A multi-scale constitutive model for AlSi10Mg alloy fabricated via laser powder bed fusion

Abstract

Additively Manufactured (AM) aluminum alloys find extensive applications in various fields due to their favorable properties. Numerical simulations play a crucial role in reducing experimental costs and enhancing reliability. Developing a reliable constitutive numerical model requires careful consideration of the hierarchical microstructure inherent in AM aluminum alloys. In response, a multiscale constitutive model has been formulated for the AlSi10Mg alloy, fabricated through laser powder bed fusion. This model incorporates crystal plasticity theory and micromechanics-based homogenization methods to establish representative volume elements at different length scales. These scales include the grain scale, polycrystalline scale, and macro scale, thus facilitating a seamless transition between them. The model is calibrated using macroscopic and average phase stress–strain relationships, demonstrating its capability to predict lattice strain in each phase. Additionally, this model incorporates a quantitative analysis of the effects of two-phase structure, melt pool structure, and porosity by adjusting microstructure parameters. The developed model is embedded into a user-defined material subroutine, providing an efficient approach to investigate microstructure-property relationships in AM alloys.