Mechanical Performance of Functionally Graded Lattice Structures Made with Selective Laser Melting 3D Printing

The selective laser melting (SLM) process is a metal-based 3D printing technology which is capable of fabricating cellular structures for various engineering applications. This study aims to investigate the compressive mechanical performance and energy absorption capability of uniform and functionally graded lattice structures fabricated using this process. A solution heat treatment was carried out to explore its effect on the mechanical properties of the printed Al-Si12 lattice structures. The as-built condition of SLM lattice structures underwent brittle failure and demonstrated non-ideal energy absorption behaviours, while heat treatment was found to significantly improve deformation and energy absorption performance. The deformation behaviour of the heat-treated lattice structure exhibited distinct responses with typical stress strain curves, providing ideal compressive regions. Calculation of energy absorption showed that the gradually denser lattice structure absorbed higher levels of energy than the uniform lattice structure.