Enhanced interfacial adhesion of CF/PEEK-titanium hybrid laminates via introducing micro-nano layers with multi-walled carbon nanotube networks

An effective and easily-handled strategy for enhancing the interfacial adhesion of CF/PEEK-titanium hybrid laminates was proposed, which was achieved by introducing micro-nano layers with multi-walled carbon nanotube (MWCNT) networks between titanium and PEEK layers via electrophoretic deposition . The optimal deposition condition was explored by setting different concentrations of MWCNTs and times of deposition. Short beam shear tests were conducted at room temperature to characterize the interlaminar shear strength of the hybrid laminates. The results showed that the optimum parameters of deposition were 0.75 mg/mL of MWCNTs concentration and 90 s of deposition time , leading to a 47.8% increase of interlaminar shear strength compared with the sandblasted-only case. The mechanisms for enhancement were explained by micromorphology, apparent contact angle , and roughness analyses, which could be utilized to guide the preparation of CF/PEEK-Ti hybrid laminates with interfacial reinforcement by MWCNTs. Besides, multiple failure modes occurred at the metal-composites interface including a mixed mode of interfacial and cohesive failures , and a large amount of PEEK and carbon fibers remaining on the surface of titanium sheet proved the excellent interlaminar properties of the hybrid laminates.