Comparison of phenomenological and crystallographic models for single crystal nickel base superalloys. II. Numerical simulations

A numerical procedure to determine the material constants for phenomenologi cal and crystallographic material models is proposed, based on a group of g eneric equations. These models have been developed to describe the anisotro pic behaviour of single crystal nickel base superalloys. The procedure incl udes a number of local optimisation routines to determine each group of mat erial constants using experimental results. By using this procedure for bot h models, the intrinsic characteristics of the models are compared. Overall , both models can describe the fundamental deformation features of single c rystal alloys. However differences are observed in the detailed predictions of the stress and strain curves. The differences between the two models ar e dependent on crystal orientation. The orientations where the two models p redict similar behaviour are consistent with the regions where either octah edral or cubic slip dominates the inelastic deformation. Outside these regi ons the differences between the models are the greatest. (C) 2001 Published by Elsevier Science Ltd.