On the Strain Rate Sensitivity of Fused Filament Fabrication (FFF) Processed PLA, ABS, PETG, PA6, and PP Thermoplastic Polymers

Nectarios Vidakis; Markos Petousis; Emmanouil Velidakis; Marco Liebscher; Viktor Mechtcherine; Lazaros Tzounis

doi:10.3390/polym12122924

On the Strain Rate Sensitivity of Fused Filament Fabrication (FFF) Processed PLA, ABS, PETG, PA6, and PP Thermoplastic Polymers

Polymers (Basel). 2020 Dec 6;12(12):2924. doi: 10.3390/polym12122924.

Authors

Nectarios Vidakis¹, Markos Petousis¹, Emmanouil Velidakis¹, Marco Liebscher², Viktor Mechtcherine², Lazaros Tzounis³

Affiliations

¹ Mechanical Engineering Department, Hellenic Mediterranean University, 71410 Heraklion, Greece.
² Institute of Construction Materials, Technische Universität Dresden, DE-01062 Dresden, Germany.
³ Department of Materials Science and Engineering, University of Ioannina, 45110 Ioannina, Greece.

Abstract

In this study, the strain rate sensitivity of five different thermoplastic polymers processed via Fused Filament Fabrication (FFF) Additive Manufacturing (AM) is reported. Namely, Polylactic Acid (PLA), Acrylonitrile-Butadiene-Styrene (ABS), Polyethylene Terephthalate Glycol (PETG), Polyamide 6 (PA6), and Polypropylene (PP) were thoroughly investigated under static tensile loading conditions at different strain rates. Strain rates have been selected representing the most common applications of polymeric materials manufactured by Three-Dimensional (3D) Printing. Each polymer was exposed to five different strain rates in order to elucidate the dependency and sensitivity of the tensile properties, i.e., stiffness, strength, and toughness on the applied strain rate. Scanning Electron Microscopy (SEM) was employed to investigate the 3D printed samples' fractured surfaces, as a means to derive important information regarding the fracture process, the type of fracture (brittle or ductile), as well as correlate the fractured surface characteristics with the mechanical response under certain strain rate conditions. An Expectation-Maximization (EM) analysis was carried out. Finally, a comparison is presented calculating the strain rate sensitivity index "m" and toughness of all materials at the different applied strain rates.

Keywords: acrylonitrile-butadiene-styrene (ABS); additive manufacturing (AM); fused filament fabrication (FFF); polyamide 6 (PA6); polyethylene terephthalate glycol (PETG); polylactic acid (PLA); polypropylene (PP); strain rate sensitivity; tensile properties; three-dimensional (3D) printing.