Compressive mechanical properties and energy absorption characteristics of SLM fabricated Ti6Al4V triply periodic minimal surface cellular structures

Abstract

This study investigates the compressive mechanical properties and energy absorption characteristics of three types of triply periodic minimal surface (TPMS) Ti6Al4V cellular structures fabricated by selective laser melting (SLM). Based on the SEM observation, the morphology of Ti6Al4V alloy sheet-based TPMS structures was observed, and imperfections of SLM-fabricated cellular structures were investigated. The quasi-static uniaxial compression tests were carried out, and the deformation behavior was recorded by a camera. The result indicated that the compressive mechanical properties had an approximately positive relationship with the relative density of TPMS structures. In addition, the revised Gibson-Ashby prediction models of three sheet-based TPMS structures were established by fitting the compression test results. Furthermore, finite element analysis (FEA) of the compression process was also conducted to facilitate analysis and understanding of the deformation mechanism for TPMS structures. The results also revealed that the energy absorption capacity of TPMS structures increased with the increase in the actual relative density. The mechanical properties, energy absorption, and relative density diagram of sheet-based Ti6Al4V alloy TPMS structures were established to systematically obtain the optimal relative densities of TPMS structures for specific load-bearing and energy absorption applications.