PSI - Issue 56

Zorana Golubovic et al. / Procedia Structural Integrity 56 (2024) 153–159 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

154

2

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Directed Energy Deposition (DED),

Material jetting, Binder jetting, and Sheet lamination.

Nomenclature AM

Additive manufacturing FDM Fused Deposition Modeling SLA Stereolithography DLP Digital Light Processing ABS

Acrylonitrile Butadiene Styrene

Generally, the most used AM technologies are Material extrusion and Vat photopolymerization, mostly due to machines’ low cost and accessibility of build material. For this research, FDM, SLA, and DLP technologies were selected precisely because of the availability of these AM technologies. When it comes to AM of polymer materials, FDM is one of the most utilized technologies where thermoplastic material in the filament form is melted and extruded through a hot nozzle onto a build platform forming an object in a layer-by-layer manner (Ngo et al., 2018; Samykano et al. 2019; Milovanović et al., 2022). For the utilization of liquid photo -reactive resins, SLA is the most frequently used AM technology. Here, photosensitive liquid resin is cured by a UV light laser beam (Voet et al., 2018). Next, DLP also belongs to Vat photopolymerization AM technology as SLA but, the difference is in the light source. Namely, in contrast to SLA the whole surface of the photopolymer resin vat meant for the light entry is exposed in a single pass (Shah et al., 2020). AM technologies depend on CAD model creation, and most of the technologies need a CAD model in a so-called “STL” file format (abr., Standard Tessellation Language), to be then used in a dedicated slicer software for AM process preparation. The chosen parameters have an influence on final object properties, such as dimensional accuracy, surface roughness, mechanical properties, etc. Most of the technologies share the same parameters: the thickness of the printed layer, build and raster orientation, supporting material addition (for object support during AM process), laser speed and intensity, and post-processing techniques (Abeykoon et al., 2020). The range of applications and possibilities that arise from AM are broadly diverse, leading to the introduction of more materials. As well as with “old” materials, proper characterization of a new material must be perfo rmed and compared with already available materials to estimate the benefits, if possible. In FDM, besides Polylactic Acid (PLA) material Acrylonitrile Butadiene Styrene (ABS) is mostly used thermoplastic polymer. Compared to other FDM materials, ABS stands out with good mechanical properties, but it lacks dimensional accuracy, due to unwanted material shrinking during the cooling process after extrusion. Also, ABS is a more polluting material emitting an unpleasant odor during an AM process (Ngo et al., 201 8; Milovanović et al., 2019). Except for FDM use where the material is in the form of a filament, there is also a parallel material in the form of a resin. This “ABS - like” resin material is available both in SLA and DLP technologies. Applications may cover the production of objects with moderate detail performance, high strength, and in-total satisfactory functionality (Zhu et al., 2020). In engineering, polymer materials may find proper use hence, novel research activities search for different polymer mixtures and types in order to achieve desired mechanical properties of AMed objects. The aim of this particular research is to tensile test this new “ABS - like” resin material and to compare it with standard thermoplastic ABS. In addition to mechanical tests, topography observation using optical microscopy is conducted. 2. Methodology ABS and ABS resin specimens for tensile testing were prepared according to the ISO 527-2 standard (see Fig. 1). Five specimens were prepared for each AM technology, to achieve sufficient repeatability. FDM specimens were AMed on a Creality CR-10 Smart Pro machine (Shenzen, China), and ABS-like resin specimens were made on an SLA (Kings 600 Pro, Shenzen, China) and DLP machine (Creality LD-002R, Shenzen, China). FDM and DLP