Heterogeneous compressive responses of additively manufactured Ti-6Al-4V lattice structures by varying geometric parameters of cells

Abstract

It is vital to develop lattice structures with excellent performance in structural lightweight and multi-functional applications. However, the inherent single mechanical response of the lattice structure limits its application to different physical scenarios. In this study, to achieve the tailored mechanical properties adjustment, we propose a method for creating lattice structures with varying morphology and relative density by adjusting the geometric parameters of the lattice unit cell. A theoretical model for the preliminary prediction of mechanical properties was established, and a uniaxial quasi-static compression experiment was performed on Ti-6Al-4V lattice samples fabricated by laser powder bed fusion. Additionally, the compressive response of these lattice structures was analyzed by numerical simulation. The results show that the adjusting geometric parameters can achieve various heterogeneous mechanical responses, including shear band failure and uniform compression buckling failure. Furthermore, the mechanical properties can be realized in a larger range of compressive modulus from 77.04 MPa to 1073.5 MPa, and compressive strength from 3.96 MPa to 89.23 MPa. Therefore, the customized requirements of structural load-bearing capacity (large modulus and high strength) and energy absorption (stable platform stage) can be met.