Effect of heat treatment on the properties of D and G lattice structures with different cell sizes fabricated by SLM

Abstract Triply periodical minimal surface (TPMS) structures fabricated by additive manufacturing (AM) technology has been widely used in aerospace and biomedical fields. In this study, the Diamond (D) and Gyriod (G) TPMS structures with the same volume fraction 20%, consistent overall size Φ12*18mm3(unit cell size of 2mm, 3mm and 6mm) were fabricated via selective laser melting (SLM). The effects of heat treatment on mechanical properties, deformation behavior and energy absorption properties of these structures have been systematically investigated. The results show that all as-built D structures exhibit 45° V-shaped fractures, while the fracture pattern of the G structure depends on the unit size. The D202 structure exhibits the highest resistance to compressive failure, and heat treatment can significantly enhance the deformation capability of lattice structures with small cell unit. The study also found that cell unit size has a greater influence on the energy absorption capacity than enhancement by heat treatment and cell structure type. These findings provide inspiration and guidance for the design and heat treatment of lattice structures with both load-bearing and energy-absorbing applications.