Abstract

A scalable technique for making octet microlattice topology mechanical metamaterials with a cell size of 1 mm or less from thin stainless steel sheets is described. The microfabrication process used a perforation operation to form planar truss sheets by the periodic removal of rectangular shaped material. A simultaneous perforation and corrugation operation was also used to create a single layer of trusses with a pyramidal topology. A 3D lattice was then assembled by alternatively stacking the pyramidal and planar truss sheets, taking care to align their nodes to form the octet lattice truss topology. A vacuum brazing method was used to metallurgically bond the assembly. The compressive properties of the microlattices are shown to be comparable to those of much larger cell-size structures of similar material and topology. An assessment of geometric imperfection sensitivity indicates where further mechanical property improvements could be realized by improving the precision of both the perforation and assembly process.

Original languageEnglish (US)
Pages (from-to)147-168
Number of pages22
JournalMaterials and Design
Volume160
DOIs
StatePublished - Dec 15 2018

Keywords

  • Mechanical metamaterials
  • Mechanical properties
  • Microfabrication
  • Octet lattice

ASJC Scopus subject areas

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering

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