Life study of nickel-based single crystal turbine blades: viscoplastic crystallographic constitutive behavior

Abstract Based on dislocation theory, an anisotropic crystallographic constitutive relation has been developed for nickel-based single crystal superalloys. Octahedral {111}〈110〉, {111}〈112〉 and cubic {100}〈110〉 systems are considered. Drag stress and back stress state variables are used to model the local inelastic flow. Results are compared with test data for nickel-based crystal superalloy DD3 at 700°C and 950°C for evaluating the model parameters at these temperatures. The constitutive relation is applied to a finite element program for estimating the strength and life of a nickel-based single crystal turbine blade.