Mechanical Properties and Deformation Behaviors of Layered-Hybrid Lattice Structure Fabricated by Selective Laser Melting

Abstract

Three types of layered-hybrid lattice structures (LHLSs) with different layer thicknesses composed of body-centered-cubic (BCC) and face-centered-cubic (FCC) unit cells are designed and manufactured by selective laser melting using Ti–6Al–4V powder. The microstructure and surface morphologies of the three types of the selective laser melting-formed LHLSs are examined by an optical microscope and scanning electron microscope (SEM), respectively. Quasistatic compression experiments are carried out to investigate the mechanical properties. The results show that the layer thickness has a significant effect on the mechanical properties and deformation behaviors. The elastic modulus, yield strength, and ultimate compressive strength of LHLS increase with the increasing BCC and FCC layer thickness, respectively. Based on the observations of deformation process, a 45° shear band and axial fracture are observed in LHLS-8, and step-like deformation bands are observed in both LHLS-4 and LHLS-2 samples. Besides, the influence of different loading directions on mechanical properties is also investigated; it is found that the ultimate compressive strength loaded in the transverse direction is independent of the layer thickness in LHLSs.