Manufacturability and Compression Performance of Ti6Al4V Alloy with Triply Periodic Minimal Surface Structures Fabricated by Selective Laser Melting

Abstract

Triply periodic minimal surface (TPMS) structures possess excellent mechanical performance, superior morphological bionics feature, which are considered as the most promising porous structure for bone implants. In this article, the manufacturability and compression performance of the Ti6Al4V alloy with four TPMS structures (Sheet Gyroid, Sheet Diamond, Network Gyroid and Network Diamond) fabricated by selective laser melting (SLM) technology are experimentally carried out, and the corresponding mechanisms are revealed. The results show that the manufacturing deviation of the four TPMS structures show significantly different, which is related to the adhered powder and overhanging phenomena, and an evident anisotropy in surface morphology is observed. The correlations of elastic modulus and yield strength with relative density are established for SLM Ti6Al4V alloy with the four TPMS structures, respectively. Among them, the Sheet Diamond structure shows the best compression performance. The fracture morphology analysis indicates that the TPMS structures exhibit a mixed brittle–plastic fracture mode, and more dimples are observed in Sheet structures which are prone to collective collapsing mechanism. This study provides theoretical guidance for the design of SLM Ti6Al4V alloy with TPMS structures.