The effect of lattice topology on the thermal and mechanical performance of additively manufactured polymer lattices

Abstract

Additive manufacturing (AM) technology offers a streamlined approach to producing intricate components, reducing both time and costs. Lattice structures play a crucial role in optimising design space by proposing lattices that evaluate a broad spectrum of effective thermal and mechanical properties for building applications. This study aims to assess the impact of lattice topology and variations in the number of unit cells on the K-value, U-value, and compression strength of additively manufactured (AM) polymer lattices. The polymer lattice patterns were created using commercially available 3D printers and PLA polymer filaments. Thermal properties were characterised using a commercial heat flow meter (HFM), and hot-box calorimetry was employed to determine the K-value and U-value, respectively. Additionally, a universal material testing machine was used to investigate the compression strength of all specimens. Based on experimental findings, a scaling law was employed to correlate the effective thermal conductivities of various polymer lattice topologies, estimating the U-value of each one. Furthermore, the study examined how AM process parameters influenced the U-value of polymer lattices. The results indicated that lattice topology and relative density (ρ‾) significantly affected the U-value. The study also demonstrated that polymer lattice structures can be designed to select the optimal lattice configuration. Varying lattice topology had a notable impact on compression strength. It can be concluded that triangular and diamond lattice specimens with ρ‾=40% outperformed other lattice topologies due to their superior mechanical properties, the flexibility of additive manufacturing, and faster manufacturing time. The design of diverse lattice topologies holds promise for incorporating porosity into rigid materials, achieving high thermal and mechanical performance for energy-saving applications.

Keywords

• Additive manufacturing
• Polymer lattice structures
• Polymer-based materials
• Effective thermal conductivity
• U-value
• Compressive strength