EVALUATING THE SUSTAINABILITY OF ADDITIVELY MANUFACTURED METAL LATTICE STRUCTURES USING A LIFE CYCLE ASSESSMENT APPROACH

Author

• Kamal Kunwar, Southern Illinois University CarbondaleFollow

Date of Award

8-1-2026

Degree Name

Master of Science

Department

Mechanical Engineering

First Advisor

Jung, Sangjin

Abstract

Metal Additive Manufacturing (MAM) has become sustainable due to its ability to reduce material waste and enable lightweight design. However, the environmental performance of complex geometries such as lattice structures remains insufficiently explored. This research evaluates the environmental impacts of Triply Periodic Minimal Surface (TPMS) lattice structures fabricated using the Laser Powder Bed Fusion (L-PBF) process. Four lattice geometries, I-WP, P-Type, Gyroid, and Diamond, were designed with identical dimensions of 20 × 20 × 20 mm, relative density of 30%, and 3D printed using SS316L metal powder on an Xact Metal XM200G system under identical processing conditions. A cradle-to-gate Life Cycle Assessment (LCA) model was developed in GaBi 9.2.1.68 Education software integrating experimentally measured data such as build time, gas consumption, and material usage. Environmental impacts were evaluated using TRACI 2.1 and validated with CML-2001 methodology. Across the lattice geometries, the functional unit Global Warming Potential (GWP) varied from 14.0 to 17.1 kg CO2 eq while cumulative energy demand ranged from 50.2 to 62.9 MJ. These differences are attributed to geometric complexity variations that affect laser scanning behavior. A layer-by-layer slicing analysis further shows that fragmented geometries and discontinuous cross-sections require greater scanning effort, leading to longer build times and increased energy consumption and emissions. By combining experimental data, life cycle modeling, and geometric analysis, this study provides a practical framework for evaluating and improving sustainability in MAM applications.