Phase field methods: Microstructures, mechanical properties and complexity

Structural and functional materials inherit their macroscopic properties from the complex microstructures they develop at mesoscale. We discuss here the ability of the phase field method to capture the physical mechanisms at the origin of these complex morphologies in two different situations. First, we analyze the polytwinned microstructures observed in martensitic alloys, and show that, due to the large rotations involved in the accommodation mechanism, a correct modeling of the microstructures requires the use of a geometrically nonlinear model. Second, we present an elasto-viscoplastic phase field model and show its application to the understanding of the rafting phenomena observed in superalloys under creep. (C) 2010 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.