Application of the double shear specimens in the study of the creep damage and rupture of the nickel-base single crystal superalloys

Double shear creep specimen made of nickel-based single crystal superalloys can be loaded directly on its slip systems, i.e. the applied shear stress is along the slip direction on the slip plane, so that it can be used to study the creep behavior of slip systems. Based on the experiments of the double shear creep specimens in different orientations and the uniaxial tensile creep experiments at 950 °C, the creep and damage behavior of the double shear creep specimens was studied systematically with the help of a creep damage crystallographic constitutive relationship and the finite element method. The results show that there is a near uniform stress state in the shear zone. And the uniform stress is almost independent of the creep time. In the center part of shear zone, only one slip system was activated. The creep damage crystallographic constitutive relationship can be used to model the creep behavior of the double shear creep specimens. And there is a relationship between the creep behavior of the double shear creep specimens and the uniaxial tensile creep specimens. The crystallographic anisotropy can be studied by the double shear creep specimens, which is dependent on activated slip systems and the rafting of γ′ phase.