Effect of temperature on the tensile deformation mechanisms of a fourth nickel-based single crystal superalloys

This work conducted tensile experiments from room temperature to 1100 degrees C on a new fourth -generation single crystal superalloys along [001]. The effect of temperature on the tensile properties and deformation mechanism of the alloy were investigated. Results showed that the yield strength of the alloy reached its peak value (1017 MPa) at 850 degrees C. From room temperature to 760 degrees C, the occurrence of stacking faults (SFs) was observed in the gamma matrix channel. From the room temperature to 850 degrees C, the occurrence of stacking faults was observed in the gamma ' phase. The interface dislocation networks appeared at 980 degrees C and above. At room temperature, stacking faults sheared gamma ' phase, in which three types of stacking faults occurred, which controlled deformation process. The main deformation mechanism from 650 degrees C to 850 degrees C was the shearing of gamma ' phase by stacking faults and super dislocations, and at 850 degrees C, stacking faults in different directions of propagation corresponded to the formation of Lomer-Cottrell locks (L -C locks), which greatly increased the yield strength. At 980 degrees C and 1100 degrees C, dislocation climbing and bypassing and anti -phase boundary (APB) coupled dislocation pair shear gamma ' phase became the main deformation mechanism.