Morphological Effects at the Local Scale in two-Phase Materials

Abstract

The mechanical behaviour of heterogeneous materials depends not only on the volume fraction of the constitutive phases, but also on their spatial distribution. Most models for the description of such materials are valid for specific configurations only. In this work, experimental results obtained with iron/silver and iron/copper blends, which exhibit several morphologies for a same phase content, are compared to predictions of the classical self-consistent scheme (SCS) [1, 2, 3], pertinent for materials with “perfectly disordered” [4] phase distributions, and of the generalized self-consistent scheme (GSCS) [5], designed for materials with a clear “matrix/inclusion” (MI) morphology, extended to nonlinear behaviour. At the macroscopic scale (the uniaxial elastoplastic tensile curve), no particular morphological effects are detected, but at the local scale (strain averages over each phase), different responses can be described according to the models and are indeed detected experimentally, but with wide quantitative discrepancies between models and experiments. The possible sources of the discrepancies are discussed. Some extensions to the models are suggested.