The Effect of Volumetric Energy Density on Gyroid Structures Manufactured by Additive Manufacturing: A Review Study

This review investigates the effect of Volumetric Energy Density (VED) on porosity in gyroid structures based on Triply Periodic Minimal Surfaces (TPMS) manufactured by Laser Powder Bed Fusion (LPBF). Ti6Al4V alloy was considered the focal material in this review because of its widespread use in biomedical implant applications, attributed to its high biocompatibility, excellent corrosion resistance, and superior mechanical properties. It is emphasized that VED optimization is a considerably more critical role in the production of complex lattice structures with thin walls, such as gyroid structures, compared to conventional bulk components. The fundamental principles of the LPBF process, melt pool dynamics, and key process parameters (laser power, scan speed, hatch spacing, and layer thickness) are discussed in detail. Examination of LPBF-produced Ti6Al4V components in the literature reveals that insufficient VED values lead to lack-of-fusion porosity, while excessively high VED values result in keyhole-type porosity and thermal stresses. Furthermore, it is stated that the VED parameter must be optimized specifically according to the geometry in order for gyroid structures to achieve the desired mechanical strength, controlled porosity, and osseointegration performance in biomedical implant applications. This review highlights the importance of process optimization in the LPBF manufacturing of complex TPMS structures and provides a comprehensive reference for future studies in the field.