A viscoplastic crystallographic analysis of a nickel-base single crystal blade

Based on dislocation theory , an unified anisotropic crystallographic constitute has been developed for nickel-base single crystal superalloys. Octahedral {111} <110>, {111} <112> and cubic {100} <110> slip systems are consdered in the model. The constitute utilizes drag stress and back stress state variables to model the local inelastic flow. The model was tested with the experiments of nickel-base crystal superalloy DD3 at 700 °C and 950 °C. The model parameters have been also simultaneously obtained at the two temperatures. The constitute has been implemented into a structure finite element program. The strength and life of a nickel-base single crystal turbine blade have been calculated.