Lei Zhang, Stefanie Feih, Stephen Daynes, Shuai Chang, Michael Yu Wang, Jun Wei, Wen Feng Lu, Pseudo-ductile fracture of 3D printed alumina triply periodic minimal surface structures, Journal of the European Ceramic Society, Volume 40, Issue 2, 2020, Pages 408-416, ISSN 0955-2219, https://doi.org/10.1016/j.jeurceramsoc.2019.09.048.
Abstract:
Additive manufacturing enables the fabrication of periodic ceramic lattices with controllable micro-architectures. Many studies reported their catastrophic brittle fracture behaviour. However, ceramic lattices may fail by a layer-by-layer pseudo-ductile fracture mode, by controlling micro-architectures and porosities. Moreover, their fracture behaviour can be optimised by introducing strut/wall thickness gradients. This paper investigates the fracture behaviour and the fracture mode transition of ceramic triply periodic minimal surface (TPMS) structures. Alumina TPMS structures with relative densities of 0.14-0.37 are fabricated by ceramic stereolithography. Quasi-static compression tests validate a transition density range for non-graded samples: low (0.25) relative density samples show layer-by-layer pseudo-ductile and catastrophic brittle fracture modes, respectively. The pseudo-ductile failure mode increases the energy absorption performance, enabling load-bearing capacity for a compressive strain up to 50%. With appropriate thickness gradients, graded structures exhibit significant increase of energy absorption without a decrease of fracture strength compared to their non-graded counterparts.
License type:
http://creativecommons.org/licenses/by-nc-nd/4.0/
Funding Info:
Agency for Science, Technology and Research (A*STAR) and the Science and Engineering Research Council (SERC) of Singapore through the Additive Manufacturing Centre (AMC) Initiative – SIMTech-led R&D projects (SERC Grant no. 142 68 00088)