Thermomechanical behavior and microstructural evolution in nodes and struts of face-centered cubic lattice structures during laser powder bed fusion processing

Abstract

Superior mechanical and functional properties, such as strength, ductility, and energy absorption capabilities, have garnered significant research interest in lattice structures, driven by advancements in additive manufacturing technologies. However, existing limitations in understanding the local thermal histories at the nodes and struts of lattice structures remain a topic to be explored. This study investigates the local thermal histories in lattice structures, focusing on variations in local microstructures. Numerical simulations, combined with detailed microstructure characterizations, reveal that nodes play a crucial role in determining the thermal history of lattice structures. The nodes and struts exhibit difference in grain size, porosity fractions and distortion due to heat dissipation. Furthermore, nodes and struts experience distinct thermal histories due to thermal cycling effects, resulting in microstructure heterogeneity.