Investigation of the strength of different porous lattice structures manufactured using selective laser melting

Abstract

The introduction and development of additive manufacturing (AM) has led to rapid rise in the innovative design and fabrication of lightweight metallic porous structures. This fabrication technique removes the difficulties presented by conventionally manufactured porous structures. Characteristics of conventionally manufactured porous include simple shapes and high cost because of its complicated manufacturing processes such as roll forming, brazing, and resistance welding. Porous structures with different levels of porosity offer customized mechanical properties, reduction in weight, and material quantity while improving functionality and hence can fulfill the demand for lightweight structures compared to a solid structure. Typically, the structures have high equivalent stiffness, strength, energy absorption, and heat dissipation. This concept is applied in various fields like medical and aerospace for its lightweight property. In this project, CAD models are developed with different porous structures, including BCC, BCC-Z, FCC, FCC-Z, Gyroid, Schwartz, and Diamond. The parts are then fabricated on an EOS M290 metal printer using Inconel 718 powder material. Detailed microstructure and mechanical characterization were carried out in order to obtain an in-depth understanding of the cellular parts with same level of porosity, but different porous structure. This study provides an insight on how to effectively choose the porosity type in a way to maximize the functionality of cellular structures for a specific application.