Anisotropic and rate-dependent mechanical properties of 3D printed polyamide 12 - A comparison between selective laser sintering and multi jet fusion

Abstract

Selective laser sintering and multi jet fusion are state-of-the-art 3D printing techniques for polymer manufacturing. In this work, the mechanical performance of 3D printed polyamide 12, which is a common material in additive manufacturing, has been studied. Specimens were printed with both – selective laser sintering and multi jet fusion technologies. Structural orientation and anisotropy of the 3D printed parts have been evaluated through studying the influence of different print orientations on the material properties. The mechanical behaviour has been concluded from tensile tests at several displacement rates. The experiments indicated a non-linear stress-strain behaviour in both cases. A more pronounced anisotropic response, as well as, a more significant rate-dependent behaviour were observed for multi jet fusion compared to selective laser sintering. In addition, laser microscopy technique was used to capture images of the fracture surface of broken specimens to evaluate similarities and differences caused by the 3D printing technologies.