The Effect of Strain Rate on the Tensile Deformation Behavior of Single Crystal, Ni-Based Superalloys

Abstract Single crystal Nickel-based superalloys exhibit an anomalous yield point, the stress increasing with temperature to a maximum at around 750 ºC. Here, we demonstrate in alloy CMSX-4 ºC that, although there is virtually no effect of strain rate on initial slow rates second mechanism can initiate leading considerable softening effect. By examining microstructures series interrupted tests, this attributed initiation stacking fault shear after operation secondary slip system. Using high-resolution TEM, dislocation structures are shown be identical both structure and segregation Co, Cr, W, those observed during creep deformation single alloys, conformation dislocations faults differs from that creep. This drop flow low not alloys TMS138A SRR99, former case, improved resistance fourth-generation would require much slower match achievable temperature.