Mechanical Properties of Selective Laser Melting‐Processed Multihierarchical Lattice Structure Based on Body‐Centered‐Cubic Unit Cell

Abstract

In this work, three types of multi‐hierarchical lattice structures (MHLSs) with different configurations were designed based on the body‐centered cubic (BCC) unit cell. The designed lattice structures were fabricated using Ti‐6Al‐4V powder as feedstock material through selective laser melting (SLM) technology. The microstructure and surface morphology of the SLM‐formed samples were observed by optical microscopy and scanning electron microscopy, respectively. Theoretical calculation and quasi‐static compression experiment were carried out to investigate their mechanical properties. The result showed that the size error of slave‐cell with small strut diameters was greater than that of master‐cell with larger strut diameters. All MHLSs exhibited superior mechanical properties compared to the BCC lattice structure. Moreover, the specific elastic modulus and specific yield strength of MHLSs with the best mechanical properties were 70.1 % and 51.0 % higher than that of BCC lattice structure, respectively. Meanwhile, theoretical calculation results of the elastic modulus and yield strength were consistent with the results of quasi‐static compression testing. The fracture morphology analysis indicated that the struts of the MHLSs samples exhibit a mixed brittle‐plastic fracture mode, while the nodes exhibit a plastic fracture mode.This article is protected by copyright. All rights reserved.