Interlayer bonding improvement of PEEK and CF-PEEK composites with laser-assisted fused deposition modeling

Fused deposition modeling (FDM) is a cost-effective additive manufacturing technique used to fabricate industrial-grade products with intricate designs using high-performance engineering plastics like Polyetheretherketone (PEEK) and their carbon fiber (CF)-reinforced composites. However, the inherent weak interlayer bonding in the FDM results in anisotropic properties, limiting the mechanical strength and hindering widespread applications. In this study, a layer-wise, in-process laser treatment is proposed to enhance the interlayer bonding in the FDM process of both PEEK and CF-PEEK composites. The laser-assisted process selectively treats previously deposited layers, significantly improving the interlayer bonding by enlarging surface contact, reducing voids, and increasing crystallinity. To validate the effectiveness of this method, tensile and bending tests are conducted, accompanied by observations of surface morphology, roughness analysis, and crystallinity measurements. The results demonstrate significant enhancements with over a 20 % increase in tensile strength and 10–20 % increase in bending strength for both materials. This hybrid additive manufacturing method revolutionizes the mechanical properties of printed parts and opens up new possibilities for processing PEEK and CF-PEEK composites.