Multiscale constitutive modeling of additively manufactured Al-Si-Mg alloys based on measured phase stresses and dislocation density

Zhang, X. X.*; Knoop, D.*; Andr, H.*; Harjo, S.   ; Kawasaki, Takuro   ; Lutz, A.*; Lahres, M.*

To better understand and predict the mechanical properties of additive manufacturing (AM) Al-Si-Mg alloys, developing a physically-based constitutive model is crucial. Among different models, the dislocation-density-based Kocks-Mecking (K-M) constitutive model has been widely used. In-situ neutron diffraction, a powerful method to measure the phase stress and dislocation density in bulk polycrystalline materials under loading, is employed to investigate the AM AlSi3.5Mg1.5 and AlSi3.5Mg2.5 (wt.%) alloys. Based on the present measured and previous experimental data, a multiscale constitutive model is developed for different AM Al-Si-Mg alloys.