Experimental characterization of PLA composites printed by fused deposition modelling

Due to their ability to manufacture highly complex geometries, additive manufacturing technologies have applications in several industrial sectors, such as aerospace, automotive, biomedical and electronics. However, parts made of pure polymeric materials may have limitations in their applications because of the shortcomings in their mechanical properties. Thus, polymer matrix composite materials are used as an alternative to obtaining better technical characteristics, especially for parts obtained by additive manufacturing. In this work, the influence of reinforcement and printing orientation on the mechanical behavior of samples manufactured using filaments of PLA/20 wt% Al (Aluminum microparticles) and PLA/20 wt% CF (carbon fiber reinforcement) were studied. The samples were manufactured using fused deposition modelling (FDM) technology. Tests were carried out to analyze the mechanical behavior of the studied materials, such as tensile, compression, and bending. The results obtained from the mechanical tests of the reinforced filaments were compared with the results on the mechanical performance of pure PLA. The results showed the influence of the type of reinforcement, namely short fibers or microparticles, is evident. The tensile strength, compressive strength, and flexural strength were primarily influenced by the type of reinforcement and Young’s modulus was predominantly influenced by the printing angle and type of reinforcement. The fracture mechanism of composite specimens was infill gaps and interface.