Comparison of phenomenological and crystallographic models for single crystal nickel base superalloys. I. Analytical identification

The general formulations of a phenomenological model and a crystallographic model are developed. These models describe the anisotropic viscoplastic deformation of single crystal nickel base superalloys. The two models are then applied to simple uniaxial loading to identify suitable tests for determining the material constants. A group of generic equations has been identified for both models, which can be applied to uniaxial loading in the [0 0 1] and [1 1 1] orientations. Consequently, a consistent procedure is proposed that determines the material constants for the two models using same experimental results. This permits direct comparison of the intrinsic characteristics of the two models. (C) 2001 Published by Elsevier Science Ltd.