Dependence of stacking faults in gamma matrix on low-cycle fatigue behavior of a Ni-based single-crystal superalloy at elevated temperature

Abstract

The LCF behavior of a fourth-generation Ni-based single-crystal superalloy at elevated temperature with different total strain amplitudes has been studied. Notably, the experimental alloy demonstrated a significant work hardening behavior with the total strain amplitude increasing. A great number of SFs with different configurations in the γ matrix was observed. The nature of work hardening was conclusively shown to be dependent upon the high density of SFs and Lomer-Cottrell dislocations in the γ matrix, which is rarely reported previously. This finding reported in this work provides us a new idea on high performance single-crystal superalloy design.