Abstract The growing demand for sustainable lightweight materials in the transportation sector has intensified the search for new hybrid structures. This study investigates the joining of short carbon fiber-reinforced polyamide 6 composite (PA6-15CF) to European beech wood using an innovative additive manufacturing technique based on fused filament fabrication (FFF), known as AddJoining. Single-lap hybrid joints were fabricated by directly printing the polymer composite onto the natural wood substrate, achieving an ultimate lap-shear strength (ULSS) of 7.5 ± 1.2 MPa. Micromechanical interlocking and interfacial adhesion contributed to the robustness of the polymer-wood interface, as confirmed by microstructural analysis (OM and SEM) and FTIR spectroscopy, respectively. Fractographic analysis revealed a combination of adhesive and cohesive failure modes, with wood fibers embedded within the polymer matrix, indicating good interfacial compatibility. Furthermore, the joints exhibited remarkable mechanical durability under fatigue testing, achieving a fatigue life of 35% of the ultimate lap-shear force (ULSF) for 10 6 cycles, as estimated by the Weibull distribution with a reliability of 99%. The results demonstrate that AddJoining is a promising manufacturing strategy for producing lightweight, polymer-wood hybrid joints with potential application in sustainable structural design. Graphical abstract
Oliveira et al. (Thu,) studied this question.