Micromechanical characterization of the material response in a PA12-SLS fabricated lattice structure and its correlation with bulk behavior

Abstract

Selective laser sintering (SLS) of polymers has made possible the introduction of lattice-based cells as building blocks of polymer parts, allowing to obtain optimal specific properties. The actual mechanical performance of an SLS part is strongly dependent on the printing direction and part shape. Nevertheless, macroscopic testing is not usually possible due to size restrictions of the fabricated part, as it happens, for example, in lattice-based materials. In this case, microscopic tests performed directly on the lattice surface become fundamental. In this work, the mechanical behavior of SLS PA12 under a wide range of strain rates from 10−3 to 103 s−1 and different printing directions is characterized using macroscopic tests on bulk samples and compared with nanoindentation performed directly on the lattice material surface. An excellent correlation was found between the rate-dependent mechanical behavior obtained at the two scales, validating microscopic techniques for characterizing the mechanical response of SLS fabricated PA12 parts.

Keywords

• Polyamide 12
• Lattice structure
• SLS
• Strain rate dependency
• Nanoindentation
• Nano-impact