Joining fiber reinforced polyether ether ketone resin matrix composite (PEEK-CFRP) with Ti-6Al-4V titanium alloy to form a composite structure is a promising manufacturing process. Huge difference of material properties is the biggies challenge to join them. Continuous laser welding process is conducted in this experiment to join the two materials. In this study, joints under different welding speeds were obtained. Mechanical properties and microstructures were observed, and the interfacial structures were tested. The results showed that fixed joint could be obtained. As the welding speed decreased, the tensile shear first increased and then decreased. The shear force reached a maximum value of 36.8 N/mm at the speed of 10 mm/s. The quality of joint could be observably affected by welding speed. The formation of bubbles, cracks, and anchor effect at the interface were the main factors affecting the mechanical property of joint. Thus, adhesion failure was the main failure form for CFRP fracture. Ti, Al and some other elements had been diffused across the interface, resulting in the formation of intermediate transition layer. The result of EDS, X-ray and XPS test indicated that CTi0.42V1.58 phase could be formed, and Ti at the interface could react with the oxygen and carbon of CFRP to form TiO2, TiO and TiC, forming a stable joint structure.

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Resin-based carbon fibre reinforced composite (CFRP) with excellent properties has been widely applied in aerospace industry. In this study, polyether ether ketone enforced composite (PEEK-CFRP) and Ti-6V-4V titanium alloy had been joined by laser welding process. Micro-arc oxidation (MAO) process was conducted on the surface of titanium alloy to improve the joint property. Fractures and mechanical properties of joints were analysed. Interfacial microstructures of the joints had been investigated, and the formation mechanism of joint had been figured out. The results showed that after MAO treatment, the joint strength had been greatly improved and the shear strength reached to 42.3 MPa compared with pretreated sample. The wettability of CFRP on titanium alloy was rising with the contact angle of 68.8 . Fracture showed that cohesive failure contributed to the main fracture mode. As joints were formed by both mechanical bonding and chemical bonding, 'anchor-shaped' structures were found in the joint to enhance the mechanical bonding effects due to the flowing of the melted resin. (ÀOH) bonds were identified at the surface of MAOtreated titanium alloy that provided conditions for hydrogen bond interaction. TiO 2 , TiO and Ti-V-C phase were found at interface, whereas Ti-F and Ti-O-F bonds were generated during the welding process, which made great contribution to the chemical bonds between titanium alloy and CFRP.