidation resistance of AGAT alloy at 1150 °C is lower than that of second but higher than that of third-generation reference superalloysSuperalloy. AGAT shows low sensitivity to secondary reaction zone (SRZ) formation under β-NiPtAl bond coat (BC) and great spallation resistance of YPSZ EB-PVD thermal barrier coating (TBC)Thermal Barrier Coating (TBC) compared with reference alloys. Finally, single crystalSingle crystal turbine blades were successfully manufactured through industrial processes to be tested in engine conditions.