Coupling Effect of Unit Cell Topology and Forming Orientation on the Ti6Al4V Porous Structures Fabricated Using Selective Laser Melting

Abstract

Selective laser melting (SLM) opens the possibility to produce porous structures with designed mechanical characteristics. This study focuses on the coupling effect between unit cell topology (Dode and body‐centered cubic (BCC)) and forming orientation (horizontal and vertical) with regard to the actual geometric characterization and mechanical properties of SLM produced Ti6Al4V porous structures. The results show that for the mechanical response, there is a coupling effect between forming orientation and unit cell topology. This is most pronounced for the Dode topology, where the compressive and yield strength for specimens produced in vertical orientation are increased with 14.6% and 7.5% compared with those build horizontally. However, for the BCC topology, this effect cannot be seen. The fatigue properties for specimens processed vertically are better compared with those processed horizontally, especially for the BCC topology, it shows an increase of 51.6%. This study presents initial findings on how to handle the selection of unit cell topology and forming orientation for porous structures prepared using SLM, which may be beneficial for different applications.

Quantifying the discrepancies in the geometric and mechanical properties of the theoretically designed and additively manufactured scaffolds

“…Furthermore, the AM technology has made it feasible to produce bone scaffolds with highly complex microstructures, and consequently the AM Increasing the precision of the AM technique is one of the approaches to decrease the discrepancy and thus to produce the as-designed product as precise as possible. However, because the quality of the AM products depends on many factors, such as the AM laser power, the powder size, the post-processing and the internal microstructure of the product Huang et al, 2018], the microstructure of which can be well described using the dimensional parameters. Quantifying the discrepancy in the TPMS scaffolds is far more challenging than quantifying that in the regular lattice structures, because of the presence of the curved surfaces in the TPMS structures, which have to be described using the mathematical equations.…”

Fabrication of a lattice structure with periodic open pores through three-dimensional printing for bone ingrowth

“…The choice of lattice structure may be worth considering, depending on the type of orthopedic implant, although it is not important in most cases, including customized megaprostheses in limb salvage surgery. The mechanical properties of lattice structures are dependent on unit cell conformation 15 , 31 . The yield strength of the various lattice structures reportedly ranges within tens of MPa and a similar level of strength; hence, using lattice structures alone as orthopedic implants may not be suitable 11 , 15 , 31 .…”

“…The mechanical properties of lattice structures are dependent on unit cell conformation 15 , 31 . The yield strength of the various lattice structures reportedly ranges within tens of MPa and a similar level of strength; hence, using lattice structures alone as orthopedic implants may not be suitable 11 , 15 , 31 . Except for some spacers for small bone defects that induce bone regeneration and internal bone bridging, the role of lattice structures in orthopedic implants is limited to providing osteoconduction and mechanical stability, depending on the solid structure.…”

Fabrication of a lattice structure with periodic open pores through three-dimensional printing for bone ingrowth

“…The choice of lattice structure can be worth considering depending on the type of orthopedic implant, although it is not important in most cases, including customized megaprostheses in limb salvage surgery. The mechanical properties of lattice structures are dependent of the unit cell conformation 15,31 . The yield strength of the various lattice structures reportedly range within tens of MPa and this level of strength; hence, using lattice structures alone as an orthopedic implant can be di cult 11,15,31 .…”

“…The mechanical properties of lattice structures are dependent of the unit cell conformation 15,31 . The yield strength of the various lattice structures reportedly range within tens of MPa and this level of strength; hence, using lattice structures alone as an orthopedic implant can be di cult 11,15,31 . Except for some of the spacers for small bone defects that induce bone regeneration and internal bone bridging, the roles of lattice structures in orthopedic implants are limited to osteoconduction and mechanical stability depending on the solid structure.…”