Characterization of Titanium Lattice Structures Fabricated by Selective Laser Melting Using an Adapted Compressive Test Method

Abstract

This paper investigates the effect of designs and process parameters on the dimensional accuracy and compressive behavior of cellular lattice structures fabricated using selective laser melting (SLM). Two unit cell types, square pyramid and truncated cube & octahedron from the Computer Aided System for Tissue Scaffolds (CASTS), an in-house developed library system were used. Powder adhesions occur on the struts of the lattice structures. The thickness of powder adhesion on the struts decreases with an increase in laser power or laser scan speed. The elastic constant in compression of the lattice structures increases with an increase in relative density, and ranged from 7.93 ± 2.73 MPa to 7.36 ± 0.26 GPa. Analysis of Variance (ANOVA) is also carried out to determine the significance of various process and design parameters on the dimensional accuracy and compressive strength of the lattice structures. The processing parameters, such as laser power and laser scan speed have no significant effect on the elastic constant but have a significant effect on the powder adhesion on the struts, which in turn, affects the dimensional accuracy. However, geometrical design parameters such as unit cell type and strut diameter have significant effects on the elastic constant but not dimensional accuracy of the lattice structures.