Multiscale modeling of the mechanical behavior of IN718 superalloy based on micropillar compression and computational homogenization

Abstract

A multiscale modeling strategy is presented to determine the effective mechanical properties of polycrystalline Ni-based superalloys. They are obtained by computational homogenization of a representative volume element of the microstructure which was built from the grain size, shape and orientation distributions of the material. The mechanical behavior of each grain was simulated by means of a crystal plasticity model, and the model parameters that dictate the evolution of the critical resolved shear stress in each slip system (including viscoplastic effects as well as self and latent hardening) were obtained from compression tests in micropillars milled from grains of the polycrystal in different orientations suited for single, double (coplanar and non coplanar) and multiple slip. The multiscale model predictions of the compressive strength of wrought IN718 were in good agreement with the experimental results.