Topological and Mechanical Properties of Different Lattice Structures Based on Additive Manufacturing

Area of Science:

• Materials Science
• Mechanical Engineering
• Additive Manufacturing

Background:

• Additive manufacturing (AM) allows for intricate part geometries previously unattainable.
• Tri-periodic minimal surface (TPMS) structures are increasingly favored in topology optimization for their unique properties.

Purpose of the Study:

• To investigate and compare the mechanical properties of four distinct lattice structures fabricated using selective laser melting (SLM).
• To evaluate the performance of two TPMS sheet structures (Primitive, Gyroid) against two common lattice structures (Bcc, truss).

Main Methods:

• Fabrication of 316L stainless steel specimens using selective laser melting (SLM).
• Numerical simulation and experimental compression testing to determine mechanical properties.
• Analysis of Young's modulus, yield stress, plateau stress, and toughness.

Main Results:

• Mechanical properties are primarily dictated by lattice type, with minimal influence from unit thickness at constant relative density.
• The Gyroid curved structure demonstrated the best overall mechanical properties and energy absorption capabilities.
• Truss lattice structures performed second best, while Bcc and Primitive structures exhibited inferior and unpredictable mechanical behavior.

Conclusions:

• Lattice topology significantly influences mechanical performance and deformation mechanisms in additively manufactured components.
• Gyroid and truss lattice structures offer promising alternatives for applications requiring high strength and energy absorption.
• Further research may be needed to optimize Bcc and Primitive structures or understand their complex deformation modes.