Low cycle fatigue of superalloys: Behaviour of a 4th generation Ni-base single-crystal superalloy TMS-138

摘要

Low cycle fatigue (LCF) of a fourth-generation single-crystal (SC) Ni-base superalloy TMS-138 was studied by comparison with typical third-generation (TMS-75) and second-generation (CMSX-4) Ni-base SC superalloys. TMS-138 exhibits improved LCF behaviour under a condition of the R ratio of 0 at temperatures of 1073 K and 1173 K. The addition of refractory elements resulted in a remarkable improvement of the LCF properties compared to those of the reference superalloys due to the different microstructure developed in TMS-138.