Mechanical Properties and Energy Absorption of Soft–Hard Dual Phase Lattice Structures Manufactured via Selective Laser Melting

Lattice structures with excellent mechanical performance can be achieved through delicate design. In this work, inspired by the soft–hard multiphase crystals, three types of dual phase lattice structures (DPLS) composed of body-centered cubic with Z-struts (BCCZ) matrix phase and face and body-centered cubic with Z-struts (FBCCZ) reinforcement phase were designed and fabricated by selective laser melting (SLM) using 316L stainless steel powder. Quasi-static compression experiment and numerical simulation were carried out to investigate their mechanical properties, energy absorption and deformation behavior. The results showed that the mechanical properties of all DPLS samples were higher than that of single phase BCCZ lattice structure. The four-body diagonal DPLS sample exhibited the highest specific strength and specific stiffness, which was 9.0% and 14.2% higher than single phase BCCZ lattice structure; while, the two-face diagonal DPLS sample had the highest specific energy absorption value of 17.45 J/g. Besides, the experimental and simulated results revealed that the arrangements and volume fraction of reinforcement phase had a significant impact on the performance, deformation behavior and internal stress distribution of the DPLS samples during compressive deformation. Graphical Abstract