Caracterização experimental de compósitos termoplásticos para uso em processos de manufatura aditiva

Abstract

In this work, was studied the influence of reinforcement and printing orientation on the mechanical behavior of specimens manufactured with filaments of PLA/20 wt% Al (aluminum microparticles), PLA/20 wt% FC (short carbon fiber) and PLA/20 wt% FV (short glass fiber). The specimens were manufactured using fused deposition modeling (FDM) technology. Tests were carried out to analyze the mechanical behavior of the materials studied, in tensile, compression and flexion at four points. The results obtained in the mechanical tests of the specimens manufactured with composite materials were compared with the results of the mechanical behavior of pure PLA, revealing that the influence of the type of reinforcement, namely short fibers or spherical microparticles, is evident. The highest tensile strength was shown for pure PLA, with a print orientation of 45°/-45° (50.83 MPa), and the highest Young's modulus for PLA-Al, with a print orientation of 0 °/90° (3.25 GPa). Pure 0°/90° PLA had the highest compressive strength (65.55 MPa) and the highest Young's modulus (1.53 GPa). The highest flexural strength value can be observed for PLA-FV specimens with 0°/90° (17.79 MPa) print orientation. There was evidence of an increase in flexural strength for 0°/90° PLA-FV samples of 24.23% and 18.52%, compared to 0°/90° pure PLA and 0°/90° PLA-FC samples, respectively. Furthermore, the fracture types and behavior of aluminum particles, carbon fibers, and glass fibers in the PLA matrix were evaluated by scanning electron microscopy analysis. The deformation of the specimens manufactured from pure PLA, PLA-FV, PLA-FC, and PLA- Al was analyzed using the digital image correlation (DIC) technique. The results obtained by DIC were compared with values obtained from four-point bending tests."