Key Engineering Materials Vol. 1037

Abstract: This paper examines the evolution, processes, and optimization of Fused Deposition Modeling (FDM)/Fused Filament Fabrication (FFF) in additive manufacturing, synthesizing insights from existing literature on its mechanical properties and process parameters. Tracing its origins to rapid prototyping in the late 1980s, the paper highlights the advantages of FDM/FFF, such as cost-effectiveness and reduced material waste, while also addressing challenges like limited part strength. It consolidates knowledge on commonly used materials polylactic acid, acrylonitrile butadiene styrene, polycarbonate, and nylon through comparative analyses of their mechanical and thermophysical properties. The review critically assesses key process parameters, including raster angle, layer height, infill density, infill pattern, build orientation, printing speed, and nozzle diameter, drawing from diverse studies to explore their influence on part quality. Key findings include the potential of a 45°/-45° raster angle and a 0.2 mm layer height to enhance tensile strength, as well as the trade-offs associated with higher infill densities, which improve energy absorption but increase printing time. The paper identifies gaps in dimensional accuracy and material innovation, proposing future research directions to advance FDM/FFF applications across industries.

Abstract: This study investigates the mechanical properties and crack propagation behavior of 3D-printed Acrylonitrile Butadiene Styrene (ABS) by integrating numerical simulations with experimental tensile testing. Utilizing the eXtended Finite Element Method (XFEM) within the Abaqus software, the research examines the damage evolution in ABS specimens under Mode I loading, focusing on the influence of factors such as print orientation, infill density, and layer thickness on mechanical performance. The numerical model, validated through uniaxial tensile tests conducted at a rate of 10 mm/min on ABS specimens with an initial notch, accurately captures the crack propagation process, revealing a two-stage fracture evolution: an initial stable phase over the first 60% of the specimen’s lifetime, followed by rapid crack growth leading to structural failure. Three distinct phases of crack propagation velocity are identified: low velocity during initiation, a quasi-static intermediate phase, and a high-velocity unstable phase, correlating with the evolution of the stress intensity factor. The close agreement between numerical and experimental results underscores the reliability of XFEM for modeling crack behavior, providing critical insights into optimizing 3D printing parameters to enhance the mechanical properties, structural integrity, and durability of ABS components for diverse engineering applications.

Abstract: This study investigates polymer component manufacturing using fused deposition modeling, specifically focusing on the thermoplastic PLA-Cu in open-source FDM machines. Mechanical characteristics are explored, emphasizing infill density, pattern, and nozzle temperature. FDM-produced PLA-Cu specimens, varying in infill (60%, 80%, 100%) and patterns (TRIANGLE, HEXAGON, LINE), reveal superior mechanical properties in those with 100% density, TRIANGLE pattern, and a 210° nozzle temperature. ASTM-standard tests measure tensile and flexural strength, and scanning electron microscopy examines micro-morphology. Results indicate a correlation between increased strain rate and higher yield stress and elastic modulus in PLA-Cu specimens, emphasizing its engineering potential.

Abstract: This study explores the mechanical behavior and performance characteristics of Bio-PETG (Bio-based Polyethylene Terephthalate Glycol) filament processed through Fused Deposition Modeling (FDM) 3D printing. Known for its thermal moldability and high strength, PETG has gained popularity in both additive manufacturing and biomedical applications, particularly in orthopedic implants. The investigation focuses on evaluating the effect of varying infill densities—60%, 80%, and 100%—on key mechanical properties, including flexural strength, compressive strength, impact resistance, and hardness. Test specimens were produced using a Creality Ender-3 FDM printer and assessed in accordance with ASTM standards. Experimental results revealed that specimens with 100% infill density exhibited the highest mechanical strength, achieving flexural and compressive strengths of 62.922 MPa and 47.412 MPa, respectively. Interestingly, samples with 60% infill maintained a reasonable load-bearing capacity while offering advantages in material efficiency and reduced print time. These findings underscore the suitability of Bio-PETG for functional components and emphasize the importance of optimizing infill parameters to achieve a balance between performance and resource utilization.