Multimaterial Bonding of Additively Manufactured Carbon Fiber‐Reinforced Thermoplastics/64 Titanium

The integration of lightweight materials in hybrid structures is critical for achieving energy efficiency in automotive and aerospace industries. This study presents a novel method for directly bonding carbon‐fiber‐reinforced thermoplastics to Ti6Al4V titanium alloy (64Ti) substrates using fused filament fabrication 3D printing. The technique involves 3D printing short carbon fiber‐reinforced polyamide 6 onto sandblasted 64Ti substrates, heated via a hot plate integrated into the 3D printer. Lap‐shear tests reveal that adhesion strength improves with increased fusion time, achieving a maximum shear stress of 27.3 ± 2.2 MPa for 60 min welding. Finite element analysis demonstrates stress concentrations at the adhesion edges and highlights the formation of a fracture process zone with localized plastic deformation and microcrack generation. Additionally, the feasibility of fabricating 3D structures and integrating continuous carbon fiber‐reinforced thermoplastics onto 64Ti substrates is demonstrated. This study advances hybrid material joining techniques by providing a cost‐effective, scalable method for achieving robust metal‐composite bonds suitable for structural applications.