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

摘要

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 gamma 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 they matrix, which is rarely reported previously. This finding reported in this work provides us a new idea on high performance single-crystal superalloy design. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.