A physically-based computational approach for processing-microstructure-property linkage of materials additively manufactured by laser powder bed fusion

Abstract

A physically-based approach is proposed for evaluating the microstructure-to-property linkage of AlSi10Mg produced by Laser Powder Bed Fusion (L-PBF). The approach includes the simulation of the microstructure evolution during processing and subsequent micromechanical analysis of its deformation behavior. Three-dimensional microstructural model is simulated by coupling the Cellular Automata (CA) model of solidification and the Finite-Difference model of heat transfer. The CA model is based on the nucleation and growth characteristics of the alloy such that the generated microstructure is well aligned with the experiments in terms of the grain structure and texture. Micromechanical analysis for a representative microstructure is performed using Crystal Plasticity (CP) Finite-Element calculations. The sequentially coupled CA and CP models provide a physically-based approach for grain-scale understanding of process-structure-property relationship of L-PBF products. Uniaxial tension along three perpendicular directions is simulated to investigate the deformation behavior of the grain structure. The stress and strain field analyses show an essential anisotropy of the mechanical properties at the grain scale. It is demonstrated that the stress-strain state of the material under uniaxial tension is complex and all stress tensor components make a comparable contribution to the deformation behavior.