Investigation on Effect of Short-term Overheating on Creep Properties of Nickel-based Single-crystal Superalloy DD6

A rotorcraft aircraft with multiple engines may encounter one engine inoperative (OEI) situation during flight, leading to a surge in the operating powers of the remaining aero-engines. This will cause the turbine blades to suffer short-term overheating, which may affect the service performance and creep life of the blade material. To understand the effect of short-term overheating on the creep property of the nickel-based single-crystal superalloy DD6, widely used in turbine blades, we conduct the non-isothermal creep test considering the OEI stage to study the influence of short-term overheating, and analyze the microstructure of the material after OEI treatment. The test results show that overheating will cause a sudden strain increase in the OEI term and change the subsequent creep process. The short-term overheating causes a significant decrease in the volume fraction of the γ' phase, and the decrease is closely related to whether the γ' phase becomes rafted.