LIFE STUDY OF NICKEL-BASED SINGLE CRYSTAL TURBINE BLADES - VISCOPLASTIC CRYSTALLOGRAPHIC CONSTITUTIVE BEHAVIOR

摘要

Based an 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] slip 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 degrees C and 950 degrees 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. [References: 10]