An Experimental and FEA Investigation of Deformation Characteristics of Additively Manufactured Ti6Al4V Lattice Structures

Abstract

This study presents a comprehensive experimental and numerical investigation of the mechanical properties and deformation characteristics of additively manufactured Ti6Al4V lattice structures fabricated via Laser Powder Bed Fusion (L-PBF). Two lattice configurations, face-centred cubic (FCC-Z) and body-centred cubic (BCC-Z), both containing struts oriented along the X, Y, and Z directions, were designed with varying porosity levels of 50 %, 60 %, 70 %, and 80 %. The static compression tests were conducted to evaluate the compressive strength, deformation behaviour, and energy absorption capabilities of the lattice structures. Additionally, finite element analysis (FEA) was employed to simulate the deformation mechanisms and predict the mechanical responses under compressive loads. The results revealed that as porosity decreased, both FCC-Z and BCC-Z structures demonstrated increased compressive strength and energy absorption efficiency. Notably, the FCC-Z lattices exhibited superior mechanical performance in terms of compressive strength, specific energy absorption (SEA), and crushing force efficiency (CFE) compared to the BCC-Z lattices. The deformation mechanisms were characterised by layer-by-layer fractures in FCC-Z structures and shear band formation in BCC-Z structures. Furthermore, the FEA results closely aligned with the experimental data, validating the accuracy of the simulation in predicting peak forces, displacement trends, and failure mechanisms. This work provides new insights into the optimisation of Ti6Al4V lattice structures, particularly for applications requiring high energy absorption and mechanical efficiency, such as in the biomedical and aerospace sectors.