An efficient method for multiscale modelling of the mechanical properties of additively manufactured parts with site-specific microstructures

Abstract

The ability to modulate microstructures at different locations within a part (i.e., site-specific microstructures) can lead to tailored properties and enhanced performance. However, it remains challenging to efficiently model the mechanical response of such materials due to the need for extensive multiscale analysis. To address this issue, we demonstrate through microstructure-based finite element simulations, that the mechanical properties of a randomly distributed two-phase microstructure are primarily dependent on the phase fraction. Therefore, by establishing a mathematical relationship between the phase fraction and mechanical properties, the local material properties can be efficiently calculated from the local microstructure. Later, these site-specific properties were incorporated into a finite element structure to predict the global mechanical properties of the sample part. To validate the effectiveness of the proposed method, low alloy steel with site-specific microstructures was fabricated using binder jet additive manufacturing by depositing varying concentrations of carbon binder at different locations inside the part. We observed a strong agreement between the experimental and simulation stress-strain responses of the steel samples. This method can potentially pave the way for the development of a non-destructive qualification method for additively manufactured parts, as well as provide an efficient approach to multiscale modeling of material behavior, which may help accelerate the design and innovation of novel material systems.