Dual plateau stress of C15-type topologically close-packed lattice structures additive-manufactured by laser powder bed fusion

Imitating crystal structures offers new avenues to design lattice structures composed of unit cells with nodes (act as atoms) and struts (act as atomic bonds). We found out unique dual plateau regions in the stress-strain curves of lattice structures inspired by topologically close-packed (TCP) structure of C15 Laves phase (AB(2)-type intermetallic compounds) and manufactured via the laser powder bed fusion. X-ray computed tomography of compressively deformed lattice structures as well as finite element analysis revealed that the existence of two kinds of units with different relative density caused the dual plateau regions. In addition, the C15 lattice structures exhibited a hybrid deformation mode of bending- and stretch-dominated deformations and can absorb high total energy of 5.0 MJ.m(-3) in two stress levels. (C) 2021 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Automated summary

Imitating crystal structures offers new ways to design lattice structures with unique characteristics in stress-strain curves, such as dual plateau regions due to different relative densities of unit cells. C15 lattice structures exhibit a hybrid deformation mode of bending- and stretch-dominated deformations and can absorb high total energy.