Decoupling the Effects of Topology, Density and Residual Stress on Energy Absorption of LPBF Fabricated Ti-6Al-4V TPMS Lattices

Description

This study presents a novel framework to decouple the effects of topology, surface complexity and residual stress on energy absorption behaviour of LPBF fabricated TPMS lattices by considering gyroid, Schwarz-Primitive and Split-P structures with relative densities. The results show that structural fabrication increases wall thickness and structural volume relative to proposed design models, which is primarily ascribed to melt-pool spreading and powder adhesion. Surface morphology using optical profilometry and field emission scanning electron microscopy (FESEM) reveals distinct characteristics in roughness and porous structures among different topologies. In particular, gyroid lattices exhibit higher-amplitude roughness, while Split-P structures show greater surface complexity. Furthermore, the evolution of residual stress predicted by thermomechanical simulation was validated using Williamson–Hall analysis with a reasonable agreement. Relevant deviations were observed within the compressive stress range. Compression tests reveal that energy absorption is mainly influenced by relative density, while topology and surface characteristics play an important role in deformation behaviour and stability. It should be noted that Split-P structure with the relative density of 45% exhibits the highest energy absorption and load-bearing capacity. The findings in this study provide insightful guidance for the design and optimisation of TPMS latices for lightweight, energy-absorbing, and load-bearing applications.

Institutions

• Curtin University

  Western Australia, Perth

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