EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

Pure polylactic acid (PLA) and PLA composite with graphene (GPLA) were used for the production of parts by additive manufacturing via 3D printing. Samples were produced by Fused Deposition Modeling (FDM), with the aid of the Repetier-Host V2.1.6 software and the processor of 3D printing models (Cura Engine). The PLA samples were printed varying the printing parameters: percentage of filling (20%, 40%, 60%, 80% and 100%), pattern of printing (concentric, grids and lines) and thickness layer (0.1mm and 0.2mm) and tested for Vickers microhardness evaluation. Using Scanning Electron Microscopy (SEM), it is possible to observe the presence of C-nanotubes with diameters between 100 and 200nm in length up to 8µm in composite structure. Raman Spectroscopy was used to characterize the PLA filament with the identification of a multilayer graphene in GPLA composite. Vickers Microhardness tests using 4 different loads were carried out and three-Way Analysis of Variance (ANOVA) were separately run for each testing load at the 5% level of significance for the printing parameters varied with the R-software. The load of 100g was found as the most suitable for this analysis. The pattern of printing in lines increased the microhardness in general. Its combination with the 20% of filling for both layer thicknesses reached high microhardness, resulting in the best relationship between resistance to penetration, quantity of raw material and printing time. Although there is a commitment to reducing the hardness values in the PLA, the choice of parameters was necessary for the 3D printing of the composite to be the most economical, since the costs of GPLA filaments are high and of low availability.