An investigation into the properties of 3D printed Ti6Al4V FCC lattice structures with different strut thicknesses

Abstract

Metal additive manufacturing of titanium and its alloys can produce complicated geometries cost-effectively while maintaining biocompatibility. It is known that the material property differences between bone and Ti6Al4V cause stress shielding, leading to bone failure around the implant. Using lattice structures is effective at reducing elastic modulus while improving osteointegration. However, it is important first to characterise the as-printed material to investigate the effects of lattice structures on the bulk material properties. Understanding the microstructure, porosity, and related mechanical properties can discern the bulk material properties of the unit cell. The microstructure of printed samples was found to be martensitic. The printed samples contained porosity with strut thickness deviations ranging from the design from 44.29 % (t = 0.50 mm) to 28.43 % (t = 1 mm). It was found that the high amount of porosity resulted in considerable variation in compression material properties.

Comparative analysis of the subsidence of solid polyetheretherketone (PEEK) and 3D printed lattice titanium interbody fusion cages

“…The mechanical properties and biocompatibility of titanium alloys make them ideal for spinal implant applications in 3D printing. Laser-powder bed fusion (L-BPF) is a precise and accurate 3D printing technology that employs a high-energy laser to melt and fuse metal powder particles layer by layer, enabling the development of intricate lattice structures tailored to human anatomy [1][2][3]. These lattice structures have been shown to reduce the effects of stress shielding and subsidence by lowering the elastic modulus of Ti6Al4V to be more similar to bone [3].…”

“…The utilization of lattice structures in spinal fusion cages offers several significant benefits and has become an area of active research and development [3,[5][6][7][8][9]. The lattice design incorporates an intricate network of interconnected struts, creating a porous and open architecture.…”

“…These unique features provide several advantages for spinal fusion cages. Firstly, the lattice structure allows for reduced stiffness of the cage, which can help match the mechanical properties of the vertebral bone [7,[10][11][12]. By closely mimicking the natural characteristics of bone, the lattice structure promotes optimal load distribution and reduces stress shielding, mitigating the risk of subsidence and implant failure [5,12].…”