Effect of Printing Orientation and Layer Thickness on Microstructure and Mechanical Properties of PLA Parts

Abstract

Due to the layer-by-layer printing process, additively manufactured objects frequently display directional dependencies in their structure. It affects the material properties of the fabricated parts concerning various process parameters of the machine. This paper presents the effect of layer thickness and printing orientation on the mechanical properties and microstructure of polylactic acid (PLA)3D printed parts fabricated by Fused Deposition Modeling (FDM). Computer-aided design models of a tensile and compression test specimen were created, conforming to the ASTM: D638 (Type 1 and Type IV) and ASTM D695, respectively. The microstructure was evaluated using a Scanning Electron Microscope (SEM) on the fracture surface during the tensile test and optical microscopy on the compression specimens. The finding shows that a low layer thickness setting contributes to the highest tensile strength in the 0° printing orientation, while a medium and high layer thickness results in a better tensile strength for a 45° and 90° printing orientation. Therefore, printing orientation is more influential than layer thickness in the tensile test. As for the compressive strength, the stress decreases when the layer thickness increases and the low layer thickness setting offers the highest compressive strength at all printing orientations. The microstructure shows more significant interlayer gaps, incomplete filling, and weak bonding on the cross-sectional samples of the fractured tensile surface with lower strength. The 0° printing orientation offers better tensile strength for all layer thicknesses, minimum build time, and good compressive strength compared to other printing orientations.

The Effect of Temperature on the 3D printed Mold Using Polyethylene terephthalate glycol (PETG), Polylactic Acid (PLA) and Stereolithography (SLA)

“…Our findings suggest that molds are susceptible to heat, which can increase the size of the structure. Specifically, we found that PLA structures had the highest increment in size compared to PETG and SLA as research by Hamid et al, [27]. Similarly, the PDMS microchannels fabricated using PLA molds showed the highest increment in size compared to those made with SLA and PETG.…”

“…At the end of the observation, it showed that the SLA mold gave the most accurate size compared to PLA and PETG. SLA also showed the lowest increment, which is very important in molding applications because any difference between the product and the 3D printed mold would affect the application which also reviewed in the research by Hamid et al, [27].…”

Design and Development of Printable Prosthetic Foot using Acrylonitrile Butadiene Styrene (ABS) for Below Knee Amputation (BKA)

“…It is essential for the estimation of the mechanical strength of the structure. It also depends on the parameters of the 3D printing, such as printing orientation and layer thickness [22]. Therefore, we can find out the failure part of the project before the product is fabricated.…”

High Densification Level and Hardness Values of Additively Manufactured 316L Stainless Steel Fabricated by Fused Filament Fabrication

“…Thus, based on the results in this study, it could be reasonably inferred that increasing metal loadings would yield higher hardness values in parts subjected to sintering process provided that the void/defect content is <20%. Nevertheless, despite the promising hardness results, further mechanical testing through tensile tests is necessary to discuss the mechanical properties more comprehensively in the future [34][35][36].…”