Improved Compressive Properties of Lattice Structure Based on an Implicit Surface Hybrid Optimization Design Method via Selective Laser Melting

Abstract

In recent years, the lattice structure produced by additive manufacturing is a type of metal foam that has been increasingly investigated for its unique mechanical properties. However, the conventional Computer-Aided Design (CAD) is inefficient, the triply periodic minimal surfaces are rarely mixed, and the smooth transitions at the boundaries are not considered. In this study, a hybrid optimization design method based on implicit surfaces is proposed, which combines multiple implicit surfaces to achieve the continuous change in the curvature at the structure junctions and reduce the stress concentration. The hybrid lattice structures designed by this method were additively manufactured using 316L alloy via a selective laser melting. The results of the finite element analysis and mechanical compression test show that the hybrid lattice structures generated by this method exhibit a higher yield strength and energy absorption. These works can be used for other implicit surfaces, improve and enrich the types of implicit surfaces, and provide more good choices for practical applications.