MICROSTRUCTURAL CHARACTERIZATION OF SHEET LAMINATION-BASED ADDITIVELY MANUFACTURED FIBER- REINFORCED THERMOPLASTIC COMPOSITES

Abstract

Additive manufacturing (AM) of fiber-reinforced composites has garnered significant interest for its versatility in creating intricate parts and rapid prototyping. Short fiber-reinforced composites are typically fabricated through fused deposition modeling (FDM), but they possess several challenges including limited fiber volume fraction, low printing speed, and low throughput for industry scales. Composite-based additive manufacturing (CBAM) is a novel sheet lamination- based AM process, combining non-woven fabric reinforcement with thermoplastic materials to fabricate three-dimensional objects. CBAM offers notable advantages over FDM, including the potential for achieving higher fiber volume fractions and faster production rates, making it a promising technology for further investigation in composite manufacturing. This paper investigates the microstructural characteristics and porosity analyses of non-woven carbon fabric reinforced nylon composites (CF-PA12) manufactured by CBAM and FDM. Test coupons were fabricated in flatwise and edgewise printing orientations. Micro-computed tomography (μCT) analysis revealed that the CBAM specimens contained significantly lower porosity than FDM specimens and had more uniformly distributed smaller porous regions. CBAM flatwise specimens were less porous than edgewise specimens attributed to the comparatively higher number of sheets in edgewise orientation. This study highlights the microstructural characteristics of mechanical test specimens prepared using CBAM and FDM, emphasizing the lower porosity and smaller, more uniformly distributed pores in CBAM specimens which enhance its material integrity and performance, offering a foundation for further development in composite AM technology.