The nucleation of δ phases triggered by the stacking faults in a single crystal superalloy

Abstract

Here we investigated the nucleation of the Re, Ru-rich δ phase affected by stacking faults in the γ phase in a 4th generation Ni-based single crystal superalloy during the service at 800°C. The stacking faults in the γ phase were rich in Re and Ru, similar to the observed δ phase. And the stacking fault regions possessed a similar structure to the δ phase, promoting the transformation from γ phase to δ phase. Furthermore, the calculation results indicated that Ru had more significant promoting effects on the δ phase precipitation than Re, providing a reference for the alloy design.

Keywords

• Ni-based single crystal superalloy
• δ phase
• stacking faults
• nucleation