Advances in fused deposition modeling of discontinuous fiber/polymer composites

Fused deposition modeling (FDM) is one of the most widely utilized additive manufacturing techniques by virtue of its numerous merits, such as easy operation, low cost, low energy consumption and little-to-no waste. Based on its simple configuration and extrusion-assisted process, the research and development of this technique is gradually shifting from traditional prototype printing to high-performance composite fabrication. This review provides a panorama for the recent progress of FDM technology in the manufacturing of discontinuous fiber reinforced thermoplastic composites. The entire production chain from the very beginning of FDM filament preparation to the latest stage in large-scale manufacturing process is discussed. The enlightening strategy in multi-axis FDM field is highlighted as it possesses a great potential to manufacture the next-generation composites with superior geometric complexity and flexible fiber alignment. This review also identifies the main challenges and outlook for the future development of this 3D printing technology in fiber reinforced composites.