Compressive performance and fracture mechanism of bio-inspired heterogeneous glass sponge lattice structures manufactured by selective laser melting

High precision lattice structure (LS) shows great potential applications in aerospace, acoustic, biomedical, and wearable products due to its multifunctional characteristics and excellent mechanical properties. Inspired by lightweight, high-strength, and high-stability glass sponges (GSs), a unique circle-/grid-like heterogeneous glass sponge lattice structure (GSLS) was successfully designed and manufactured by selective laser melting (SLM) with Ti6Al4V alloy. Compared with the commonly used body-centred cubic (BCC), face-centred cubic (FCC), honeycomb and diamond LSs, GSLS displays the strongest compressive properties (E = 1560 MPa, sigma(max) = 40 MPa, sigma(y0)(.2) = 34 MPa, W = 5.95 J). The normalised elastic modulus and normalised compressive strength of GSLS are almost 1.4 and 1.3 times, 2.6 and 2.4 times, 2.7 and 3.5 times, 18 and 8.3 than that of FCC, BCC, honeycomb, and diamond LSs, respectively. Most importantly, unlike the 45 degrees diagonal shear failure of homogeneous BCC and FCC, the FEA simulation reveals that the heterogeneous unit cell in GSLS can enhance the strut connectivity, disperse the stress, and exhibits a unique fracture mechanism of cell-after-cell and layer-by-layer. The fracture mechanism of GSLS can improve the load-bearing capability, maintain strength, and protect its interior and entire integrity during compression. (C) 2022 The Authors. Published by Elsevier Ltd.

Automated summary

High precision lattice structures have great potential applications, and this study successfully designed and manufactured a unique heterogeneous glass sponge lattice structure with strong compressive properties and a unique fracture mechanism, which is expected to be widely used in various fields.